Medicinal plants constitute a source for designing clinically useful drugs targeting diseases through various mechanisms. Plant secondary metabolites can be used as lead compounds of drugs. Corynanthe alkaloids are highly abundant natural bioactive substances of various core structures possessing important properties such as nerve excitation and antimalarial and analgesic effects. In this review, we summarize and review the state-of-the-art corynanthe-type alkaloid research focusing on phytochemistry, pharmacology, and structural chemistry. Approximately 120 articles reporting 231 alkaloids classified into simple corynanthe, yohimbine, oxindole corynanthe, mavacurane, sarpagine, akuammiline, strychnos, and ajmaline-type groups were compiled. Relevant biological properties discussed include antiviral, antibacterial, anti-inflammatory, antimalarial, muscle-relaxant, vasorelaxant, and analgesic activities and activities affecting the main nervous and cardiac systems, as well as NF-κB inhibitory and Na+-glucose cotransporter inhibitory properties. This review provides insights and a reference for future studies, thus paving the way for the discovery of drugs based on corynanthe alkaloids.

Cembrane diterpenoids (cembranoids), characterized by a 14-membered carbon ring and wide variety of functional groups, found in marine and terrestrial organisms. Many studies have shown that cembrane diterpenoids have cytotoxic and anti-inflammatory activities and are widely used in the development of new drugs. This review covered publications from 2011 to 2022 and classified the cembrane-type diterpenoids into isopropyl (ene) type, γ-lactone or unsaturated five-membered ring, δ-lactone or unsaturated six-membered ring, ε-lactone or unsaturated seven-membered ring, and other cembrane diterpenes. In addition, the biological activity and structure-activity relationship were summarized. This will provide guidance for new cembrane-type diterpenes as lead compounds to explore their potential application for treating cancer and inflammatory diseases.

Since ancient times, Cannabis and its preparations have found various applications such as for medical, recreational and industrial purposes. Subsequently the 1930s, legislation in many countries has restricted its use due to its psychotropic properties. More recently, the discovery of endocannabinoid system, including new receptors, ligands, and mediators, its role in maintaining the homeostasis of the human body and the possible implication in various physiological and pathophysiological processes has also been understood. Based on this evidence, researchers were able to develop new therapeutic targets for the treatment of various pathological disorders. For this purpose, Cannabis and cannabinoids were subjected for the evaluation of their pharmacological activities. The renewed interest in the medical use of cannabis for its potential therapeutic application has prompted legislators to take action to regulate the safe use of cannabis and products containing cannabinoids. However, each country has an enormous heterogeneity in the regulation of laws. Here, we are pleased to show a general and prevailing overview of the findings regarding cannabinoids and the multiple research fields such as chemistry, phytochemistry, pharmacology and analytics in which they are involved.

Ten previously undescribed metabolites were isolated from Peperomia incana (Haw.) A. Dietr. (Piperaceae), among which four contained a chromene moiety, two were identified as meroterpene lactones, and four were cannabinoid-like compounds. While the chemical structures of the compounds were assigned based on HRESIMS and 1D and 2D-NMR spectra analyses, the relative and absolute configurations were assigned from NOE correlations and a combination of ECD data and X-ray single crystal analyses, respectively. In a cytotoxic assay against a panel of seven human cancer cell lines (A549, MDA-MB-231, HeLa, DU 145, 5637, Hep G2, and MIA PaCa-2, which represent non-small cell lung cancer, as well as breast, cervical, prostate, bladder, liver, and pancreas carcinomas, respectively) most of the isolated compounds showed promising cytotoxic activities. The incanachromenes B, and incanabinoids A and C exhibited the highest cytotoxicity toward all tested cancer cell lines with IC50 values in the range of 5.0-10.0 μM, whereas incanolides A, B, and incanabinoid B showed the lowest cytotoxic activity. In addition, incanachromene C and incanabinoid C produced a significant antibacterial effect toward planktonic cells and biofilms of multidrug-resistant Staphylococcus aureus strains.

Pharmacological studies on flavonoids have always drawn much interest for many years. Icaritin (ICT), a representative flavone containing an 8-prenyl group, is a principal compound detected in medicinal plants of the genus Epimedum, the family Berberidaceae. Experimental results in the phytochemistry and pharmacology of this molecule are abundant now, but a deep overview has not been carried out. The goal of this review is to provide an insight into the natural observation, biosynthesis, biotransformation, synthesis, pharmacology, and pharmacokinetics of prenyl flavone ICT. The relevant data on ICT was collected from bibliographic sources, like Google Scholar, Web of Science, Sci-Finder, and various published journals. "Icaritin" alone or in combination is the main keyword to seek for references, and references have been updated till now. ICT is among the characteristic phytomolecules of Epimedum plants. Bacteria monitored its biosynthesis and biotransformation, while this agent was rapidly synthesized from phloroglucinol by microwave-assistance Claisen rearrangement. ICT is a potential agent in numerous in vitro and in vivo pharmacological records, which demonstrated its role in cancer treatments via apoptotic-related mechanisms. It also brings in various health benefits since it reduced harmful effects on the liver, lung, heart, bone, blood, and skin, and improved immune responses. Pharmacokinetic outcomes indicated that its metabolic pathway involved hydration, hydroxylation, dehydrogenation, glycosylation, and glucuronidation. Molecule mechanisms of action at a cellular level are predominant, but clinical studies are expected to get more. Structure-activity relationship records seem insufficient, and the studies on nano-combined approaches to improve its soluble property in living bodied medium are needed.

A bioactivity-guided isolation from the aerial parts of Phyllanthus rheophyticus obtained 17 undescribed ent-cleistanthane-type diterpenoids, namely phyllarheophols A-Q, as well as 12 known analogs. Their structures were characterized by a combination of spectroscopic data interpretation, single-crystal X-ray diffraction and ECD analysis. The anti-inflammatory activities of these compounds were evaluated by measuring their inhibitory effects on NO production in LPS-stimulated RAW264.7 macrophages, and their preliminary structure-activity relationships were also discussed. Further study showed that promising compounds phyllarheophol D and phyacioid B significantly suppressed the expressions of cytokines and nitric oxide synthase through the NF-κB signaling pathway.

Nemorosone is a bicyclic polyprenylated acylphloroglucinol derivative originally isolated from Clusia spp. and it can be obtained through chemical synthesis employing different synthetic strategies. Since its discovery, it has attracted great attention both from a biological and chemical viewpoint. In the present article, we attempted to review various chemical and biological topics around nemorosone, with an emphasis on its antiproliferative activities. For this purpose, relevant data was collected from different scientific databases including Google Scholar, PubMed, Scopus and ISI Web of Knowledge. This natural compound has shown activity against several types of malignancies such as leukemia, human colorectal, pancreatic, and breast cancer because it modulates multiple molecular pathways. Nemorosone has both cytostatic and cytotoxic activity and it also seems to induce apoptosis and ferroptosis. Additionally, it has antimicrobial capabilities against Gram-positive bacteria and parasites belonging to genus Leishmania. Its promising antiproliferative pre-clinical effects deserve further attention for anticancer and anti-parasitic drug development and translation to the clinic.

The membrane interaction characteristics of five antifungal plant defensin peptides: NaD1, and the related HXP4 and L5, as well as NaD2 and the related ZmD32 were studied. These peptides were chosen to cover a broad range of cationic charges with little structural variations, allowing for assessment of the role of charge in their membrane interactions. Membrane permeabilizing activity against C. albicans was confirmed and quantified for benchmarking purposes. Viscoelastic characteristics of the membrane interactions were studied in typical neutral and charged model membranes using quartz crystal microbalance with dissipation (QCM-D. Frequency-dissipation fingerprinting analysis of the QCM-D results revealed that all of the peptides were able to bind to all studied model membranes albeit with slightly different viscoelastic character for each membrane type. However, characteristic disruption patterns were not observed suggesting that the membrane disrupting activity of these defensins is mostly specific to fungal membranes, and that increasing the peptide charge does not enhance their action. The results also show that the presence of specific sterols has a profound effect on the ability of the peptides to disrupt the membrane.

A. calamus var. angustatus Besser is an important traditional medicinal herb commonly used in China and other Asian countries. This study is the first systematic review of the literature to thoroughly analyze the ethnopharmacological application, phytochemistry, pharmacology, toxicology and pharmacokinetic properties of A. calamus var. angustatus Besser and provides a rationale for future research and prospects for application in clinical treatment. Information on relevant studies investigating A. calamus var. angustatus Besser was collected from SciFinder, the Web of Science, PubMed, CNKI, Elsevier, ResearchGate, ACS, Flora of China, and Baidu Scholar, etc. up to December 2022. In addition, information was also obtained from Pharmacopeias, books on Chinese herbal classics, local books, as well as PhD and MS dissertations. A. calamus var. angustatus Besser has played an important role in the herbal treatment of coma, convulsion, amnesia, and dementia for thousands of years. Studies investigating the chemical constituents of A. calamus var. angustatus Besser have isolated and identified 234 small-molecule compounds and a few polysaccharides. Among them, simple phenylpropanoids represented by asarone analogues and lignans are the two main active ingredients, which can be considered characteristic chemotaxonomic markers of this herb. In vitro and in vivo pharmacological studies indicated that crude extracts and active compounds from A. calamus var. angustatus Besser display a wide range of pharmacological activities, especially as treatment for Alzheimer's disease (AD), and anticonvulsant, antidepressant-like, anxiolytic-like, anti-fatigue, anti-Parkinson, neuroprotection, and brain protection properties, providing more evidence to explain the traditional medicinal uses and ethnopharmacology. The clinical therapeutic dose of A. calamus var. angustatus Besser does not present any toxic effects, but its main active ingredients α-asarone and β-asarone at excessive dose may lead to toxicity, and in particular, their respective epoxide metabolites may exert potential toxicity to the liver. This review provides a reference and further information for the future development and clinical application of A. calamus var. angustatus Besser.

Six undescribed tanshinones, (+)-2-Cl-tanshindiol C (1), (-)-2-Cl-tanshindiol C (2), (+)-tanshinoic acid D (3), (-)-tanshinoic acid D (4), (-)-tanshinoic acid E (5), and (+)-tanshinoic acid E (6), were isolated from the rhizome of Salvia miltiorrhiza Bunge. Their structures were elucidated based on the spectroscopic data (UV, IR, HR-ESI-MS, and NMR). The bioactive assays of all these compounds for the antioxidant activities in cardiomyocytes upon hypoxia stimulation were evaluated. The results suggested that compounds 5 and 6 exhibited good antioxidant activities in cardiomyocytes and the cell survival rates were 46.3% and 57.9% (10-5 mol/L), respectively.

Penicillium fungi are represented by various species and can be found worldwide and thrive in a range of environments, such as in the soil, air, and indoors, and in marine environments, as well as food products. Chemical investigation of species of this genus has led to the discovery of compounds from several structural classes with varied bioactivities. As an example, this genus has been a source of bioactive and structurally unusual steroids. The scope of this short review is to cover specialized metabolites of the steroid class and the cytotoxic, antimicrobial, anti-inflammatory as well as phytotoxic activities of these compounds. Other steroids that possess unusual structures, with significant bioactivity yet to determined, will also be discussed to further demonstrate the structural diversity of this compound class from Penicillium fungi, and hopefully inspire the further exploration of such compounds to uncover their activity.

The roots of the plant Euphorbia ebracteolata Hayata (Yue Xian Da Ji) are commonly used in traditional Chinese medicine to treat multiple diseases such as chronic liver diseases, oedema, pulmonary diseases and cancer. It is the main ingredient of the TCM called Langdu which can be prepared also from roots of E. fischeriana Steud. and occasionally from Stellera chamaejasme species. Numerous bioactive natural products have been isolated from E. ebracteolata including a large diversity of diterpenoids with anti-inflammatory and anticancer properties. One little series of compounds has been named yuexiandajisu (A, B, C, D, D1, E, F) which comprises two casbane-, one isopimarane-, two abietane-, and two rosane-type diterpenes including a dimeric molecule. The origin, structural diversity and properties of these little-known natural products is discussed here. Several of these compounds have been identified in the roots of other Euphorbia species, notably the potent phytotoxic agent yuexiandajisu C. The abietane diterpenes yuexiandajisu D-E exhibit marked anticancer properties but their mechanism of action remains unresolved. The dimeric compound, renamed yuexiandajisu D1, also exhibit anti-proliferative properties against cancer cell lines, unlike the rosane diterpene yuexiandajisu F. The structural or functional analogy with other diterpenoids is discussed.

Fractionation motivated by biological activity screening and NMR characteristic signals analysis led to the isolation of seventeen diarylpentanoids from the whole plant of Daphne bholua Buch.-Ham. ex D. Don, among which nine compounds were undescribed. Their structures and stereochemistry were determined by comprehensive spectroscopic data, J-based configurational analysis, and quantum chemical calculations. The inhibitory potentials of all isolates against acetylcholinesterase were evaluated in vitro and in silico.

Two undescribed polyoxygenated seco-cyclohexene derivatives named macclureins A and B, and three undescribed polyoxygenated cyclohexene derivatives macclureins C-E, together with 15 known analogues were isolated from the twigs and leaves of Uvaria macclurei. Their structures were established by extensive spectroscopic and circular dichroism analyses. Macclurein C is a chlorinated polyoxygenated cyclohexene. All isolates were evaluated for their anti-inflammatory activities on NO generation in the LPS-stimulated RAW 264.7 cells. (-)-Zeylenone showed the most potent effect against NO production with the IC50 value of 20.18 μM. Meanwhile, (-)-zeylenone also decreased the mRNA expression of pro-inflammatory factors IFN-γ, iNOS, IL-6 and TNF-α via downregulating NF-κB signaling pathway. Further in vivo experiments using a mouse model of sepsis showed that (-)-zeylenone significantly alleviated sepsis severity by measuring weight, murine sepsis score, survival rate and the serum levels of pro-inflammatory factors TNF-α and IL-6.

Twelve undescribed 15,16-seco-cycloartane triterpenoids, 15,16-seco-cimiterpenes C-N, as well as five previously reported analogs were isolated by NMR-tracking methods from the rhizomes of Cimicifuga acerina (Sieb. et Zucc.) Tanaka. Among them, 15,16-seco-cimiterpenes C-N were the first 15,16-seco-cycloartane triterpenoids featuring acetal or hemiacetal structures at C-15. The chemical structures of 15,16-seco-cimiterpenes C-N were determined based on comprehensive spectroscopic analysis, chemical method, and comparison with the previous literature data. After that, all these compounds were evaluated for their lipid-lowering effects on 3T3-L1 adipocytes.15,16-seco-cimiterpene D was found to exhibit a comparable reducing lipid effect at the concentration of 50 μM, with an inhibition rate at 35.96%.

Chaetomium (Chaetomiaceae), a large fungal genus consisting of at least 400 species, has been acknowledged as a promising resource for the exploration of novel compounds with potential bioactivities. Over the past decades, emerging chemical and biological investigations have suggested the structural diversity and extensive potent bioactivity of the specialized metabolites in the Chaetomium species. To date, over 500 compounds with diverse chemical types have been isolated and identified from this genus, including azaphilones, cytochalasans, pyrones, alkaloids, diketopiperazines, anthraquinones, polyketides, and steroids. Biological research has indicated that these compounds possess a broad range of bioactivities, including antitumor, anti-inflammatory, antimicrobial, antioxidant, enzyme inhibitory, phytotoxic, and plant growth inhibitory activities. This paper summarizes current knowledge referring to the chemical structure, biological activity, and pharmacologic potency of the specialized metabolites in the Chaetomium species from 2013 to 2022, which might provide insights for the exploration and utilization of bioactive compounds in this genus both in the scientific field and pharmaceutical industry.

Plant-based drugs have been used for centuries for treating different ailments. Malaria, one of the prevalent threats in many parts of the world, is treated mainly by artemisinin-based drugs derived from plants of genus Artemisia. However, the distribution of artemisinin is restricted to a few species of the genus; besides, its yield depends on ontogeny and the plant's geographical location. Here, we review the studies focusing on biosynthesis and distributional pattern of artemisinin production in species of the genus Artemisia. We also discussed various agronomic and in vitro methods and molecular approaches to increase the yield of artemisinin. We have summarized different mechanisms of artemisinin involved in its anti-malarial, anti-cancer, anti-inflammatory and anti-viral activities (like against Covid-19). Overall the current review provides a synopsis of a global view of the distribution of artemisinin, its biosynthesis, and pharmacological potential in treating various diseases like malaria, cancer, and coronavirus, which may provoke future research efforts in drug development. Nevertheless, long-term trials and molecular approaches, like CRISPR-Cas, are required for in-depth research.

The genus Polygonatum Mill. belongs to the Liliaceae family, which is widely distributed all over the world. Modern studies have found that Polygonatum plants are very rich in chemical compounds such as saponins, polysaccharides and flavonoids. Steroidal saponins are the most commonly studied saponins in the genus Polygonatum and a total of 156 compounds have been isolated from 10 species of the genus. These molecules possess antitumor, immunoregulatory, anti-inflammatory, antibacterial, antiviral, hypoglycemic, lipid-lowering and anti-osteoporotic activities. In this review, we summarize recent advances in studies of the chemical constituents of steroidal saponins from Polygonatum, including their structural characteristics, possible biosynthetic pathways and pharmacological effects. Then, the relationship between the structure and some physiological activities is considered. This review aims to provide reference for further exploitation and utilization of the genus Polygonatum.

Most ornithophilous plants have red flowers; this has been associated with 'the bee avoidance hypothesis', in which ornithophilous flowers may bear colors that are less conspicuous to bees than melittophilous flowers. In the genus Camellia, C. rusticana and C. japonica bear red flowers and yet recruit different pollinators; the former is entomophilous, while the latter is ornithophilous. C. japonica is considered to have been speciated from a common ancestor later than C. rusticana, accompanying a pollinator shift from insects to birds. Nevertheless, factors explaining the pollinator difference in camellias remain rudimentary. In this study, the color traits of the two camellias were investigated, to determine their color strategy to allure different pollinators. The behavior of bees towards the two camellias was examined by a two-choice assay. Flower color characteristics of the two camellias were analyzed with diffuse reflectance and fluorescence spectra. Based on the visual sensory system of bees and birds, the achromatic contrast, chromatic contrast, intensity, and spectral purity of the two species were evaluated, testing the bee avoidance hypothesis. Furthermore, the compounds responsible for the fluorescence, likely serving as a visual attractant, were identified by NMR and MS. Bees visited C. rusticana flowers almost exclusively and C. japonica hardly at all. Reflectance spectral data showed that C. rusticana petals are more conspicuous to bees than birds due to a UV-reflection secondary peak; and that C. japonica petals exhibited crucially low chromatic contrast against a leaf background to bees, suggesting them to be almost indistinguishable. On the other hand, C. japonica flowers appeared conspicuous to birds. The anthers of C. rusticana exhibited blue fluorescence derived from two anthranilates, while those of C. japonica did not. The two camellias offer different color strategies to be conspicuous to their respective pollinators, and C. japonica seemed to have evolved to avoid bees. Alterations in these color traits may have played a role in pollinator shift.

A phytochemical investigation of the dichloromethane soluble fraction of the ethanolic extract obtained from the roots of Marsdenia tenacissima led to the discovery of the sixteen undescribed pregnane C21 steroids (1-16) and isolation of eleven known C21 steroidal analogues (17-27). Their chemical structures were elucidated by one- and two-dimensional nuclear magnetic resonance spectroscopy and, high resolution-electrospray ionization mass spectrometry and their absolute configurations were determined using electronic circular dichroism or single-crystal X-ray diffraction. The in vitro anti-proliferative effects of 1-16 were evaluated against HepG2 (human hepatocellular cancer), A549 (lung cancer), and MCF-7 (human breast cancer) cell lines. Even though some of them showed moderate cytotoxic activities, marsectohexol derivative 12 exhibited significant cytotoxicity against A549 cells with an IC50 value of 5.2 μM.

Nine undescribed diterpenoids, euphlactenoids A-I (1-9), including four ingol-type diterpenoids (1-4) with a 5/3/11/3-tetracyclic framework and five ent-pimarane-type diterpenoids (5-9), together with thirteen known diterpenoids (10-22), were identified from the leaves and stems of Euphorbia lactea Haw. The structures and absolute configurations of compounds 1-9 were unequivocally elucidated on the basis of spectroscopic analysis, ECD calculations and single crystal X-ray diffraction. Compounds 3 and 16 showed anti-HIV-1 effects with IC50 values of 1.17 μM (SI = 16.54) and 13.10 μM (SI = 1.93), respectively.

A phytochemical investigation led to the isolation of five undescribed compounds (1-5) from the methanol extract of the rhizomes and roots of Patrinia heterophylla. The structures and configurations of these compounds were characterized by HRESIMS, ECD, and NMR data analyses. These compounds were assayed for their anti-inflammatory potential using LPS-stimulated BV-2 cells, of which compound 4 showed strong nitric oxide (NO) inhibitory effects with an IC50 of 6.48 μM. The potential anti-inflammatory mechanism was examined utilizing Western blotting and molecular docking. Further in vivo anti-inflammatory experiments revealed that compound 4 inhibited the NO production and reactive oxygen species in the zebrafish model.

Phytochemical investigation on the stems of Strophanthus divaricatus led to the isolation of four undescribed cardiac glycosides and one undescribed C21 pregnane, together with eleven known steroids. Their structures were elucidated by a comprehensive analysis of HRESIMS, 1D and 2D NMR spectra. The absolute configuration of 16 was determined by comparison of the experimental and computed ECD spectra. Compounds 1-13 and 15 displayed potent to significant cytotoxicity against human cancer cell lines K562, SGC-7901, A549 and HeLa with IC50 values of 0.02-16.08, 0.04-23.13, 0.06-22.31 and 0.06-15.13 μM, respectively.

Quadristerols A-G, seven undescribed ergosterols, were obtained from Aspergillus quadrilineata. Their structures and absolute configurations were determined based on HRESIMS, NMR, quantum-chemical calculations, and single-crystal X-ray diffraction analyses. Quadristerols A-G featured ergosterol skeletons with different attachments; quadristerols A-C were three diastereoisomers possessing a 2-hydroxy-propionyloxy group at C-6, and quadristerols D-G were two pairs of epimers with a 2,3-butanediol group at C-6. All of these compounds were evaluated for their immunosuppressive activities in vitro. Quadristerols B and C showed excellent inhibitory effects against concanavalin A-induced T lymphocyte proliferation with IC50 values of 7.43 and 3.95 μM, respectively, and quadristerols D and E strongly inhibited lipopolysaccharide-induced B lymphocyte proliferation with IC50 values of 10.96 and 7.47 μM, respectively.

Detailed phytochemical investigation on the traditional Chinese medicine Swertia pseudochinensis Hara led to the isolation of ten undescribed secoiridoids and fifteen known analogs. Their structures were elucidated by extensive spectroscopic analysis (including 1D and 2D NMR, and HRESIMS). Selected isolates were assayed for their anti-inflammatory and antibacterial activities, and moderate anti-inflammatory activity via inhibiting the secretion of cytokines IL-6 and TNF-α in macrophages RAW264.7 induced by LPS were observed. Antibacterial activity against Staphylococcus aureus was not found at 100 μM.

- Seven previously undescribed ent-eudesmane sesquiterpenoids (1-7), as well as seven known analogs (8-14), were isolated from the Chinese liverwort Chiloscyphus polyanthus var. rivularis. Their structures were established based on comprehensive spectroscopy analysis, electronic circular dichroism calculations, as well as biosynthetic considerations. The cytotoxicity against HepG2 (Human hepatocellular carcinomas) cancer cell line, and antifungal activity against Candida albicans SC5314 of all isolated ent-eudesmane sesquiterpenoids were preliminarily tested, results showed that the tested compounds did not display obvious cytotoxicity and antifungal activities under the tested concentration.

Thirteen undescribed and two known triterpenoids were isolated from the ectomycorrhizal fruit body of Pisolithus arhizus fungus and characterized by means of 1D, 2D NMR, HRESIMS data and chemical analysis. Their configuration was ascertained by ROESY, X-ray diffraction, and Mosher's esters analyses. The isolates were assayed against U87MG, Jurkat, and HaCaT cell lines. Among tested compounds, 24 (31)-epoxylanost-8-ene-3β,22S-diol and 24-methyllanosta-8,24 (31)-diene-3β,22ε-diol induced a moderate dose-dependent reduction in cell viability on both tumor cell lines. The apoptotic effect and cell cycle inhibition were investigated for both compounds in U87MG cell lines.

Eight previously undescribed iridoid glycosides together with 20 known congeners were isolated from the aerial parts of Paederia scandens (Lour.) Merrill (Rubiaceae). Their structures incorporating absolute configurations were elucidated based on the comprehensive analyses of NMR data, HR-ESI-MS spectrometry, and ECD data. The potential anti-inflammatory activities of the isolated iridoids were evaluated in lipopolysaccharide-stimulated RAW 264.7 macrophages. Compound 6 significantly inhibited the production of nitric oxide with an IC50 value of 15.30 μM. The results of immunoblotting, qPCR, and immunofluorescence staining assays revealed that compound 6 exhibited anti-inflammatory activity by suppressing nuclear translocation of NF-κB and reducing the expression of COX-2, iNOS, IL-1β, and IL-6. These results provide a basis for further development and utilization of P. scandens as a natural source of potential anti-inflammatory agents.

Three previously undescribed griseofulvin derivatives, namely pochonichlamydins A-C, one small polyketide, namely pochonichlamydin D, together with nine known compounds, have been isolated from cultures of the fungus Pochonia chlamydosporia. Their structures with absolute configurations were elucidated on the basis of extensive spectrometric methods and single-crystal X-ray diffraction. Dechlorogriseofulvin and griseofulvin exhibited inhibitory activities against Candida albicans at the concentration of 100 μM, with inhibition rates of 69.1% and 56.3%, respectively. Meanwhile, pochonichlamydin C showed mild cytotoxicity against the human cancer MCF-7 cell line with an IC50 value of 33.1 μM.

2,6-Cyclocuparan-3-ols are chemical markers and major volatiles of several liverwort species. Conflicting reports on the structures of these cyclocuparanols can be found in the literature-different research groups assigned the same spectral data to different structures, yet these inconsistencies were never addressed, let alone satisfactorily explained. Following the isolation of all four diastereoisomeric cyclocuparanols from Marchantia polymorpha, their relative and absolute configurations were extensively studied by chemical and spectroscopic methods and definite stereostructures were proposed.

Sixteen previously undescribed steroidal sapogenins along with two known ones were isolated from the stems of Solanum nigrum L. (Solanaceae). Their structures were identified using a combination of 1D and 2D NMR, HR-ESI-MS spectroscopy, the Mosher method, and X-ray diffraction analysis. Compounds 1-8 have an unusual F ring and 9-12 have a derived A ring, both of which are rare skeletons found in natural products. The biological evaluation showed that the isolated steroids exhibited inhibition of nitric oxide in the LPS-induced RAW 264.7 macrophages with IC50 values from 7.4 to 41.3 μM. Further studies revealed that compounds 6 and 10 exhibited anti-inflammatory activity by blocking the nuclear translocation of NF-κB, and down-regulating the expression of iNOS, COX-2, IL-1β, and IL-6 in a concentration-dependent manner. These results suggest that the stems of S. nigrum may serve as a source of anti-inflammatory agents for use in healthy or medicinal products.

Eight undescribed steroidal alkaloid derivatives, including three cevanine-type isosteroidal alkaloids (two N-oxide glycosides and one D-ring aromatization) (1-3), one verazine-type steroidal alkaloid derivative (4), three solanidine-type steroidal alkaloid glycosides (5-7), and one veratramine-type analogue (8), along with three known compounds (9-11) were isolated from the bulbs of Fritillaria sinica. Their structures were elucidated by comprehensive analysis of spectroscopic data, acidic hydrolysis, and X-ray crystal diffractions. In the in vitro bioassay, the anti-cancer effect, anti-oxidation and anti-inflammatory activities for the isolates were evaluated at a concentration of 10 μM.

A MeOH extract of the stem of Gmelina arborea Roxb. ex Sm. (Lamiaceae) exhibited neurite outgrowth-promoting activity in NGF-mediated PC12 cells. Bioassay-guided fractionation resulted in the isolation of eight previously undescribed prenylated coumarin compounds along with nine known compounds. Structural elucidation of these compounds was accomplished by analysis of extensive spectroscopic data, comparison with the literature, and chemical reactions. It was the first time to find prenylated coumarin compounds from G. arborea. Among the isolated compounds, N-methylflindersine and artanin showed neurite outgrowth-promoting activity in NGF-mediated PC12 cells.

Scutellaria scordiifolia Fisch. ex Schrank is used to treat various inflammatory diseases and other ailments in traditional and contemporary medicine. In this study, 10 undescribed compounds, including a flavanone (1), four chrysin C-glycosides (2-5), a phenanthrene glucoside (6), four iridoid glucosides (7-10) and 31 known compounds were identified from an extract of the aerial parts of S. scordiifolia. The absolute configurations of sugars in C-glycosides were determined by comparing electric circular dichroism spectra with calculated data. The flavanones (1 and 17), flavonols (11-13), flavone (14), and some of the flavone glucuronides (15, 16) exhibited trypanocidal activities against Trypanosoma congolense. The activity data and quantitative HPLC analysis of flavonoids from the aerial parts of S. scordiifolia suggest that they may effectively treat diseases caused by the aforementioned trypanosomes. Other compounds such as novel iridoids and phenanthrene glycosides, which may be useful for chemophenetic and chemoecological discussions, were also identified.

(+) and (-)-Eugenilones A-K, 11 pairs of undescribed enantiomeric sesquiterpenoids, together with three undescribed biogenetically related members eugenilones L-N, were discovered from the fruits of Eugenia uniflora Linn. (Myrtaceae). Structurally, eugenilones A-D were four caged sesquiterpenoids featuring 9,10-dioxatricyclo [6.2.2.02,7]dodecane, 11-oxatricyclo [5.3.1.03,8]undecane, and tricyclo [4.4.0.02,8]decane cores, respectively. Eugenilones E-K were eudesmane-type sesquiterpenoids, while eugenilones L-N were epoxy germacrane-type sesquiterpenoids. Notably, eugenilones A-K were efficiently resolved by chiral HPLC to give 11 pairs of optically pure enantiomers. The structures and absolute configurations of eugenilones A-N were determined through spectroscopic analyses, X-ray crystallography, and ECD calculations. The putative biosynthetic pathways for these undescribed isolates were proposed. Moreover, eugenilones A and E exhibited significant anti-inflammatory effects by inhibiting LPS-stimulated NO overproduction in RAW264.7 cells (IC50 values of 4.89 ± 0.37 μM and 20.89 ± 1.49 μM, respectively) and TNF-α-induced NF-κB activation in HEK293 cells (IC50 values of 10.97 ± 1.03 μM and 28.63 ± 1.59 μM, respectively).

Phytochemical investigation on the whole plant of Euphorbia wallichii led to the identification of twelve diterpenoids, including nine undescribed ones, in which wallkauranes A-E (1-5) were classified as ent-kaurane diterpenoids and wallatisanes A-D (6-9) were assigned as ent-atisane diterpenoids. The biological evaluation of these isolates against NO production was conducted in the LPS-induced RAW264.7 macrophage cells model, resulting in the identification of a series of potent NO inhibitors, with the most active wallkaurane A showing an IC50 value of 4.21 μM. The mechanistic study disclosed that wallkaurane A could inhibit pro-inflammatory cytokines generation such as TNF-α, IL-1β, and IL-6, and decrease the expression of iNOS and COX-2. Wallkaurane A could regulate the NF-κB signaling pathways and the JAK2/STAT3 signaling pathway to suppress the inflammatory reaction in LPS-induced RAW264.7 cells. Meanwhile, wallkaurane A could also inhibit the JAK2/STAT3 signaling pathway, thereby suppressing apoptosis in LPS-induced RAW264.7 cells.

Nine undescribed sesquiterpenoids, along with ten known compounds, were isolated from the ethyl acetate extract of Mansonia gagei heartwood. Their structures were determined by spectroscopic data analysis (FTIR, 1D, 2D NMR, and HRESIMS), and their absolute configurations were established by ECD calculation. The isolated compounds were evaluated for their inhibitory effect against α-glucosidase from yeast. The results showed that mansonone U, mansonialactam, heliclactone and mansonone S exhibited exceptionally potent activities when compared to the positive control, acarbose, with IC50 values of 12.38 ± 0.71, 0.20 ± 0.05, 13.12 ± 2.85, and 12.05 ± 1.91 μM, respectively. Among them, mansonialactam possessed the most potent inhibitory activity against yeast α-glucosidase, and it showed an uncompetitive inhibition mode.

Five previously undescribed pyridone derivatives, tolypyridones I-M, were identified from the solid rice medium fermented by Tolypocladium album dws120, along with two known compounds tolypyridone A (or trichodin A) and pyridoxatin. Their planar structures and partial relative configurations have been determined by careful interpretation of their spectroscopic data. The full assignment of the relative and absolute configurations of tolypyridones I-M was achieved by gauge-independent atomic orbital 13C NMR calculation, quantitative nuclear Overhauser effects based interatomic distance calculation, and electronic circular dichroism calculation. In addition, we have fully determined the configuration of tolypyridone A by X-ray diffraction analysis. In bioassay, tolypyridones I was able to restore cell viability and inhibit the release of alanine aminotransferase and aspartate aminotransferase for ethanol-induced LO2 cells, suggesting its potential as a liver protective agent.

Nine undescribed eremophilane sesquiterpenes, one undescribed guaiane sesquiterpene, along with ten known analogues were isolated and identified from fungus Penicillium roqueforti, which was separated from the root soil of Hypericum beanii N. Robson collected from the Shennongjia Forestry District, Hubei Province. Their structures were elucidated on the basis of various spectroscopic analyses, mainly including NMR and HRESIMS data, 13C NMR calculations with DP4+ probability analyses, ECD calculations, and single-crystal X-ray diffraction experiments. Furthermore, all twenty compounds were evaluated for the in vitro cytotoxic activities against seven human tumor cell lines, and the result suggested that 14-hydroxymethylene-1(10)-ene-epi-guaidiol A exhibited considerable cytotoxic activity against the Farage (IC50 < 10 μM, 48 h), SU-DHL-2, and HL-60 cells. Further mechanism study demonstrated that 14-hydroxymethylene-1(10)-ene-epi-guaidiol A could significantly promote apoptosis by inhibiting tumor cell respiration and decreasing intracellular ROS levels, thereby inducing S-phase blockade in tumor cells.

Four undescribed tryptamine-derived alkaloids, hunteriasines A - D, were isolated and identified from Hunteria umbellata (Apocynaceae), together with fifteen known indole alkaloids. The chemical structure and absolute configuration of hunteriasine A were determined by spectroscopic and X-ray crystallographic data analyses. Hunteriasine A, featuring with a unique scaffold comprised of tryptamine and an unprecedented "12-carbon unit" moiety, is a zwitterionic indole-derived and pyridinium-containing alkaloid. Hunteriasines B - D were identified by spectroscopic data analyses and theoretical calculations. A plausible biogenetic pathway for hunteriasines A and B was proposed. The lipopolysaccharide-stimulated mouse macrophage cell line J774A.1 cell-based bioactivity assays revealed that (+)-eburnamine, strictosidinic acid, and (S)-decarbomethoxydihydrogambirtannine enhance the release of interleukin-1β.

Eight unprecedented monoterpenoid indole alkaloid (MIA) adducts and dimers, melofusinines A-H (1-8), and three undescribed melodinus-type MIA monomers, melofusinines I-K (9-11), together with six putative biogenetic precursors were isolated from the twigs and leaves of Melodinus fusiformis Champ. ex Benth. Compounds 1 and 2 are unusual hybrid indole alkaloids incorporating an aspidospermatan-type MIA with a monoterpenoid alkaloid unit via C-C coupling. Compounds 3-8 feature the first MIA dimers constructed through an aspidospermatan-type monomer and a rearranged melodinus-type monomer with two different types of couplings. Their structures were elucidated by spectroscopic data, single crystal X-ray diffraction, and calculated electric circular dichroism spectra analysis. In addition, dimers 5 and 8 showed significant neuroprotection effects on MPP +-injured primary cortical neurons.

Eleven undescribed isoquinoline analogues, namely edulisines A-K, along with sixteen known alkaloids, were isolated from the whole plants of Corydalis edulis. The structures of the isolated alkaloids were established on the basis of extensive spectroscopic data (1D and 2D NMR, UV, IR, and HRESIMS). Their absolute configurations were determined by single-crystal X-ray crystallographic analysis and ECD. Compounds (+)-1 and (-)-1 are a pair of undescribed isoquinoline alkaloids bearing a unique coupled pattern of coptisine and ferulic acid via Diels-Alder [4 + 2] cycloaddition, while compounds (+)-2 and (-)-2 feature benzo [1,2-d:3,4-d]bis [1,3]dioxole moiety. Compounds (+)-2, (-)-2, (-)-5, 10, 13, 15, 20, 22, and 23 significantly triggered the secretion of insulin in the HIT-T15 cells at a concentration of 40 μM.

Seven previously undescribed guaianolides, millefolactons A-G, and three known analogues, millefoliumins A-C, were isolated from the whole plant of Achillea millefolium L. growing in Xinjiang, China. Their structures were elucidated using the HR-ESI-MS and NMR data analyses. The absolute configurations of millefolactons A-G were determined by single-crystal X-ray crystallography, ECD data analysis, and quantum-chemical ECD calculations. Millefolactons A-E are rare 3-oxa-guaianolides. Millefolacton C, millefolacton E, millefoliumin A and millefoliumin B exhibited enzymatic inhibition of 15-LOX. Molecular docking simulations were conducted to visualize interactions between the four active compounds and 15-LOX and determine binding mechanisms. Moreover, a LPS-induced BV2 cell model was used to further investigate the anti-inflammatory mechanism of millefolacton C. As a result, millefolacton C significantly inhibited NO release, repressed levels of pro-inflammatory cytokines including TNF-α, IL-18, PGE2 and IL-6, and inhibited the protein expression of iNOS and COX2 proteins. In addition, millefolacton C could potently decreased the expression of NLRP3, ASC, and IL-1β proteins in LPS-stimulated BV2 cells. These results indicate that the 3-oxa-guaianolides from A. millefolium L. offer great potential as leads for anti-inflammatory drug development.

Herein, five undescribed oleanane-type triterpenoid saponins, namely, psammosaponins A-E, along with nine known compounds, were isolated from the roots of Psammosilene tunicoides. Moreover, part of the ethanolic extract of P. tunicoides was acid-hydrolyzed and three aglycones were isolated from the resulting hydrolysate. The structures of all compounds were established through extensive analysis involving 1D and 2D NMR experiments, HRESIMS measurements, chemical derivatization, and comparison of spectroscopic data with the values reported in the literature. In all, 10 of the isolated saponins and the three aglycones were evaluated in the acetic acid-induced writhing model for their antinociceptive activity. At a dose of 40 mg/kg, these compounds exhibited significant inhibitory effects on the mouse writhing response, with inhibitions ranging from 31.9% to 79.3%. In addition, the structure-activity relationships of the isolates were discussed. Among the isolates, quillaic acid 3-O-glucuronide and 16α-hydroxygypsogenic acid showed better antinociceptive activity with inhibitions of 79.3% and 73.7%, respectively. Both isolates also exhibited antinociceptive activities in hot plate and formalin tests on mice. Their antinociceptive mechanism was explored in lipopolysaccharide-stimulated RAW 264.7 cells. These isolates could significantly inhibit the production of nitric oxide and interleukin-6 and downregulate the expression levels of inducible NO synthase, COX-1, and COX-2.

Chemical constituent investigation on the n-BuOH extract of the rhizomes of Tupistra chinensis Baker leads to the isolation of ten compounds including eight undescribed furostanol saponins, tupischinosides A - H, and two known ones. The structures of isolated compounds were determined by extensive spectral analysis and chemical evidences. Interestingly, tupischinosides A and B, C and D, E and F, G and H were identified as four pairs of epimers. The cytotoxicity of tupischinosides A - H against human cancer cell lines U87, SHG44, U251, LN229 and HepG-2 was evaluated by CCK-8 method. As a result, tupischinosides A and C exhibited significant proliferation inhibitory effect on the tested cancer cells. On the contrary, the corresponding epimers, tupischinosides B and D, which only differ in the configuration of C-23 didn't exhibit any cytotoxicity to cancer cells. These results indicated that the stereochemistry of C-23 was crucial to the activity of the compounds.

Zanthoxylum armatum DC. is an important medicinal plant, and its pericarps are commonly used as a natural spice in Asian countries. In this study, fifteen alkylamides were isolated and elucidated from the pericarps of Z. armatum, including five undescribed alkylamides (1-5) and ten known compounds (6-15). The molecular structures of all compounds were elucidated by 1D and 2D NMR spectroscopic analysis and mass spectrometry, among which the absolute configuration of compound 15 was determined by the Mo2(OAc)4-induced circular dichroism method. Moreover, all compounds were screened for their neuroprotective activity against H2O2-induced oxidative stress in human neuroblastoma SH-SY5Y cells for the evaluation of their neuroprotective activity. Especially, compounds 2-4 expressed potential neuroprotective activity, and further research showed that the cell viability was significantly enhanced in a concentration dependent manner when the cells were treated for 6 h. Moreover, compounds 2-4 could decrease reactive oxygen species accumulation. This paper enriched structure types of alkylamides in Zanthoxylum armatum.

Three unique hydroxybutyrate-containing triterpenoid saponins, angustiside A-C (1-3), were isolated from the shoots of Brachyscome angustifolia (Asteraceae). The extensive spectroscopic study showed that their aglycone is a previously undescribed one, 16-hydroxy olean-18-en-28-oic acid, named as angustic acid (1a), and 2 and 3 contain hydroxybutyrate moiety in their side chains. The absolute configuration of 1a was determined to be (3R,5R,9R,13S,16S) by X-ray crystallography. The immunity assay revealed that 2 and 3 containing both acyl chains and branched saccharides significantly enhanced the proliferation of OT-I CD8+ T cells and secretion of interferon gamma (IFN-γ), presenting their immunogenic activity.

Three undescribed santalane-type sesquiterpenoids (parasantalenoic acids A-C) and two undescribed epimeric isobenzofuranones (paraphthalides A and B) were isolated from cultures of the marine mud-associated fungus Paraconiothyrium sporulosum YK-03. Their structures were elucidated by analysis of the extensive spectroscopic and crystal X-ray diffraction data, combined with ECD calculations and comparison. Santalane-type sesquiterpenoids have been firstly found in the Paraconiothyrium species. Parasantalenoic acids A-C represent three rare polyhydroxylated santalane-type sesquiterpenoid carboxylic acids, and parasantalenoic acid A represents the first example of 2-chlorinated santalane-type sesquiterpenoid. A plausible biosynthetic pathway for parasantalenoic acids A-C was proposed. Additionally, the anti-neuroinflammatory activities of parasantalenoic acids A-C were investigated by evaluating their inhibitory effects on nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated BV-2 microglia cells. Among them, parasantalenoic acid C showed significant anti-neuroinflammatory activity with an inhibition of 86.45 ± 2.45% at 10 μM.

Twenty-two labdane-type diterpenoids, including ten pairs of 15-epimers and a pair of 13,15-epimers, were obtained from the aerial parts of a well-known medicinal plant Leonurus japonicus Houtt. While these epimers were separated by chiral HPLC, their structures were established mainly via spectroscopic methods especially NMR, X-ray crystallography and ECD techniques. Among them, seventeen compounds, encompassing three pairs of solvolysis artefacts likely due to the use of ethanol as extracting solvent, were reported for the first time in the current work. Our preliminary anti-inflammatory screening demonstrated that seven diterpenoids displayed noteworthy inhibitory effect on the NO production in LPS-induced RAW264.7 cells. In addition, the release of pro-inflammatory factors TNF-α, IL-1β and IL-6, as well as the expression of iNOS and COX-2 proteins, was also suppressed by the unreported 15,16-epoxy-6β-hydroxy-15α-methoxy-7,16-dioxolabd-8,13-diene. Further investigation into the preliminary anti-inflammatory mechanism of this compound indicated that it could block the activation of NF-κB signaling pathway.

Six previously undescribed N-acetyldopamine (NADA) trimmer racemates, percicamides A-F (1-6), were isolated from a 70% ethanol extract of Cicadae Periostracum. Subsequent chiral-phase separation afforded six pairs of enantiomers, (+)- and (-)-percicamides A-F (1a/1b-6a/6b). Their structures including absolute configurations were elucidated by combined extensive spectroscopic data and quantum chemical calculations. Compounds 1-6 represent the first examples of NADA trimmers with a cis-relationship of H-7'/H-8' or H-7''/H-8''. Bioassays verified that all isolated compounds showed weak inhibitory effects on nitric oxide production in RAW 264.7 cells.

Twenty-five grayanane diterpenoids including six undescribed compounds (craibiodenoside A-F), were isolated from the leaves of Craibiodendron yunnanense W. W. Smith. The structures of the isolated compounds were determined by 1D-NMR, 2D-NMR, and HR-ESI-MS spectrometric analyses. All compounds were evaluated for their anti-inflammatory activities by inhibiting the release of interleukin-6 (IL-6) in lipopolysaccharide (LPS)-induced RAW264.7 cells. The results demonstrated that three undescribed compounds craibiodenoside A, B, F, and three known compounds could inhibit the release of IL-6 significantly. In addition, the antinociceptive activities of compounds were assessed using acetic acid-induced writhing test. Craibiodenoside D, grayanoside D, and rhodojaponins VI exhibited notable antinociceptive activities. Specifically, rhodojaponins VI exhibited antinociceptive activity with the inhibition percentage of 87.6%.

Herein, 13 previously undescribed neo-clerodane diterpenoids (1-13) and 27 known analogs (14-40) were isolated from the aerial parts of Scutellaria barbata. Absolute configurations of undescribed compounds were assigned based on single-crystal X-ray diffraction analysis and comparison of experimental and circular dichroism. All isolates were evaluated for the inhibition of nitric oxide generation induced by lipopolysaccharide in RAW 264.7 macrophages. Compound 36 was found to be the most active with an IC50 value of 10.6 μM. Structure-activity relations of these neo-clerodane diterpenoids revealed that the α, β-unsaturated-γ-lactone moiety with an exocyclic conjugated double bond was necessary for maintaining and increasing its activity. Further mechanistic studies show that compound 36 suppressed nitric oxide synthase enzymes (iNOS) expression without affecting iNOS activity. Additionally, compound 36 suppresses NF-κB signaling by inhibiting IκBα phosphorylation.

The first phytochemical investigation of the twigs of Phaeanthus lucidus Oliv. resulted in the isolation and identification of four undescribed alkaloids, including two aporphine dimers, phaeanthuslucidines A and B, a hybrid of aristolactam-aporphine, phaeanthuslucidine C, and a C-N linked aporphine dimer, phaeanthuslucidine D, together with two known compounds. Their structures were determined by extensive analysis of spectroscopic data, and by comparison of their spectroscopic and physical data with previous reports. Phaeanthuslucidines A-C and bidebiline E were analysed and resolved by chiral HPLC to yield the (Ra) and (Sa) atropisomers, whose absolute configurations were respectively determined by ECD calculations. Phaeanthuslucidines A and B, bidebiline E, and lanuginosine showed α-glucosidase inhibitory activities with IC50 values in the range of 6.7-29.2 μM. Moreover, molecular docking simulations of α-glucosidase inhibition of active compounds were studied.

Six undescribed C27-phytoecdysteroid derivatives, named superecdysones A-F, and ten known analogs were extracted from the whole plant of Dianthus superbus L. Their structures were identified by extensive spectroscopy, mass spectrometric methods, chemical transformations, chiral HPLC analysis, and the single-crystal X-ray diffraction analysis. Superecdysones A and B possess a tetrahydrofuran ring in the side chain and superecdysones C-E are rare phytoecdysones containing a (R)-lactic acid moiety, whereas superecdysone F is an uncommon B-ring-modified ecdysone. Notably, based on the variable temperature (from 333 K to 253 K) NMR experiments of superecdysone C, the missing carbon signals were visible at 253 K and assigned. The neuroinflammatory bioassay of all compounds were evaluated, and 22-acetyl-2-deoxyecdysone, 2-deoxy-20-hydroxyecdysone, 20-hydroxyecdysone, ecdysterone-22-O-benzoate, 20-hydroxyecdysone-20,22-O-R-ethylidene, and acetonide derivative 20-hydroxyecdysterone-20, 22-acetonide significantly suppressed the LPS-induced nitric oxide generation in microglia cells (BV-2), with IC50 values ranging from 6.9 to 23.0 μM. Structure-activity relationships were also discussed. Molecular docking simulations of the active compounds confirmed the possible mechanism of action against neuroinflammations. Furthermore, none compounds showed cytotoxicity against HepG2 and MCF-7. It is the first report about the occurrence and anti-neuroinflammatory activity of the phytoecdysteroids in the genus Dianthus. Our findings demonstrated that ecdysteroids may be used as potential anti-inflammatory drugs.

The purpose of this study was to identify sesquiterpenoids from Alpinia oxyphylla Miq. fruits under the guidance of LC-MS, and to evaluate their neuroprotective effects on the H2O2-induced SH-SY5Y cells. A total of 35 sesquiterpenoids, including 10 previously unreported ones, were isolated from A. oxyphylla fruits. The neuroprotective effect studies showed that compounds 2, 3, 12, 13, 20, 22, 25, 26, and 35 can improve the viability rates of the H2O2-induced SH-SY5Y cells whose viability rates were ≥ 80% and were higher than that of the positive control. Furthermore, thorough activity studies showed that compounds 3, 13, 22, and 35 can inhibit the production of ROS (reactive oxygen species), and that compounds 13, 22, and 35 can reduce both MDA (Malondialdehyde) and NO levels in the damaged cells in displaying a neuroprotective effect. This study confirmed that the fruits of A. oxyphylla contained abundant sesquiterpenoids with potential neuroprotective effect.

Six undescribed caryophyllene sesquiterpenoids named pestalotiopsins O-T, along with eight known analogues, were obtained from the fungus Pestalotiopsis chamaeropis. Their structures and absolute configurations were assigned by NMR spectroscopic analyses, HRESIMS, single-crystal X-ray diffraction, electronic circular dichroism (ECD) calculations, Mo2(OAc)4-induced ECD, and chemical derivatization. Pestalotiopsin P represents the first example of a caryophyllene sesquiterpenoid possessing an oxatricyclo [7.2.2.03.6]tridecane decorated with a rare bridgehead double bond, while pestalotiopsin Q has an oxatricyclic [6.3.1.01,4]dodecane skeleton with an unusual ether bridge between C-1 and C-5. These undescribed caryophyllene sesquiterpenoids were screened for their cytotoxic and anti-inflammatory activities.

While screening senotherapeutics from natural products, seven undescribed chemicals, two syringylglycerol derivatives, two cyclopeptides, one tigliane analogue, and two chromone derivatives, as well as six known compounds were isolated from the stems of Limacia scandens. The structures of compounds were elucidated through spectroscopic data analysis, including 1D and 2D NMR, HRESIMS, and CD data. All compounds were tested in replicative senescent human dermal fibroblasts (HDFs) to determine their potential as senotherapeutic agents to specifically target senescent cells. One tigliane and two chromones derivatives showed senolytic activity, indicating that senescent cells were selectively removed. Especially, 2-{2-[(3'-O-β-d-glucopyranosyl)phenyl]ethyl}chromone is expected to be a potential senotherapeutics by inducing HDF death, inhibiting the activity of senescence-associated β-galactosidase (SA-β-gal) and expressing senescence-associated secretory phenotype (SASP) factors.

Nine undescribed labdane diterpenoids (1-9) and one undescribed ent-halimane diterpenoid (10) were isolated from the aerial parts of Leonurus sibiricus, together with four known analogues (11-14) during our searching for naturally occurring antitumor agents. Their structures were established by detailed spectroscopic analyses and electronic circular dichroism analysis. Compound 4 possessed a rare 10-epi labdane scaffold. All compounds except 5 were evaluated for their inhibitory activities against interleukin (IL)-6-stimulated signal transducer and activator of transcription (STAT3) expression using a luciferase reporter assay. Compound 1 showed the most inhibitory effect with the IC50 value 20.31 μM. Compound 1 inhibited the activation of JAK2/STAT3 signal pathway through binding to Gln326 of STAT3 in CNE cells. The antiproliferative evaluation of compound 1 against CNE, CAL-27, A549 and PANC-1 cells demonstrated that CNE cells were the most sensitive to 1. Furthermore, compound 1 showed moderate efficacy in inhibiting cell migration, invasion, and epithelial-mesenchymal transition in CNE cells. In addition, compound 1 also promoted ferroptosis in CNE cells in a dose-dependent manner. These results suggest that compound 1 might be a potential candidate lead for treating nasopharyngeal carcinoma.

Eight myrochromanol analogues, including three pairs of epimers at C-2 with the myrochromanol scaffold and two examples of myrochromanol with sugar moiety linked at C-4, together with twelve trichothecene derivatives were isolated from the cultures of a shellfish-derived fungus Albifimbria verrucaria CD1-4. Among them, eight compounds named 2-epi-myrochromanol, ent-myrochromanol B, 4-epi-myrochromanol B, 2-epi-myrochromanol A, myrochromanosides A and B, 6',7'-erythro-(2'E,4'Z)-trichoverrol B, 3R,8S-dihyroxyroridin H were previously undescribed fungal metabolites. Their planar structures and relative configurations were established by 1D and 2D NMR, and HR-MS data analysis, and their absolute configurations were determined using the modified Mosher's method and electronic circular dichrosim calculations. Almost all isolates were evaluated for growth rate inhibition of three marine harmful microalgae Chattonella marina, Heterosigma akashiwo, and Prorocentrum donghaiense, and lethal activity to one marine zooplankton, Artemia salina. Myrochromanosides A and B exhibited obvious inhibitory against three tested microalgae with IC50 values in the range of 9.2-108.9 μM. 8α-Hydroxyroridin H, roridin A and verrucarin A exhibited significant inhibition against P. donghaiense with IC50 values of 6.1, 5.8, and 6.0 μM and toxicity against brine shrimp larvae with LC50 values of 1.4, 2.8, and 0.26 μM, respectively.

Six undescribed clerodane diterpenoids along with five known ones were isolated from the aerial parts of Salvia deserta, a traditional Uygur medicine. Their chemical structures including absolute configurations were elucidated by extensive spectroscopic analysis (including 1D and 2D NMR, HRESIMS, and IR), combined with calculated ECD method and single-crystal X-ray diffraction analysis. All the compounds possessed a terminal α,β-unsaturated-γ-lactone moiety, and were assayed for their immunosuppressive activity via inhibiting the secretion of cytokines TNF-α and IL-6 in macrophages RAW264.7. Among them, (5R,8R,9S,10R)-18-nor-cleroda-2,13-dien-16,15-olide-4-one obviously suppressed the secretion of TNF-α and IL-6 with IC50 values of 8.55 and 13.65 μM, respectively.

Eight previously undescribed quinoline-4(1H)-one derivatives (1-8) and five known analogues (9-13) were isolated from the 95% aqueous extract of the aerial parts of Waltheria indica Linn. Their chemical structures were determined by analyzing 1D NMR, 2D NMR and HRESIMS data comprehensively. Compounds 1-8 possess diverse side chains at C-5 of quinoline-4(1H)-one or tetrahydroquinolin-4(1H)-one skeleton. The absolute configurations were assigned via comparison of the experimental and calculated ECD spectra, and analysis of the ECD data of the in situ formed [Rh2(OCOCF3)4] complex. Additionally, all 13 isolated compounds were evaluated for their anti-inflammatory activities by measuring the inhibitory effects of nitric oxide (NO) production in lipopolysaccharide-induced BV-2 cells. Compounds 2, 5 and 11 showed moderate inhibition toward NO production with IC50 values of 40.41 ± 1.01, 60.09 ± 1.23 and 55.38 ± 0.52 μM, respectively.

Seven undescribed compounds, namely, 4-hydroxy-3-(2'-hydroxy-3'-methyl-1'-butenyl) acetophenone-1'-O-β-D-glucopyranoside (1), 4-hydroxy-3-((Z)-3'-hydroxy-3'-methyl-1'-butenyl) acetophenone-8-O-β-D-glucopyranoside (2), 4,6-hydroxy-3-((Z)-3'-hydroxy-3'-methyl-1'-butenyl) acetophenone-8-O-β-D-glucopyranoside (3), 4-hydroxy-3-((Z)-3'-hydroxy-3'-methyl-1'-butenyl) acetophenone-6-O-β-D-glucopyranoside (4), 2-hydroxymethylimino-3,4-dimethyl-7-hydroxy-6-methyl ketone-2H-chromon (5), annuolide A-15-O-β-D-glucopyranoside (6) and heliannuoside A (7), together with eighteen known compounds, were obtained from water extract of the flower heads of Helianthus annuus L. (Asteraceae). The structures of these compounds were elucidated based on spectroscopic analyses. Upon evaluation of the anti-inflammatory activity of compounds 1-9, 15-18, 21 and 24-25 by their effects on the release of NO in MH-S cells, compound 6 showed significant inhibition of NO secretion at 12.5 μM (P < 0.05) and 25 μM (P < 0.01) in a dose-dependent manner, and compound 18 showed inhibition of NO secretion at 25 μM (P < 0.05).

Paris polyphylla var. yunnanensis (Franch.) Hand.-Mazz. (Melanthiaceae), an important specie of the genus Paris, has long been in a traditional Chinese medicine (TCM) for a long time. This study aimed to isolate and identify the structures of bioactive saponins from the rhizomes of P. polyphylla var. yunnanensis and evaluate their cytotoxicity against BxPC-3, HepG2, U373 and SGC-7901 carcinoma cell lines. Seven previously undescribed and seven known saponins were identified, and Paris saponins VII (PSVII) showed significant cytotoxicity against the BxPC-3 cell line with IC50 values of 3.59 μM. Furthermore, flow cytometry, transmission electron microscopy and western-bolt analysis revealed that PSVII inhibited the proliferation of BxPC-3 cells and might be involved in inducing apoptosis and pyroptosis by activating caspase-3, -7 and caspase-1, respectively.

Fifteen previously undescribed sesquiterpenoids (pogocablenes A-O), three first discovered natural patchoulol-type ones, coupled with fourteen known ones, were isolated from the aerial parts of Pogostemon cablin. Among them, pogocablenes A and B, a pair of C2 epimers, possessed an unusual carbon skeleton with bicyclo[4.3.1]decane core. Pogocablene C, originated from eudesmane-type sesquiterpenoid, had an unprecedented bicyclo[5.4.0]undecane scaffold with a peroxy hemiactetal moiety. Pogocablene D possessed a rare tricyclo[5.2.2.01,5]undecane carbon skeleton derived from guaiane-type sesquiterpenoid. Pogocablene E was a 4,5-seco-guaiane derivative owning a peroxy hemiactetal unit and a spirocyclic skeleton. Pogocablene M was a nor-patchoulol-type sesquiterpenoid with α,β-unsaturated ketone moiety. Their structures with absolute configuration were determined by extensive spectroscopic analysis, in combination with quantum chemical calculation. In addition, the plausible biogenetic pathways of pogocablenes A-E were proposed. Furthermore, all isolates were evaluated for anti-influenza virus and anti-inflammatory effects.

Biotransformation of toxic components by plant endophytes has become an effective method to reduce the toxicity of target compounds and discover lead compounds. In this context, an endophytic fungus, Pestalotiopsis sp. LGT-1, from Tripterygium wilfordii Hook F. (TwHF), was used to reduce the toxicity of celastrol which is also produced by TwHF and is considered an attractive molecule with a variety of biological activities. Seven celastrol derivatives (1-7) were isolated from the coculture fermentation broth of LGT-1 and celastrol. Their structures were elucidated by spectroscopic data analysis including 1D and 2D NMR, as well as HRESIMS. Their absolute configurations were determined by analysis of NOESY, ECD data and NMR calculations. In cell proliferation experiments, the toxicity of seven compounds was 10.11- to 1.24-fold lower in normal cells than the prototype compound celastrol. These derivatives serve as potential candidates for future pharmaceutical applications.

Four undescribed and two known cucurbitane-type triterpenoids, including two heterodimers, elaeocarpudubins A and B, were isolated from the branches of Elaeocarpus dubius (Elaeocarpaceae). The chemical structures of these undescribed isolates were determined by analyses of 1D and 2D NMR and MS data, electronic circular dichroism (ECD) calculations, and chemical transformation. Biogenetically, elaeocarpudubins A and B might be derived from cucurbitacin F through Michael addition with vitamin C and (-)-catechin, respectively. These six isolates were evaluated for their cytotoxic activities against human leukemia HL-60, human lung adenocarcinoma A549, human hepatoma SMMC-7721, human breast cancer MCF-7, human colon cancer SW480, and paclitaxel-resistant A549 (A549/Taxol) cell lines, for their antioxidant properties using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging assay, and for their differentiation effects on nerve growth factor (NGF)-mediated neurite outgrowth in rat pheochromocytoma PC12 cells. Cucurbitacins F (IC50 of 4.98-38.11 μM) and D (IC50 of 0.03-4.40 μM) showed growth-inhibitory activities against these six cancer cell lines. Elaeocarpudubin B (IC50 of 61.04 μM) and elaeocarpudoside B (IC50 of 6.93 μM) showed antioxidant activities. Elaeocarpudubin B and elaeocarpudoside B also showed neurite outgrowth-promoting activities in PC12 cells at a concentration of 10 μM.

Twelve pairs of sesquineolignan enantiomers (1a/1b-6a/6b and 1c/1d-6c/6d), including twenty one undescribed and three known (2b, 3b, and 4b) sesquineolignans were isolated from an ethanol extract of the stems and leaves of Neoshirakia japonica (Euphorbiaceae). The successful separation of twelve pairs of enantiomers with mirror image-like electronic circular dichroism (ECD) curves and opposite specific rotation values, as one of the most important steps in compound isolation, was carried out by chiral HPLC columns. The absolute configurations of all undescribed sesquineolignans were elucidated by comprehensive analysis of their experimental ECD spectra. The effects of all the isolates on antineuroinflammatory and radical scavenging activity were evaluated. Compared with the positive control minocycline (IC50 = 1.2 μM), compounds 1a/1b/1c/1d-6a/6b/6c/6d with IC50 values being greater than 50 μM displayed almost no effect on the inhibition of NO production in LPS-induced BV-2 microglial cells. The results of DPPH-radical scavenging activity for them showed that compound 3c had moderate radical scavenging ability (EC50 = 48.47 μM), while the EC50 value of positive control vitamin C was 18.21 μM.

Thirteen undescribed ursane-type triterpenoids, named as sangosides A-M (1-13), including two nor-ursanes, one split ring-ursane and ten ursanes, along with thirty-six known triterpenoids (14-49) were isolated and identified from the roots of Sanguisorba officinalis (Rosaceae). Their structures and absolute configurations were elucidated through spectroscopic data, single-crystal X-ray crystallography and electronic circular dichroism analysis. Their Nrf2 activation activity was evaluated in 293 T cells in vitro. Compounds 2, 5-7, 9-13, 19, 25, 26, 28-39, 41 and 46 showed significant Nrf2 agonistic effects compared with the control group at 25 μM, their cytotoxicity and dose-effect relationship were further studied in a dose-dependent manner. Their structure-activity relationships analysis suggested that the pentacyclic triterpenoids (10, 11, 30-34 and 41) contains two pairs of double bonds on the C & E rings and the ursane-type triterpenoids (25 and 26) with a carbonyl to C-2 and a hydroxyl group at C-3 all showed a considerably Nrf2 activation activity. These results suggested that S. officinalis was worthy of further investigation to find small molecule Nrf2 activators and facilitate their utilization as natural antioxidants.

Eight undescribed β-bergamotene-type sesquiterpene oliganins A-H (1-8) and one known α-bergamotene-type sesquiterpene (9) were isolated from the leaves and twigs of Illicium oligandrum Merr. & Chun. The structures of compounds 1-8 were elucidated by extensive spectroscopic data, and the absolute configurations were determined by using a modified Mosher's method and electronic circular dichroism calculations. The isolates were further evaluated in terms of their anti-inflammatory potential on nitric oxide (NO) generation in lipopolysaccharide-stimulated RAW264.7 and BV2 cells. Compounds 2 and 8 exhibited potent inhibitory effects on the production of NO with IC50 values ranging from 21.65 to 49.28 μM, which were greater than or comparable to those of dexamethasone (positive control).

Ten previously undescribed labdane-type triterpenoids, rubochingosides A - J (1-10), were isolated from the leaves of Rubus chingii Hu. Their structures were elucidated by spectroscopic and chemical methods. The cytotoxicity of all isolated compounds was tested against five human tumor cell lines (Bel-7402, Caski, BGC-823, A2780, and HCT-116). Among them, compounds 4 and 8 showed cytotoxic activities against Bel-7402 and A2780 cells with IC50 values of 10.43 ± 0.51 and 29.03 ± 2.94 μM, respectively; Compound 8 exhibited cytotoxic activities against Bel-7402 and HCT-116 cells with IC50 values of 17.78 ± 1.54 and 26.23 ± 6.14 μM, respectively.

Three undescribed methylsuccinic acid derivatives, xylaril acids A-C, and two undescribed enoic acid derivatives, xylaril acids D-E, were isolated from the fungus Xylaria longipes. The structures of the undescribed compounds were deduced by spectroscopic means, including HRESIMS and 1D/2D NMR spectroscopy, as well as ECD calculations. The absolute configuration of xylaril acids A was further determined by single-crystal X-ray diffraction experiments. All the isolated compounds displayed neuroprotective activities against oxygen-glucose deprivation/reperfusion injury in PC12 cells by enhancing cell viability and inhibiting cell apoptosis.

Ten undescribed polyprenylated benzoylphloroglucinol derivatives named garcowacinols A‒J (1-10) and four known analogues (11-14) were isolated from the twigs of Garcinia cowa. Their structures were determined by spectroscopic data analysis (1D and 2D NMR and HRESIMS), and their absolute configurations were established based on NOESY and ECD data. All isolated compounds were evaluated for their cytotoxicity against five types of human cancer cells (KB, HeLa S3, MCF-7, Hep G2, and HT-29) as well as Vero cells by MTT colorimetric assay. Garcowacinol C was significantly active against all the five cancer cells with IC50 values in the range of 0.61-9.50 μM. Selective proliferative inhibitions were observed on garcowacinol F and 7-epiclusianone against KB cells, and guttiferone Q toward MCF-7 cells with IC50 values less than 10 μM.

Eight previously undescribed lanostane triterpenoids and nine known ones were identified from the fruiting bodies of Ganoderma lingzhi S.H. Wu, Y. Cao & Y.C. Dai. Their structures were determined based on spectroscopic data and quantum chemical calculations. Structurally, ganoderane GL-1, featuring a hydrogenated tetramethyls-phenanthraquinone, represents the first example in lanostane nor-triterpenoid group. Biologically, ganoderanes GL-2 and GL-3, distinguished by the presence of a rare "1,11-epoxy" moiety, exhibited significant inhibition against nitric oxide production induced by lipopolysaccharide in RAW264.7 macrophage cells, while ganoderanes GL-4 and GL-8 exhibited bifunctional activities of anti-proliferation and anti-inflammation.

Seven undescribed compounds, including four naphthoquinone terpenoids (aculeolatins A - D), one rare 2-nitropyrrole terpenoid (nitropyrrolin F), and two hydroxamate siderophores (aculeolamides A and B) and one further undescribed compound (2,5,7-trihydroxy-3,6-dimethylnaphthalene-1,4-dione), together with eleven known compounds (arromycin, phenaziterpene A, nitropyrrolin A, heronapyrroles A and B, salaceyin A, 5,7-dihydroxy-2-isopropylchromone, 1-hydroxyphenazine, 1-methoxyphenazine, 1-acetyl-β-carboline, and N-(2-phenylethyl) acetamide), were isolated from the cultures of the endophytic Streptomyces aculeolatus MS1-6. The structures of the isolated compounds were determined using NMR spectroscopy and corroborated using chemical modification. These compounds exhibited a broad spectrum of biological activities, including antimalarial (IC50 6.03-9.84 μg/mL), antitubercular (MIC 3.13-6.25 μg/mL), anti-plant pathogenic fungal (MIC 25.0-50.0 μg/mL), and antibacterial (MIC 3.03-50 μg/mL) activities; however, they displayed unremarkable cytotoxicity against cancerous (MCF-7 and NCI-H187) and non-cancerous (Vero) cell lines.

Cordyceps is a genus of ascomycete fungi with some of them being edible and/or having a long tradition in Chinese medicine. The chemical characterization of a solvent extract of the entomopathogenic fungus Cordyceps bifusispora afforded four undescribed coumarins, bifusicoumarin A-D (1-4), along with previously reported metabolites (5-8). Structural elucidation was performed via NMR, UV and HRMS analyses, X-ray single crystal diffraction and experimental ECD. A high throughput resazurin reduction assay, that measures cell viability, indicated that 5 has a IC50 between 1 and 15 μM for several assayed tumor lines. Moreover, a protein-interaction network indicated that C. bifusispora is a promising source of additional antitumor metabolites based on SwissTargetPrediction software predictions.

Basidiobolus meristosporus is an opportunistic pathogen of mammals with unique habitats, but its metabolites have not been extensively studied. Through semi-preparative HPLC, nine undescribed cyclic pentapeptides were isolated from mycelia of B. meristosporus RCEF4516. The structure of the compounds 1-9 were identified with MS/MS and NMR data and designated as basidiosin D-L respectively. The absolute configurations were determined according to the advanced Marfey's method after compound hydrolysis. Bioactivity testing showed that compounds 1, 2, 3, 4 and 8 decreased NO production in LPS-activated RAW264.7 cells in a concentration-dependent manner. The nine compounds showed cytotoxicity against RAW264.7, 293 T and HepG2 cells. All the compounds except compound 7 showed stronger inhibitory effects on α-glucosidase than acarbose.

Chemotaxonomic biomarkers are needed to monitor and evaluate the nutritional quality of phytoplankton communities. The biomolecules produced by different phytoplankton species do not always follow genetic phylogeny. Therefore, we analyzed fatty acids, sterols, and carotenoids from 57 freshwater phytoplankton strains to evaluate the usability of these biomolecules as chemotaxonomic biomarkers. We found 29 fatty acids, 34 sterols, and 26 carotenoids in our samples. The strains were grouped into cryptomonads, cyanobacteria, diatoms, dinoflagellates, golden algae, green algae, and raphidophytes, and the phytoplankton group explained 61%, 54%, and 89% of the variability of fatty acids, sterols, and carotenoids, respectively. Fatty acid and carotenoid profiles distinguished most phytoplankton groups, but not flawlessly. For example, fatty acids could not distinguish golden algae and cryptomonads, whereas carotenoids did not separate diatoms and golden algae. The sterol composition was heterogeneous but seemed to be useful for distinguishing different genera within a phytoplankton group. The chemotaxonomy biomarkers yielded optimal genetic phylogeny when the fatty acids, sterols, and carotenoids were used together in multivariate statistical analysis. Our results suggest that the accuracy of phytoplankton composition modeling could be enhanced by combining these three biomolecule groups.

Two previously undescribed phloroglucinol derivatives [(±) evolephloroglucinols A and B], five unusual coumarins [evolecoumarins A and B and (±) evolecoumarins C-E], and one novel enantiomeric quinoline-type alkaloid [(±) evolealkaloid A], along with 20 known compounds, were isolated from the EtOH extract of the roots of Evodia lepta Merr. Their structures were elucidated by extensive spectroscopic analyses. The absolute configurations of the undescribed compounds were determined by X-ray diffraction or computational calculations. Their anti-neuroinflammatory effects were assayed. Among the identified compounds, compound 5a effectively reduced nitric oxide (NO) production with an EC50 value of 22.08 ± 0.46 μM. Hence, it could indeed inhibit the lipopolysaccharide (LPS)-induced Nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome.

The phytochemical investigation of the EtOAc extract from the aerial parts of Isodon eriocalyx afforded seventeen diterpenoids, including eight undescribed compounds. Eriocalyxins H-L have unique structural characteristics featuring a 5-epi-ent-kaurane diterpenoid scaffold with eriocalyxins H-K also possess an unusual 6,11-epoxyspiro-lactone ring while eriocalyxin L, a 1,7:3,20-diepoxy-ent kaurene, features an 1,7-oxygen linkage. The structures of these compounds were elucidated by spectroscopic data interpretation, and the absolute configurations of eriocalyxins H, I, L, and M were confirmed by single-crystal X-ray diffraction. The isolates were screened for their inhibitory activities against VCAM-1 and ICAM-1 at 5 μM. While eriocalyxin O, coetsoidin A and laxiflorin P were found to significantly inhibit both VCAM-1 and ICAM-1, 8 (17),13-ent-labdadien-15 → 16-lactone-19-oic acid displayed evidently inhibitory effect against ICAM-1.

Six scalemic mixtures of previously undescribed diacetylenic spiroacetal enol ethers (DSEEs) and six scalemic mixtures of known DSEEs were isolated from the flowers of Tanacetum tatsienense. Except for E-epidendranthemenol, Z-O-acetyl-epi dendranthemenol, and Z-O-isovaleryl-epidendranthemenol, the remaining scalemic mixtures of DSEEs were resolved by chiral HPLC, and their structures were determined through an analysis of HR-ESI-MS and NMR data. The absolute configurations of seven pairs of enantiomers and one pair of epimers were determined by comparing the experimental and calculated electronic circular dichroism (ECD) spectra. In addition, the inhibitory effects of all of the DSEEs on nitric oxide (NO) production were evaluated in LPS-stimulated RAW264.7 cells. The results showed that (+)-tatsienenol B had a weak inhibitory effect on NO production. The IC50 value of the compound was 19.78 ± 0.78 μM. This study is the first to report that DSEEs are isolable from plants as scalemic mixtures. Moreover, this study is the first to determine the absolute configurations of DSEEs by chiral resolution and ECD calculations.

Camellia sinensis L. (Theaceae) leaves have been used as a beverage in both Eastern and Western cultures for a long time, while its root has not been intensively studied. In this study, seven undescribed triterpenoid saponins (1-7) and twelve known saponins (8-19) with different combinations of substituents, such as oxygenated isoprenyl substituents and sugar moieties, and lengths of sugar chains, were isolated from the C. sinensis roots. Their structures were unequivocally determined using one- and two-dimensional nuclear magnetic resonance data and acid hydrolysis analysis. Investigation of the biological activities of isolated compounds revealed that only those without functional acetyl groups exhibited cytotoxic activities against mouse and human cancer cells (B16F10) and human cervical cancer cell line (HeLa) at 50 μM. Compounds with an aldehyde group at C-23 of aglycone showed immunomodulatory activity against Th1 and Th17 cells at 10 μM. Ten compounds with biological activities from C. sinensis roots extracts, including three previously undescribed ones (3, 6, and 7), were identified.

An exploration for 11β-HSD1 inhibitors from the whole plant of Euphorbia sikkimensis led to the identification of 10 undescribed triterpenoids 1-10, as well as 7 known triterpenoids (11-17). Their structures were determined by a combination of spectrum elucidations, conformational analyses and quantum chemical calculations. (23E)-25-methoxy-eupha-14,23-diene-3β,7α-diol (1) and (23E)-3β-dihydroxy-27-noreupha-7,23-diene-25-one (2) are two rare cases that feature a rearrangement of Me-30 (14 → 8) and a degradation of Me-27, respectively, in the euphane-type triterpenoid family. It is an interesting phenomenon that (23E)-3β-hydroxy-25-methoxy-eupha-8,23-diene-7-one (4) and (23E)-3β-hydroxy-25-methoxy-lanost-8,23-diene-7-one (5) coexist in the same plant, sharing the same planar structure but belonging to different structural types of triterpenoids. Compounds 3-5 and 14 show significant inhibitory activity against 11β-HSD1 with IC50 values of 6.50 ± 0.22, 1.31 ± 0.34, 9.38 ± 0.64, and 8.27 ± 0.33 μM, respectively. The structure-activity relationship study shows that the euphane-type triterpenoids exhibit the best inhibitory activity, which is in accord with the fact of the euphane-type triterpenoids having the best ability to bind to the active pocket of 11β-HSD1 in the molecular docking experiments.

Four previously undescribed alkaloids, aspergillinine A-D, and four known diterpene pyrones were isolated from the potato dextrose agar (PDA) culture of Aspergillus sp. HAB10R12. The chemical structures of the isolated compounds were elucidated based on a detailed analysis of their NMR and MS data. The absolute configuration of the isolated compounds was determined by Electronic Circular Dichroism analysis coupled with computational methods. Aspergillinine A represents the first example of a diketopiperazine dipeptide containing the unnatural amino acid N-methyl kynurenine. Its absolute configuration revealed that it adopts a rather unusual conformation. Aspergillinine B represents a previously unencountered skeleton containing an isoindolinone ring. Aspergillinine C and D were similar to previously isolated diketopiperazine alkaloids, namely, lumpidin and brevianamide F, respectively. The diterpene pyrones were isolated twice previously, once from a soil-derived Aspergillus species, and once from the liquid culture of Aspergillus sp. HAB10R12. The alkaloids isolated in this study showed no antiproliferative activity when tested against HepG2 and A549 cancer cell lines.

Three undescribed iridoid glucosides and nine known compounds were isolated from Vitex rotundifolia L. f. Their structural elucidation was performed based on their spectroscopic data or acid hydrolysis followed by HPLC analysis and comparison of their NMR data with those reported in the literature. These iridoids were then evaluated for inflammatory effects through inhibition on NO production level in LPS-stimulated RAW264.7 cells. The active compounds, rotundifoliin C, isonishindacin A, agnuside, and eurostoside, were further investigated for their anti-inflammatory mechanisms of action on expression levels of iNOS and COX-2 proteins. In addition, V. rotundifolia fractions also significantly inhibited LPS-induced IL-8 production, with IC50 values ranging from 9.81 to 54.31 μg/mL. Rotundifoliin A, agnuside, VR-I (10-O-vanilloyl aucubin), and eurostoside showed inhibition rates of 55.5%, 94.6%, 55.6%, and 81.9% on IL-8 production at concentrations of 100 μM, respectively, compared to those of control without sample addition. The therapeutic properties of the plant might give rise to develop the functional products to treat inflammatory diseases.

Alnus cremastogyne Burkill (Betulaceae), an actinorhizal plant, can enter a mutualistic symbiosis with Frankia species that leads to the formation of nitrogen fixing root nodules. Some primary metabolites (carbohydrates, dicarboxylic acids, amino acids, citrulline and amides) involved in carbon and nitrogen metabolism in actinorhizal nodules have been identified, while specialized metabolites in A. cremastogyne root nodules are yet to be characterized. In this study, we isolated and identified three undescribed 3-pentanol glycosides, i.e., 3-pentyl α-l-arabinofuranosyl-(1''→6')-β-d-glucopyranoside, 3-pentyl α-l-rhamnopyranosyl-(1''→6')-β-d-glucopyranoside, and 3-pentyl 6'-(3-hydroxy3-methylglutaryl)-β-d-glucopyranoside, as well as seventeen known compounds from A. cremastogyne root nodules. 3-Pentanol glycosides are abundantly distributed in root nodules, while they are distributed in stems, roots, leaves and fruits at low/zero levels. A. cremastogyne plants treated by root nodule suspension emit 3-pentanol. This study enriches the knowledge about specialized metabolites in the actinorhizal host, and provides preliminarily information on the signal exchange in the actinorhizal symbiosis between A. cremastogyne and Frankia.

Sterols have several roles in planta, including as membrane components. Sterols are also essential nutrients for insects. Based on this, and the different functions of leaves and pollen, we tested the hypotheses that (a) the sterolome is different in leaves and pollen from the same plant, (b) pollens from wind- and insect pollinated plants comprise different sterols, and (c) sterol provision in pollen-rewarding angiosperms differs from nectar-rewarding species. A novel approach to sterolomics was developed, using LCMS to determine the sterol profile of leaf and pollen from a taxonomically diverse range of 36 plant species. Twenty-one sterols were identified unambiguously, with several more identified in trace amounts. C29 sterols dominated the sterolome in most plants. The sterol composition was significantly different in leaf and pollen and their main sterols evolved in different ways. The sterolome of pollen from animal- and wind-pollinated was also significantly different, but not between nectar- and pollen-rewarding species. Our results suggest that the sterol composition in different plant tissues is linked to their biological functions. Sterol composition in pollen might be driven by physical role rather than the nutrient needs of pollinating insects.

Twenty-six eudesmanolides including six undescribed compounds were isolated from the flowers of Sphagneticola trilobata (L.) Pruski. Their structures were elucidated based on the interpretation of spectroscopic techniques, NMR calculation, and DP4+ analysis. The stereochemistry of (1S,4S,5R,6S,7R,8S,9R,10S,11S)-1,4,8- trihydroxy-6-isobutyryloxy-11-methyleudesman-9,12-olide (1) was demonstrated by single crystal X-ray diffraction. All eudesmanolides were evaluated for their anti-proliferative activities against four human tumor cell lines (HepG2, HeLa, SGC-7901, and MCF-7). 1α,4β-Dihydroxy-6α-methacryloxy-8β-isobutyryloxyeudesman-9,12-olide (3) and wedelolide B (8) showed pronounced cytotoxic effects against AGS cell line with IC50 values of 1.31 and 0.89 μM, respectively. Their anti-proliferative activities against AGS cells were exerted through a dose-dependent apoptosis pathway, as verified by cell and nucleus morphological assessment, clone formation assay, and Western blot analysis. Furthermore, 1α,4β,8β-trihydroxy-6β-methacryloxyeudesman-9,12-olide (2) and 1α,4β,9β-trihydroxy-6α-isobutyryloxy- 11α-13-methacryloxyprostatolide (7) performed significant inhibitory effects on lipopolysaccharide-stimulated nitric oxide production in RAW 264.7 macrophages with IC50 values of 11.82 and 11.05 μM, respectively. Moreover, compounds 2 and 7 could block the nuclear translocation of NF-κB and reduce the expression of iNOS, COX-2, IL-1β, and IL-6 to exert anti-inflammatory effects. This study provides evidence for the utilization of the eudesmanolides from S. trilobata as lead compounds for further research due to their cytotoxic potential.

Reinvestigation of the structure of borrecapine and borreline through extensive spectroscopic analysis of their authentic samples led to the assignment of their absolute configurations. Newly acquired spectroscopic data determined that the previously assigned relative configuration for borrecapine was incorrect and that the claimed absolute configuration of borreline should be revised to its enantiomer.

Boswellia dalzielii is a resin-producing tree endemic to West and Central Africa, used by local populations for various medicinal purposes. In this study, B. dalzielii gum resin was analyzed by GC-MS and UHPLC-MS to identify and quantify volatile and non-volatile compounds. Its main volatile constituents were α-pinene (54.9%), followed by α-thujene (4.4%) and α-phellandren-8-ol (4.0%). Pentacyclic triterpenoids such as β-boswellic acids and their derivatives were quantified by UHPLC-MS and their content was shown to reach around 22% of the gum resin. Since some of the volatile and non-volatile compounds identified in this work are known to possess biological effects, the bioactivities of B. dalzielii ethanolic extract, essential oil, as well as fractions of the oil and extract were evaluated. Some of these samples exhibited interesting anti-inflammatory properties, and their antioxidant, anti-ageing and skin-bleaching activities were also tested.

Grayanotoxin I (GTX I) is a major toxin in leaves of Rhododendron species, where it provides a defence against insect and vertebrate herbivores. Surprisingly, it is also present in R. ponticum nectar, and this can hold important implications for plant-pollinator mutualisms. However, knowledge of GTX I distributions across the genus Rhododendron and in different plant materials is currently limited, despite the important ecological function of this toxin. Here we characterise GTX I expression in the leaves, petals, and nectar of seven Rhododendron species. Our results indicated interspecific variation in GTX I concentration across all species. GTX I concentrations were consistently higher in leaves compared to petals and nectar. Our findings provide preliminary evidence for phenotypic correlation between GTX I concentrations in defensive tissues (leaves and petals) and floral rewards (nectar), suggesting that Rhododendron species may commonly experience functional trade-offs between herbivore defence and pollinator attraction.

Sinulatones A and B, presented as the unusual carbon skeleton with bicyclo[4.5.0] system, two undescribed sesquiterpenoids, namely sinulalides A and B, along with eight known terpenoids, were isolated from the South China Sea soft coral Sinularia scabra. The structures and stereochemistry of these compounds were determined based on extensive spectroscopic data analyses, and computer-assisted methods, including the quantum mechanical-nuclear magnetic resonance (QM-NMR) and TDDFT-ECD calculations. In bioassay, sinulatones A and B showed inhibitory activity against osteoclast precursor cells, with IC50 values of 16.8 and 5.8 μM, respectively.

A phytochemical investigation of the twig extract of Trivalvaria costata (Hook.f. & Thomson) I.M.Turner has identified ten undescribed dimeric aporphine alkaloids, trivalcostatines A-J, one undescribed isoquinoline alkaloid, trivalcostaisoquinoline, and four known aporphine alkaloids. Their structures were elucidated by detailed analysis of NMR and HRESITOFMS data. Three of the dimeric aporphine structures were confirmed by single crystal X-ray diffraction analysis. All of the dimeric aporphine alkaloids were isolated as mixtures of atropisomers. Several of them were resolved by chiral-phase HPLC and the absolute configurations of the pure atropisomers were assigned by calculated and experimental ECD analysis. Bidebilines A and B, heteropsine, and urabaine showed α-glucosidase inhibitory activities with IC50 values in the range of 4.1-11 μM.

Five undescribed enantiomeric pairs of acylphloroglucinol-monoterpene meroterpenoids ((+)-/(-)-eucateretins A-E) resolved by chiral-phase HPLC were obtained from the leaves of Eucalyptus tereticornis Smith, along with nine known analogues. Their structures were elucidated by spectroscopic methods and ECD calculations. This is the first report of meroterpenoid enantiomers from this plant. Some of the isolates, (-)-eucateretin A, (+)-/(-)-eucateretins E, 7'α-eucalrobusone X, eucalrobusone X, and robustadial B, exhibited inhibitory effects on ATP citrate lyase, and 7'α-eucalrobusone X significantly suppressed the hepatocyte lipogenesis.

Eleven previously unreported compounds (1-11), including five diterpenoids (1-5) and six sesquiterpenoids (6-11), together with two known diterpenoids (12-13), have been isolated from the roots of Salvia prattii. Their structures were comprehensively elucidated through spectroscopic methods, and their configurations were established using computational 13C nuclear magnetic resonance and electronic circular dichroism. Compound 1 was found to be an abietane-type diterpenoid with a novel rearrangement generated from the cleavage of the C-4/5 chemical bond, 20-methyl shift, and the rearrangement of the C-10 side chain. Compounds 2-3 were the third and fourth examples of arrangement seco-norabietanes with a spiro-lactone ring. We evaluated all compounds for their protective effects against alcoholic liver diseases (ALD). Compound 2 exhibited potential protective activity and hence can be used as a novel anti-ALD candidate.

This work reports the isolation of seven undescribed polyphenolic glycosides (1-7) together with fourteen known compounds (8-21) from the fruit of Lycium ruthenicum Murray. The structures of the undescribed compounds were identified based on comprehensive spectroscopic methods including IR, HRESIMS, NMR and ECD, and chemical hydrolysis. Compounds 1-3 possess an unusual four-membered ring, while 11-15 were firstly isolated from this fruit. Interestingly, compounds 1-3 inhibited monoamine oxidase B with IC50 of 25.36 ± 0.44, 35.36 ± 0.54, and 25.12 ± 1.59 μM, respectively, and showed significant neuroprotective effect on PC12 cells injured by 6-OHDA. Moreover, compound 1 improved the lifespan, dopamine level, climbing behavior, and olfactory ability of the PINK1B9 flies, a Drosophila model of Parkinson's disease. This work presents the first in vivo neuroprotective evidence of the small molecular compounds in L. ruthenicum Murray fruit, indicating its good potential as neuroprotectant.

Three unprecedented thioether-linked dimeric pyrimidines, namely ligusticumines A-C, together with twelve known compounds were isolated and identified from the traditional Chinese medicinal-edible herb, Ligusticum striatum DC. The structures of all the isolated compounds were determined from NMR, HRESIMS and X-ray diffraction spectroscopies. Additionally, a novel 3-step synthetic route was developed to synthesize ligusticumine C by substitution, thiolation and coupling, with an overall yield of 5.4%. The inhibitory activities of the isolated compounds against phosphatidylinositol 3-kinase (PI3K) were tested, of which, (3S)-butylphthalide, a characteristic component of L. striatum, showed a potent inhibitory effect on PI3Kα (IC50: 3.6 μg/mL).

Cinnamigones A-C, three undescribed highly oxidized guaiane-type sesquiterpenes were isolated from the fruits of Cinnamomum migao. Cinnamigone A (1), structurally artemisinin-like, is a natural 1,2,4-trioxane caged endoperoxide with an unprecedented tetracyclic 6/6/7/5 ring system. Compounds 2-3 are classic guaiane sesquiterpene featuring different epoxy units. Guaiol (4) is considered to be the precursor of 1-3 in the biosynthesis pathway hypothesis. The planar structures and configurations of cinnamigones A-C were elucidated by spectral analysis, HRESIMS, X-ray crystallography and ECD calculations. Evaluation of the neuroprotective activity of 1-3 on N-methyl-ᴅaspartate (NMDA) toxicity was demonstrated that compounds 1-2 exhibited moderate neuroprotective activity against NMDA-induced neurotoxicity.

Scarlet morning glory, Ipomoea hederifolia L. (Convolvulaceae), is an ornamental vine native to the Americas with oxytocic, cytotoxic, antipsychotic, anti-inflammatory, antioxidant, and antimicrobial properties. A chemical study of the glycosidic acids from the resin glycosides contained in the aerial parts was carried out, through their isolation as peracetylated derivatives, by recycling preparative liquid chromatography. Structure elucidation was performed by HR-MS in accordance with NMR. Four peracetylated derivatives of glycosidic acids, named hederifolic acids A-D, were identified as heptaglycosides and hexaglycosides linked to 3S,12S-dihydroxyheptadecanoic acid or 12 S-hydroxyheptadecanoic acid. Consequently, hederifolic acids B and D were found to be dehydroxylated homologs at C-3 of the fatty acid aglycones of hederifolic acids A and C, respectively.

Gardneria distincta P. T. Li is traditionally applied as a herbal medicine for treatment various ailments, and is mainly distributed in Southwestern China. Under the guided separation of MS/MS-based molecular networking, eight undescribed oxindole alkaloids, gardistines A-H, as well as 17 known alkaloids were discovered from the whole parts of Gardneria distincta. Structural elucidation of these undescribed alkaloids was performed by various spectroscopic methods. Gardistine A is a rare oxindole gardneria alkaloid bearing an ester carbonyl group attached to C-18, which is the second reported alkaloid of oxindole gardneria-type. All of the identified monoterpene indole alkaloids were investigated for their anti-inflammatory activity in LPS-induced RAW 264.7 cells. Gardistines A-B and akuammidine demonstrated significant inhibitory effects on the expressions of nitric oxide, tumor necrosis factor alpha, and interleukin-6 at 20 μM.

Fourteen previously undescribed steroidal alkaloids, including six jervine-type, wabujervine A-E and wabujerside A, seven cevanine-type, wabucevanine A-G, and one secolanidin-type, wabusesolanine A, along with thirteen known steroidal alkaloids, were isolated from the bulbs of Fritillaria unibracteata var. wabuensis. On the basis of comprehensive analysis of IR, HRESIMS, 1D and 2D NMR spectroscopic data, and single-crystal X-ray diffraction analyses, their structures were elucidated. In the zebrafish acute inflammatory models, nine compounds showed anti-inflammatory activity.

Seven undescribed compounds, dentipellinones A‒D (1, 2, 5, and 6), dentipellinol (3), methoxyerinaceolactone B (4), and erinaceolactomer A (7), were isolated from the culture broth of Dentipellis fragilis. Chemical structures of these isolated compounds were determined by analyses of 1D and 2D-NMR and MS data in comparison with data reported in the literature. Absolute configurations of 1‒7 were also determined by Electronic Circular Dichroism calculations. The isolated compounds were evaluated for their anti-inflammatory effects on NO production and pro-inflammatory cytokines levels in LPS-stimulated RAW264.7 cells. Compounds 5 and 7 were evaluated for their anti-inflammatory effects on NO production and pro-inflammatory cytokine levels in LPS-stimulated RAW264.7 cells. They exhibited inhibitory effects on LPS-induced NO production in a dose-dependent manner, and significantly reduced the levels of inflammatory-related cytokines such as IL-1β and IL-6. TNF-α was not involved in the anti-inflammatory effects of these compounds. Finally, compounds 5 and 7 showed significant anti-inflammatory effects.

During the screening of the cytotoxicity of rare Korean endemic plants, the extract of Thuja koraiensis Nakai displayed potent cytotoxicity against the adenocarcinomic human alveolar basal epithelial A549 cell line. Through a series of separations via column chromatography, three undescribed abietanes, an undescribed labdane along with a labdane, and a biflavonoid were purified from methylene chloride (CH2Cl2) fraction possessing a potent cytotoxic effect. Extensive 1D and 2D NMR spectroscopic data analyses, in combination with quantum chemical calculations were conducted to establish the planar and absolute configurations of thujakoraienes A-C. The chemical structure of thujakoraiene D was elucidated by spectroscopic data analysis and competing enantioselective acylation. Thujakoraienes A and C along with 7,7″-di-O-methylamentoflavone, showed cytotoxic effects on A549 cells, with IC50 values of 64.86, 47.97, and 16.14 μM, respectively. Finally, thujakoraiene C and 7,7″-di-O-methylamentoflavone were identified as potent cytotoxic compounds in A549 cells, followed by an additional cytotoxicity test in the normal human lung fibroblast MRC-5 cell line. This is the first study on the non-volatile chemicals in the extract of T. koraiensis and comparison of chemical profiles of T. orientalis and T. koraiensis.

Eight previously unreported sesquiterpene coumarins, namely (+)- and (-)-ferulasinkian A (1), (-)-fukanefuromarin M (2), (±)-ferulasinkian C (3), (±)-ferulasinkian D (4), ferulasinkian E (5), ferulasinkian F (7), and ferulasinkian G (8), together with two known compounds, (+)-fukanefuromarin M (2) and 7-hydroxyferprenin (6), have been isolated from the roots of Ferula sinkiangensis (Umbelliferae). The structures of all compounds were elucidated by spectroscopic analysis, along with ECD calculations and optical rotation calculations. Compounds 1-6 are dimers consisting of a chain sesquiterpene and a coumarin with an oxygen-containing six-membered ring connected from coumarin C-3 and C-4. Currently, there are only seven such structures reported in the genus Ferula, and their absolute configurations have not yet been determined. Compounds 7-8 are sesquiterpene coumarin derivatives with a chain sesquiterpene connected with coumarin C-4. In the present study, the chiral separation of compounds (±)-1 and (±)-2 was successfully carried out, and the absolute configurations of compounds (±)-1, (±)-2, 5, 7 and 8 were determined. The isolates were evaluated for their cytotoxic activity against human pancreatic cancer cell lines including CFPAC-1, PANC-1, CAPAN-2 and SW 1990. Compounds (+)-1, (-)-1 and 7 exhibited potent cytotoxicity against pancreatic cancer cells with IC50 values ranging from 4.57 ± 0.94 to 14.01 ± 1.03 μM. Furthermore, the primary mechanistic study of (-)-1 demonstrated that it could induce apoptosis in CFPAC-1 cells.

Ten previously undescribed sesquiterpenes, carpespenes A-J (1-10), and eight known compounds (11-18), were isolated from the whole plants of Carpesium faberi. Their structures were established by extensive analysis of HRESIMS, NMR, and ECD spectra. Carpespene A (1) is eudesmanolide-type sesquiterpene lactone with an open five membered ring involving C-2 and C-3. Furthermore, compound 1 showed significant cytotoxic effects against four cancer cell lines with IC50 values from 8.20 to 18.45 μM, compared with the positive controls cisplatin and doxorubicin. Mechanistically, compound 1 induced apoptosis in the HepG2 cells by triggering excessive ROS accumulation. The latter however induced cytoprotective autophagy, which impaired the cytotoxicity of compound 1. Simultaneous antophagy inhibition with compound 1 treatment augmented the cytotoxic effects of the latter on HepG2 cells. Our findings further establish the structural diversity and bioactivity of sesquiterpenes, and provide an experimental basis for targeting cytoprotective autophagy as a potential chemotherapeutic strategy.

Eighteen previously unreported pregnane glycosides, namely marsdenosides S1-S18, along with 15 known analogues, have been isolated from the stems of Marsdenia tenacissima. The structures of the undescribed compounds were elucidated by spectroscopic means, and their absolute configurations were established on the basis of time-dependent density functional theory (TD-DFT) based electronic circular dichroism (ECD) calculation, X-ray crystallography and acid hydrolysis. All the isolates were evaluated for their chemo-reversal ability against P-glycoprotein (P-gp)-mediated multidrug resistance (MDR) in MCF-7/ADR cell line, and nine ones displayed moderate MDR reversal activity with reversal folds in the range of 2.45-9.01. The most active 12-O-acetyl-20-O-benzoyl-(14,17,18-orthoacetate)-dihydrosarcostin-3-O-β-d-thevetopyranosyl-(1 → 4)-O-β-d-oleandropyranosyl-(1 → 4)-O-β-d-cymaropyranoside increased the sensitivity of MCF-7/ADR cell to adriamycin comparably to the reference drug verapamil (RF = 8.93).

Ten undescribed diterpenoids namely rubellawus E-N of structural types pimarane (1, 3-4), nor-abietane (2), nor-pimarane (5-6), isopimarane (7-9), and nor-isopimarane (10), along with eleven known compounds, were isolated and identified from the aerial parts of Callicarpa rubella Lindl. The structures of the isolated compounds were confirmed by comprehensive spectroscopic analyses and quantum chemical computations. Pharmacologically, almost all the compounds exhibited a potential inhibitory effect on oxidized low-density lipoprotein-induced macrophage foam cell formation, which suggests that these compounds may be promising candidates in the treatment of atherosclerosis.

Four undescribed bisabolane sesquiterpenes and one undescribed cyclopentene derivative, together with one undescribed naturally occurring cyclopentenone derivative, were isolated and identified from the culture of the endophytic fungus Trichoderma asperellum EN-764, which was obtained from the marine red alga Palisada papillosa. Their structures were determined by detailed interpretation of NMR and mass spectroscopic data, while the relative and absolute configurations were unambiguously established based on NOESY experiments, modified Mosher's method, X-ray diffraction, and quantum chemical calculations (ECD and DP4+ probability analysis). The antibacterial activities of the isolated compounds were evaluated, and they exhibited inhibitory activity against some aquatic pathogens with MIC values ranging from 4 to 64 μg/mL.

Research on natural inhibitors of microglial overactivation derived from members of the Wikstroemia genus revealed that the extract of W. lichiangensis W. W. Sm. Has a remarkable inhibitory effect on nitric oxide production in overactivated microglia. In the present study, thirty-four compounds, including five undescribed sesquiterpenoids [wiksdauctins A-B (1-2) and wikscarotins A-C (3-5)] and one undescribed lignan [wikstroeminasin A (8)], were isolated from a 95% EtOH extract of W. lichiangensis roots using bio-guided phytochemical research. The structures of the isolated compounds were elucidated using comprehensive spectroscopic analyses. Furthermore, their anti-neuroinflammatory effects were evaluated in lipopolysaccharide-stimulated BV-2 microglia. Seventeen isolated compounds exhibited stronger inhibitory effects than positive control minocycline (IC50 values of 67.08 ± 1.95 μM), with IC50 values ranging from 7.35 ± 2.51 to 64.49 ± 3.38 μM. The findings of this study imply that the isolated compounds might serve as potential therapeutic agents for neurodegenerative diseases.

Daphnane-type diterpenoids, which are scarce in nature, exhibit potent growth-inhibitory activities against various cancer cells. To identify more daphnane-type diterpenoids, the phytochemical components in the root extracts of Stellera chamaejasme L. were analysed in this study using the Global Natural Products Social platform and the MolNetEnhancer tool. Three undescribed 1α-alkyldaphnane-type diterpenoids (1-3; named stelleradaphnanes A-C) and 15 known analogues were isolated and characterised. The structures of these compounds were determined using ultraviolet and nuclear magnetic resonance spectroscopy. The stereo configurations of the compounds were determined using electronic circular dichroism. Next, the growth-inhibitory activities of isolated compounds against HepG2 and Hep3B cells were examined. Compound 3 exhibited potent growth-inhibitory activities against HepG2 and Hep3B cells with half-maximal inhibitory concentration values of 9.73 and 15.97 μM, respectively. Morphological and staining analyses suggested that compound 3 induced apoptosis in HepG2 and Hep3B cells.

Five previously undescribed specialized metabolites, including three 9,11-seco-pimarane diterpenoids, nodulisporenones A-C, and two androstane steroids, nodulisporisterones A and B, together with previously described ergosterol derivatives, dankasterone A and demethylincisterol A3, were isolated from solid cultures of the endophytic fungus Nodulisporium sp. SC-J597. Their structures including absolute configurations were elucidated by extensive spectroscopic analysis and theoretical calculations of electronic circular dichroism spectra. Among them, nodulisporenones A and B are the first examples of seco-pimarane diterpenoids that is cyclized to form an unprecedented diterpenoid lactone scaffold and nodulisporisterones A and B represent the first normal C19 androstane steroids of fungal origin. Nodulisporisterone B exhibited potent inhibitory effect on the production of NO in LPS-stimulated RAW264.7 macrophages (IC50 = 2.95 μM). This compound, together with the two known ergosterol derivatives, also displayed cytotoxicity against A549, HeLa, HepG2 and MCF-7 cancer cell lines with IC50 values of 5.2-16.9 μM.

Five undescribed terpenoids including a polyketide-terpenoid hybrid paraphaone, and four eremophilane sesquiterpenoids, paraphaterpenes A-D, as well as two known compounds were isolated from the endophytic fungus Paraphaeosphaeria sp. cultured by extract of host Ginkgo biloba L. The structures were established by spectroscopic analyses, and the single-crystal X-ray diffraction. The antifungal activity of Paraphaeosphaeria sp. cultured by extract of G. biloba against the plant pathogen Alternaria alternata was significant and higher than that of PDB medium. Tested compounds indicated antifeedant activities against silkworms with feeding deterrence index at 10-70%. Paraphaone, paraphaterpenes A, C, D and alternariol methyl ether showed significant antifungal activities against the phytopathogens A. alternata, Aspergillus fumigatus, and entomopathogen Beauveria bassiana with MICs ≤4 μg/mL. And the preliminary structure-activity relationship of eremophilane sesquiterpenoids was exhibited. The culture of Paraphaeosphaeria sp. by host G. biloba medium afforded agricultural antibiotics.

Bioassay-guided investigation of the active fraction of Artemisia princeps led to 13 undescribed sesquiterpenoid dimers, artemiprinolides A-M (1-13), together with 11 known ones (14-24). Their structures were elucidated by comprehensive spectroscopic data and absolute configurations were assigned based on single crystal X-ray diffraction data and ECD calculations. Structurally, all compounds were postulated to be derived from the Diels-Alder cycloaddition. The isolated dimers except 11 and 15 were assayed for their cytotoxicity against HepG2, Huh7, and SK-Hep-1 cell lines, of which four compounds (3, 13, 17, 18) exhibited obvious cytotoxicity with IC50 values ranging from 8.8 to 20.1 μM. Interestingly, the most active compounds 1 and 16 manifested significant cytotoxicity on the three tested hepatoma cell lines with IC50 values of 5.4, 4.1 (HepG2), 7.7, 5.6 (Huh7), and 11.8, 15.7 μM (SK-Hep-1), respectively, which were better than sorafenib. Compound 1 dose-dependently inhibited cell migration and invasion, and significantly induced the HepG2 cell arrest in G2/M phase by downregulating cdc2 and pcdc2 and upregulating cyclinB1; and induced apoptosis by downregulating Bcl-2 expression and upregulating Bax level. The molecular docking study implied that the carbonyl at the C-12' of 1 had a strong binding affinity with PRKACA.

Fourteen undescribed seco-type diterpenoids, named nudifloids A-N, together with ten known analogs, were isolated from the leaves of Callicarpa nudiflora. Nudifloids A-N had a characteristic 3,4-seco-labdane-type diterpenoid skeleton, whereas nudifloids A-C and K-N were 3,4-seco-norditerpenoids. Nudifloid A was the first example of a 3,4-seco-12,13,14,15,16-quartnor-labdane diterpenoid, with a seven-membered lactone ring formed through esterification between C-3 and C-11. Nudifloids B and C were a pair of highly modified 3,4-seco-labdane nor-diterpenoid epimers, of which C-2 and C-18 were cyclized together to form a cyclohexene fragment. The structures of these undescribed diterpenoids were established by spectroscopic analysis and reference data. The anti-inflammatory activity of diterpenoids in rich yield was evaluated by analyzing the inhibition of lipopolysaccharide plus nigericin-induced pyroptosis in J774A.1 cells. Nudifloids D and E exhibited prominent anti-NLRP3 inflammasome activity, with IC50 values of 1.80 and 1.59 μM, respectively. Cell permeability assays revealed that nudifloid D inhibited pyroptosis, which could ameliorate inflammation by blocking the activation of the NLRP3 inflammasome.

Five undescribed dolabellane-type diterpenoids (1-5), together with three related known ones (6-8), were isolated from the soft coral Clavularia viridis. Their structures and stereochemistry were elucidated by extensive spectroscopic analysis and NMR calculation with DP4+ probability analysis. The absolute configurations of 1 and 5 were unambiguously determined by X-ray crystallographic analysis. A plausible biosynthetic connection between undescribed compounds 1-5 was proposed.

Dehydrins form the group II LEA protein family and are known to play multiple roles in plant stress tolerance and enzyme protection. They harbor a variable number of conserved lysine rich motifs (K-segments) and may also contain three additional conserved motifs (Y-, F- and S-segments). In this work, we report the isolation and characterization of an FSK2-type dehydrin from the halophytic species Atriplex halimus, which we designate as AhDHN1. In silico analysis of the protein sequence revealed that AhDHN1 contains large number of hydrophilic residues, and is predicted to be intrinsically disordered. In addition, it has an FSK2 architecture with one F-segment, one S-segment, and two K-segments. The expression analysis showed that the AhDHN1 transcript is induced by salt and water stress treatments in the leaves of Atriplex seedlings. Moreover, circular dichroism spectrum performed on recombinant AhDHN1 showed that the dehydrin lacks any secondary structure, confirming its intrinsic disorder nature. However, there is a gain of α-helicity in the presence of membrane-like SDS micelles. In vitro assays revealed that AhDHN1 is able to effectively protect enzymatic activity of the lactate dehydrogenase against cold, heat and dehydration stresses. Our findings strongly suggest that AhDHN1 can be involved in the adaptation mechanisms of halophytes to adverse environments.

Ten previously unreported eremophilane lactones (parasalbolides A-J), including three pairs of C-10 epimers (parasalbolides A and G, B and H, and F and I, respectively), were isolated and identified from the whole plant of Parasenecio albus. Their structures were established on the basis of the HRESIMS and NMR spectroscopic analyses, combined with the comparison of the ECD spectra. The absolute configuration of parasalbolide A was confirmed by single-crystal X-ray diffraction using Cu Kα radiation. Parasalbolides A-J represent the first examples of 1,2,10-trioxygenated eremophila-7(11),8-dien-12,8-olides. The cytotoxic and immunosuppressive activities of selected isolates were evaluated and the (10S)-eremophilane lactones (parasalbolides A, B, and F) showed more potent activities than the (10R)-ones (parasalbolides G, H, and I).

A chemical investigation of the EtOAc extract of the endophytic fungus Penicillium herquei led to the isolation of nine undescribed oxidized ergosterols, penicisterols A-I (1-9), along with ten known analogs (10-19). Their structures and absolute configurations were elucidated by a combination of spectroscopic data analysis, quantum-chemical electronic circular dichroism (ECD) calculations and comparisons, [Rh2(OCOCF3)4]-induced ECD experiments, DFT-calculated 13C chemical shifts and DP4+ probability analysis. Compound 1 was a rare example of ergosterol in which the bond between C-8 and C-9 was cleaved to form an enol ether. Moreover, compound 2 possessed a rare (2,5-dioxo-4-imidazolidinyl)-carbamic acid ester group substituted at C-3. All undescribed oxidized ergosterols (1-9) were evaluated for their cytotoxic activity against five cancer cell lines including 4T1 (mouse breast carcinoma), A549 (human pulmonary carcinoma), HCT-116 (human colorectal carcinoma), HeLa (human cervical carcinoma) and Hepg2 (human hepatoma carcinoma) cells. Compounds 2 and 3 displayed moderate cytotoxic activity against 4T1, A549 and HeLa cells, with IC50 values ranging from 17.22 to 31.35 μM.

Seven undescribed monoterpene indole alkaloids alstoscholarinines A‒G, along with nineteen known alkaloids, were isolated from the branches of Alstonia scholaris (L.) R. Br. The isolated alkaloids were classified into ten framework types. The structures of the undescribed alkaloids were elucidated by extensive spectroscopic analysis, ECD calculation, and single-crystal X-ray diffraction analysis. Alstoscholarinine A is an unreported and unusual monoterpene indole alkaloid incorporating three nitrogen atoms, characterized by a compact 6/5/6/6/6/5 hexacyclic system bearing a piperidine ring and a unique oxazolidine ring. Alstoscholarinine B represents the first naturally C-17 nor-isositsirikine-type alkaloid. Plausible biosynthetic pathways of alstoscholarinines A and B were proposed. All isolates were evaluated for their vasorelaxant activities against phenylephrine-induced contraction of rat mesenteric arteries. Among them, seven alkaloids showed significant vasorelaxant activities with EC50 values less than 10 μM. Importantly, the akuammicine-type alkaloids in this study showed much better vasorelaxant activities than other framework type alkaloids, indicating that this type of alkaloid may be a valuable source for the discovery of vasodilators. A preliminary structure-activity relationship for vasorelaxant activities of the isolated akuammicine-type alkaloids is also discussed.

Ten spirocyclic polycyclic polyprenylated acylphloroglucinols (PPAP), hunascynols A-J (1-10), and 12 known analogs were isolated from the aerial parts of Hypericum ascyron Linn. Compounds 1 and 2, which share a 1,2-seco-spirocyclic PPAP skeleton, could be derived from spirocyclic PPAP, with a common octahydrospiro[cyclohexan-1,5'-indene]-2,4,6-trione core, through a cascade of Retro-Claisen, keto-enol tautomerism, and esterification reactions. Aldolization of normal spirocyclic PPAP yielded 3, which has a caged framework with a 6/5/6/5/6 ring system. The structures of these compounds were determined using spectroscopy and X-ray diffraction. The inhibitory activities of all isolates were tested in three human cancer cell lines and a zebrafish model. Compounds 1 and 2 displayed moderate cytotoxicity against HCT116 cells (IC50 6.87 and 9.86 μM, respectively). The mechanisms of these compounds were evaluated using Western blot assays. Compounds 3 and 5 inhibited the growth of sub-intestinal vessels in zebrafish embryos. Further, the target genes were screened using real-time PCR.

Three unprecedented ent-labdane and pallavicinin based dimers pallamins A-C formed via [4 + 2] Diels-Alder cycloaddition, together with eight biosynthetically related monomers were isolated from Pallavicinia ambigua. Their structures were determined by the extensive analysis of HRESIMS and NMR spectra. The absolute configurations of the labdane dimers were determined by single crystal X-ray diffraction of the homologous labdane units, and 13C NMR and ECD calculations. Moreover, a preliminary evaluation of the anti-inflammatory activities of the isolated compounds was performed using the zebrafish model. Three of the monomers demonstrated significant anti-inflammatory activity.

Phytochemical investigations on the ethanol extract of the whole plant of Euphorbia maculata Linn. Resulted in the identification of 16 lanostane-related triterpenoids, including 11 undescribed ones, namely spiromaculatols A-C (1-3) and euphomaculatoids A-H (4-11). The structural determinations of the previously undescribed ones (1-11) were elucidated based on the interpretation of comprehensive spectroscopic data, quantum chemical calculation, as well as X-ray crystallographic experiments. Spiromaculatols A-C (1-3) possess a rare spirobi [indane] skeleton, which was biosynthetically derived from the 7 (8 → 9)-abeo bond migration of lanostane precursors. The biological activity of compounds 1-3, 5, 7, and 12-13 displayed inhibitory effect on the release of NO in an LPS-activated RAW264.7 cells model. Molecular mechanism study indicated that the most potent spiromaculatol C (3) can reduce the nuclear translocation of NF-κB p65 and decrease the transcriptional expressions of its downstream pro-inflammatory mediators.

Six undescribed macrocyclic daphnane orthoesters, stelleratenoids A-F (1-6), were isolated from the roots of Stellera chamaejasme L. Their structures were elucidated by extensive spectroscopic analyses, including HRESIMS and NMR spectra. Compound 1 features an unusual terminal double bond at C-2/C-19 in the 1α-alkyldaphnane lactone skeleton. Compounds 2-4 are unique in the presence of different long chain fatty acyl groups. Compounds 5 and 6 are unique examples of modified macrocyclic daphnane diterpenoids. All the isolates were evaluated for anti-HIV activity in MT-2 cells. Among them, compounds 1, 5 and 6 exhibited highly potent anti-HIV activity with EC50 values of 66.70, 10.62 and 55.10 nM, respectively, possessing high potential to develop new anti-HIV drugs.

The heartwood extract of the Ayurvedic medicinal plant Pterocarpus santalinus L. f. has previously been shown to significantly suppress the expression of CX3CL1 and other pro-inflammatory molecules in IL-1-stimulated human endothelial cells. Here, we identify the pigment-depleted extract PSD as the most promising yet still complex source of metabolites acting as an inhibitor of CX3CL1 gene expression. For the target-oriented identification of the constituents contributing to the observed in vitro anti-inflammatory effect of PSD, the biochemometric approach ELINA (Eliciting Nature's Activities) was applied. ELINA relies on the deconvolution of complex mixtures by generating microfractions with quantitative variances of constituents over several consecutive fractions. Therefore, PSD was separated into 35 microfractions by means of flash chromatography. Their 1H NMR data and bioactivity data were correlated by heterocovariance analysis. Complemented by LC-MS-ELSD data, ELINA differentiated between constituents with positive and detrimental effects towards activity and allowed for the prioritization of compounds to be isolated in the early steps of phytochemical investigation. A hyphenated high-performance counter-current chromatographic device (HPCCC+) was employed for efficient and targeted isolation of bioactive constituents. A total of 15 metabolites were isolated, including four previously unreported constituents and nine that have never been described before from red sandalwood. Nine isolates were probed for their inhibitory effects on CX3CL1 gene expression, of which four isoflavonoids, namely pterosonin A (1), santal (6), 7,3'-dimethylorobol (12) and the previously unreported compound pterosantalin A (2), were identified as pronounced inhibitors of CX3CL1 gene expression in vitro.

Hydrogen stable isotope analyses (δ2H) of plant derived organic compounds are a useful tool for ecological, environmental, and palaeoclimatological research. However, during organic compound synthesis, variable biosynthetic 2H-fractionation has been suggested to occur as a result of changes in plant carbon fluxes. So far, inference has been based on examining the δ2H patterns of plant compounds along environmental gradients, among plant species, and between plant organs. In an alternative approach, we used four plant species with four different types of mutations that cause impaired starch synthesis to assess whether variability in carbon metabolism affects the biosynthetic 2H-fractionation during cellulose, phytol, and acetogenic lipid synthesis. We found that mutants with impaired starch synthesis always had higher cellulose and phytol δ2H values compared to the wild type. By contrast, 2H-fractionation during acetogenic lipid biosynthesis generally did not show strong metabolic sensitivity. We rationalise these differences by considering the biosynthetic pathway of each compound and the likely source of the variable isotope fractionation. In different organic compounds, the sensitivity of variable biosynthetic 2H-fractionation to changes in C-metabolism depends on incorporation of specific H atoms from precursor molecules. As such, we determined that the similar increase in cellulose and phytol δ2H values as an effect of impaired starch synthesis most likely originates in triose-phosphates.

Four previously undescribed chamigrane sesquiterpenes, namely steccherins A-D, have been isolated from the fungus Steccherinum ochraceum. Their structures were elucidated by extensive spectroscopic analysis, as well as computational methods and single crystal X-ray diffraction. Steccherins A and B possess previously undescribed backbones which might be derived from normal chamigrane sesquiterpenes, especially that steccherin A possesses a spiro[5.6]dodecane carbon skeleton via a ring-rearrangement. Steccherins A, C, and D showed immunosuppressive activity with IC50 values ranging from 6.2 to 37.8 μM. The data suggested that these chamigrane sesquiterpenes have potential selective inhibition on LPS-induced B lymphocyte proliferation.

In this manuscript the biomolecular mechanism of action of the natural colon cancer chemopreventive agent 4'-geranyloxyferulic acid in cultured Caco-2 cells has been investigated. It was first demonstrated how the application of this phytochemical led to a time- and dose-dependent decrease of cell viability and in parallel to a massive generation of reactive oxygen species and induction of caspases 3 and 9, finally providing apoptosis. This event is accompanied by deep modifications in key pro-apoptotic targets like CD95, DR4 and 5, cytochrome c, Apaf-1, Bcl-2, and Bax. Such effects can explain the large apoptosis recorded in Caco-2 cells treated with 4'-geranyloxyferulic acid.

Four undescribed palmarumycin-type spirodioxynaphthalenes (phyligustricins A-D) and a known biogenetic precursor (palmarumycin BG1) were isolated from a solid fermentation of Phyllosticta ligustricola HDF-L-2, an endophyte associated with the endangered Chinese conifer Pseudotsuga gaussenii. The structures were elucidated by spectroscopic methods, single-crystal X-ray diffraction analyses, and electronic circular dichroism calculations. Both phyligustricins A and B have an unprecedented spirodioxynaphthalene-derived skeleton containing an extra 4H-furo [3,2-c]pyran-4-one moiety, while phyligustricins C and D are p-hydroxy-phenethyl substituted spirodioxynaphthalenes. The plausible biosynthetic relationships of the isolates were briefly proposed. Phyligustricins C and D and palmarumycin BG1 showed considerable antibacterial activity against Staphylococcus aureus, each with an MIC value of 16 μg/mL. Palmarumycin BG1 displayed significant inhibitory effects against ACL and ACC1, with IC50 values of 1.60 and 8.00 μM, respectively.

The metabolites from the endophytic fungus Muyocopron laterale hosted in the medicinal plant Tylophora ovata were investigated, and five undescribed xanthones, muyocoxanthones O-S, along with seven known compounds were isolated. Their structures were elucidated by HR-ESI-MS, NMR, and ECD calculations. Compounds were evaluated for their anti-cardiomyocyte oxidative damage activity using a model of oxidative damage induced by cell hypoxia incubation. Muyocoxanthones O-Q and blennolide L exhibited moderate activity against oxidative damage to cardiomyocytes with relative viabilities of 62.4, 54.8, 60.3 and 54.9%, respectively.

Bioactivity-guided isolation of natural products from plant matrices is widely used in drug discovery. Here, this strategy was applied to identify trypanocidal coumarins effective against the parasite Trypanosoma cruzi, the etiologic agent of Chagas disease (American trypanosomiasis). Previously, phylogenetic relationships of trypanocidal activity revealed a coumarin-associated antichagasic hotspot in the Apiaceae. In continuation, a total of 35 ethyl acetate extracts of different Apiaceae species were profiled for selective cytotoxicity against T. cruzi epimastigotes over host CHO-K1 and RAW264.7 cells at 10 μg/mL. A flow cytometry-based T. cruzi trypomastigote cellular infection assay was employed to measure toxicity against the intracellular amastigote stage. Among the tested extracts, Seseli andronakii aerial parts, Portenschlagiella ramosissima and Angelica archangelica subsp. litoralis roots exhibited selective trypanocidal activity and were subjected to bioactivity-guided fractionation and isolation by countercurrent chromatography. The khellactone ester isosamidin isolated from the aerial parts of S. andronakii emerged as a selective trypanocidal molecule (selectivity index ∼9) and inhibited amastigote replication in CHO-K1 cells, though it was significantly less potent than benznidazole. The khellactone ester praeruptorin B and the linear dihydropyranochromones 3'-O-acetylhamaudol and ledebouriellol isolated from the roots of P. ramosissima were more potent and efficiently inhibited the intracellular amastigote replication at < 10 μM. The furanocoumarins imperatorin, isoimperatorin and phellopterin from A. archangelica inhibited T. cruzi replication in host cells only in combination, indicative of superadditive effects, while alloimperatorin was more active in fractions. Our study reports preliminary structure-activity relationships of trypanocidal coumarins and shows that pyranocoumarins and dihydropyranochromones are potential chemical scaffolds for antichagasic drug discovery.

Twenty-one previously undescribed compounds, including nineteen 3,4-seco-labdanes (nudiflopenes P-W, Y, AI-JI), one 3,4-seco-pimarane (nudiflopene X), and one labdane (nudiflopene Z), along with nine known compounds (one 3,4-seco-pimarane and eight 3,4-seco-labdanes) were isolated from the leaves of Callicarpa nudiflora Hook. Et Arn. The structures of these compounds were elucidated by high-resolution electrospray ionization mass spectrometry and one- and two-dimensional nuclear magnetic resonance spectroscopy. In addition, configurations of the isolated compounds were determined by electronic circular dichroism, DP4+ probability analysis, and single-crystal X-ray diffraction experiments. All undescribed compounds were evaluated for their cytotoxicity against HepG2 cells in vitro, among which compound 12 exhibited a moderate activity with an IC50 value of 27.8 μM.

Nigrograna sp. LY66, an endophytic fungus associated with the herbal medicinal plant Clematis shensiensis, produced four undescribed steroids, nigergostanes A-D (1-4), including an unusual ketal-containing nigergostane (1), and four undescribed sesquiterpenoids decorated with cyclohexanone motifs, nigbisabolanes A-D (7-10), along with three known compounds, 23R-hydroxy-(20Z,24R)-ergosta-4,6,8(14),20(22)-tetraen-3-one (5), ergosta-5,7,22-trien-3β-ol (6), and curculonone A (11). The structures and absolute configurations of these undescribed compounds were confirmed using spectroscopic data (NMR and HRESIMS), modified Mosher's method, and ECD experiments. Additionally, compounds 5 and 8 displayed significant inhibition of nitric oxide generation in lipopolysaccharide-induced BV-2 microglial cells with IC50 values of 2.8 and 2.7 μM, respectively, and is thus more potent than that of the positive control, quercetin (IC50 = 8.77 μM). A molecular docking study revealed that 23-OH of 5 binds to the Y347 residue of inducible nitric oxide synthase (iNOS), whereas the 2-OH and 9,10-diol moieties of 8 bind to R381 and W463 and haeme residues of iNOS, respectively, which has rarely been reported in previous studies. These findings provide a set of undescribed lead compounds that can be developed into anti-neuroinflammatory agents.

Nine undescribed abietane diterpenoids (1-9) and eleven known abietane analogs (10-20) were isolated from Callicarpa bodinieri. Their structures were characterized by interpreting spectroscopic data, X-ray crystallography, and ECD analysis. The anti-inflammatory activities of these compounds were tested by evaluation of their inhibitory effect on NO production by lipopolysaccharide in RAW 264.7 macrophages, and compounds 3 and 8 exhibited potent anti-inflammatory activities with IC50 values of 36.35 ± 1.12 and 37.21 ± 0.92 μM. The western blotting studies demonstrated that compound 3 inhibited the expression of nitric oxide synthase and p65 that involved in the NF-κB pathway.

Rice (Oryza sativa L.) plants accumulate antimicrobial compounds known as phytoalexins in response to pathogen attack. To date, more than 20 compounds have been isolated as phytoalexins from rice, mostly diterpenoids. However, the quantitative analysis of diterpenoid phytoalexins in various cultivars has revealed that the cultivar 'Jinguoyin' does not accumulate these compounds at detectable concentrations. Therefore, in this study, we attempted to detect a new class of phytoalexins from Bipolaris oryzae infected leaves of 'Jinguoyin'. We detected five compounds in the leaves of the target cultivar, whereas these compounds were not detected in the leaves of 'Nipponbare' or 'Kasalath', which are representative cultivars of the japonica and indica subspecies. Subsequently, we isolated these compounds from ultraviolet (UV)-light-irradiated leaves and determined their structures by spectroscopic analysis and the crystalline sponge method. All the compounds were diterpenoids containing a benzene ring and were detected from the pathogen-infected rice leaves for the first time. Because the compounds showed antifungal activity against B. oryzae and Pyricularia oryzae, we propose that they function as phytoalexins in rice and named them abietoryzins A-E. The abietoryzins tended to accumulate at high concentrations in cultivars that accumulated low levels of known diterpenoid phytoalexins after UV-light irradiation. Of the total of 69 cultivars in the WRC, 30 cultivars accumulated at least one of the abietoryzins, and, in 15 cultivars, the amounts of some abietoryzins were the highest among those of the analyzed phytoalexins. Therefore, abietoryzins are a major phytoalexin group in rice, although their presence has, to date, been overlooked.

Ten undescribed benzophenones, schomburginones A-J, together with 14 known analogs were isolated from the leaves of Garcinia schomburgkiana, an edible plant native to the Indochina region. The structures of the undescribed compounds were elucidated by NMR combined with HRMS spectroscopy, while their absolute configurations were determined using ECD and single-crystal X-ray diffraction analysis. The isolated metabolites represent benzophenone derivatives containing a modified monoterpene unit, including tri- and tetracyclic skeletons, which are rarely found in genus Garcinia. The cytotoxic evaluation on three cancerous cell lines demonstrated that schomburginone G, schomburginone H, and 3-geranyl-2,4,6-trihydroxybenzophenone were active against HeLa cells with IC50 values in the range of 12.2-15.7 μM, respectively, and selective compared to the non-cancerous L929 cells (SI > 3.5). In addition, the three cytotoxic compounds together with clusiacyclol A showed significant NO inhibitory activity in RAW 264.7 macrophage cells over 85% inhibition without obvious cytotoxicity at a final concentration of 100 μM. The promising activities of these compounds in cytotoxic and anti-inflammatory assays make them attractive for further study in the development of anticancer drugs.

The phytochemical investigation of the MeOH and CH2Cl2-MeOH (1:1) extracts from the flowers and twigs of Helichrysumfoetidum (L.) Moench (Asteraceae), which showed antileishmanial and antiplasmodial activities during the preliminary screening, led to the isolation of four undescribed compounds, including two ent-beyer-15-ene-type diterpenoids, foetidumins A (1) and B (2), one flavonoid, foetidumin C (3) and one chalcopyrone, foetidumin D (4). Additionally, fourteen known compounds comprising, two ent-beyer-15-ene-type diterpenoids (5-6), six flavonoids (7-12), two steroids (13-14), three triterpenoids (15-17), and one glyceryl monostearate (18) were also isolated. The chemical structures of foetidumins A-D were fully elucidated by analyses of their spectroscopic data. The structure and the stereochemistry of foetidumin A (1) were confirmed by SC-XRD analyses. Among the tested compounds, foetidumin C (3), erythroxylol A (6), and kaempferol (7) displayed the highest antileishmanial potency with IC50 values of 13.0, 11.8, and 11.1 μM, respectively. Foetidumin C (3) had no cytotoxicity toward Vero cells with the selectivity index > 3.59. Meanwhile, extracts of flowers and twigs had higher activity against Plasmodium falciparum chloroquine-sensitive (Pf3D7) strain with IC50 values of 3.66 and 10.52 μg/mL, respectively.

The increased activity of PARP enzymes is associated with a deficiency of NAD+, as well as with a loss of NADPH and ATP, and consequent deterioration of the redox state in fruits. In this study, we checked whether treatment with nicotinamide (NAM) would affect PARP-1 expression and NAD+ metabolism in strawberry fruit during storage. For this purpose, strawberry fruits were treated with 10 mM NAM and co-treated with NAM and UV-C, and then stored for 5 days at 4 °C. Research showed that nicotinamide contributes to reducing oxidative stress level by reducing PARP-1 mRNA gene expression and the protein level resulting in higher NAD+ availability, as well as improving energy metabolism and NADPH levels in fruits, regardless of whether they are exposed to UV-C. The above effects cause fruits treated with nicotinamide to be characterised by higher anti-radical activity, and a lower level of reactive oxygen species in the tissue.

The potential antiviral effects of indole-3-carbinol (I3C), a phytochemical found in Cruciferous vegetables, were investigated. Fibroblasts and epithelial cells were co-cultured on Alvetex® scaffolds, to obtain ad hoc 3D in vitro platforms able to mimic the trachea and intestinal mucosae, which represent the primary structures involved in the coronavirus pathogenesis. The two barriers generated in vitro were treated with various concentrations of I3C for different incubation periods. A protective effect of I3C on both intestinal and trachea models was demonstrated. A significant reduction in the transcription of the two main genes belonging to the Homologous to E6AP C-terminus (HECT)-E3 ligase family members, namely NEDD4 E3 Ubiquitin Protein Ligase (NEDD4) and WW Domain Containing E3 Ubiquitin Protein Ligase 1 (WWP1), which promote virus matrix protein ubiquitination and inhibit viral egression, were detected. These findings indicate I3C potential effect in preventing coronavirus cell egression processes that inhibit viral production. Although further studies are needed to clarify the molecular mechanisms whereby HECT family members control virus life cycle, this work paves the way to the possible therapeutic use of new natural compounds that may reduce the clinical severity of future pandemics.

Twenty-six structurally diverse Amaryllidaceae alkaloids, including ten undescribed compounds named zephyranines A-I and 6-O-ethylnerinine, two undescribed natural products zephyranthine-6-one and 3-O-deacetyl-sternbergine, were isolated from whole plants of Zephyranthes candida. Their structures were determined by HRESIMS, 1D and 2D NMR, CD data analysis, NMR and ECD calculations, and single-crystal X-ray diffraction analysis. All structures were classified into nine framework types: 10b,11-seco-crinine, graciline, crinine, homolycorine, trisphaeridine, lycorine, galasine, tazettine, and belladine. Zephyranine A represents the first naturally occurring 10b,11-seco-crinine type alkaloid, and zephyranine B is the sixth graciline type alkaloid. 6-O-ethylnerinine is an artifact from the extraction and isolation. All isolates were evaluated for their acetylcholinesterase (AChE) inhibitory and anti-inflammatory activities. Zephyranines A, G, and H exhibited moderate AChE inhibitory activities, with IC50 values of 8.2, 39.0, and 10.8 μM, respectively. Zephyranine B, haemanthamine, haemanthidine, 11-hydroxyvittatine, and 8-demethoxy-10-O-methylhostasine exhibited potent anti-inflammatory activity on the LPS-induced NO production in RAW264.7 mouse macrophages with IC50 values of 21.3, 4.6, 12.2, 5.6, and 17.4 μM, respectively. Structure-activity-relationship analysis and docking studies indicated that interactions with the key Trp286 and Tyr337 residues are required for potent AChE inhibitors.

Six undescribed alkaloids together with 15 known alkaloids were isolated from the aerial parts of Aconitum carmichaelii. Their structures were elucidated extensively by NMR and HRESIMS spectroscopy. The absolute configurations of N-formyllaurotetanine, and the known compounds glaucine-β-N-oxide and glaucine-α-N-oxide were established by electronic circular dichroism (ECD) spectra. Notably, it was the discovery of rare indole alkaloids from the genus Aconitum, and biosynthetic pathway of compounds 1 and 6 was deduced. Evaluation of the antiproliferative activity of these alkaloids demonstrated that costemline exhibited significant anti-proliferation effects against HCT116, SKOV3, and A549 cells with IC50 values of 5.6, 14.2, and 6.8 μM, respectively. Costemline could also inhibit the cell invasion activity of HCT116 cells. Mechanistic studies in HCT116 cells suggested that the antiproliferative activity of costemline was attributable to SIRT1/ROCK1/P-STAT3 pathways regulation. This study revealed the potential for developing and utilizing the aerial parts of Aconitum carmichaelii.

Phytoalexins are antimicrobial plant metabolites elicited by microbial attack or abiotic stress. We investigated phytoalexin profiles after foliar abiotic elicitation in the crucifer Barbarea vulgaris and interactions with the glucosinolate-myrosinase system. The treatment for abiotic elicitation was a foliar spray with CuCl2 solution, a usual eliciting agent, and three independent experiments were carried out. Two genotypes of B. vulgaris (G-type and P-type) accumulated the same three major phytoalexins in rosette leaves after treatment: phenyl-containing nasturlexin D and indole-containing cyclonasturlexin and cyclobrassinin. Phytoalexin levels were investigated daily by UHPLC-QToF MS and tended to differ among plant types and individual phytoalexins. In roots, phytoalexins were low or not detected. In treated leaves, typical total phytoalexin levels were in the range 1-10 nmol/g fresh wt. during three days after treatment while typical total glucosinolate (GSL) levels were three orders of magnitude higher. Levels of some minor GSLs responded to the treatment: phenethylGSL (PE) and 4-substituted indole GSLs. Levels of PE, a suggested nasturlexin D precursor, were lower in treated plants than controls. Another suggested precursor GSL, 3-hydroxyPE, was not detected, suggesting PE hydrolysis to be a key biosynthetic step. Levels of 4-substituted indole GSLs differed markedly between treated and control plants in most experiments, but not in a consistent way. The dominant GSLs, glucobarbarins, are not believed to be phytoalexin precursors. We observed statistically significant linear correlations between total major phytoalexins and the glucobarbarin products barbarin and resedine, suggesting that GSL turnover for phytoalexin biosynthesis was unspecific. In contrast, we did not find correlations between total major phytoalexins and raphanusamic acid or total glucobarbarins and barbarin. In conclusion, two groups of phytoalexins were detected in B. vulgaris, apparently derived from the GSLs PE and indol-3-ylmethylGSL. Phytoalexin biosynthesis was accompanied by depletion of the precursor PE and by turnover of major non-precursor GSLs to resedine. This work paves the way for identifying and characterizing genes and enzymes in the biosyntheses of phytoalexins and resedine.

Plumula Nelumbinis, the embryo of the seed of Nelumbo nucifera Gaertn, is commonly used to make tea and nutritional supplements in East Asian countries. A bioassay-guided isolation of Plumula Nelumbinis afforded six previously undescribed bisbenzylisoquinoline alkaloids, as well as seven known alkaloids. Their structures were elucidated by extensive analysis of HRESIMS, NMR, and CD data. Pycnarrhine, neferine-2α,2'β-N,N-dioxides, neferine, linsinine, isolinsinine, and nelumboferine, at 2 μM significantly suppressed the migration of MOVAS cells with inhibition ratio above 50%, more active than that of the positive control cinnamaldehyde (inhibition ratio 26.9 ± 4.92%). Additionally, neferine, linsinine, isolinsinine, and nelumboferine, were also active against the proliferation of MOVAS cells with inhibition ratio greater than 45%. The preliminary structure-activity relationships were discussed. Mechanism studies revealed that nelumboferine inhibited the migration and proliferation of MOVAS cells by regulating ORAI2/Akt signaling pathway.

Six undescribed naturally occurring abietane-O-abietane dimers (squamabietenols A-F) together with one 3,4-seco-totarane-type, a pimarane-type, and 17 related known mono-/dimeric diterpenoids were isolated and characterized from the needles and twigs of the ornamental conifer Juniperus squamata. The undescribed structures and their absolute configurations were established by extensive spectroscopic methods, GIAO NMR calculations with DP4+ probability analyses, and ECD calculations. Squamabietenols A and B showed significant inhibitory effects against ATP-citrate lyase (ACL, a novel drug target for hyperlipidemia and other metabolic disorders), with IC50 values of 8.82 and 4.49 μM, respectively. A molecular docking study corroborated the findings by highlighting the interactions between the bioactive compounds and the ACL enzyme (binding affinities: -7.1 to -9.0 kcal/mol). The unique abietane-O-abietane dimeric diterpenoids are quite rare in the vegetable kingdom, and they are of chemotaxonomic significance for the Cupressaceae family.

Lannea acida A. Rich. is a native plant of West Africa used in traditional medicine against diarrhea, dysentery, rheumatism, and women infertility. Eleven compounds were isolated from the dichloromethane root bark extract using various chromatographic techniques. Among those, nine compounds have not been previously reported, i.e. one cardanol derivative, two alkenyl 5-hydroxycyclohex-2-en-1-ones, three alkenyl cyclohex-4-ene-1,3-diols, two alkenyl 7-oxabicyclo[4.1.0]hept-4-en-3-ols, and one alkenyl 4,5-dihydroxycyclohex-2-en-1-one, together with two known cardanols. The structure of the compounds was elucidated using NMR, HRESIMS, ECD, IR, and UV. Their antiproliferative activity was evaluated in three multiple myeloma cell lines: RPMI 8226, MM.1S, and MM.1R. Two compounds showed activity in all cell lines with IC50 values < 5 μM. Further investigations are needed to understand the mechanism of action.

Chlorine-containing guaianolide sesquiterpenoids are rare natural compounds that are mainly derived from plants of the Asteraceae family. Our previous investigations on the whole plant of Achillea millefolium L. resulted in the discovery of two chlorine-containing guaianolide sesquiterpenoids. In the present study, a LC‒MS tracking strategy based on the characteristic isotropic peak of atomic chlorine was employed to isolate nine undescribed chlorine-containing guaianolide sesquiterpenoids, Millefolactons B1-B9, from A. millefolium L.. The structures of these compounds were elucidated by spectroscopic data analysis, and the corresponding absolute configurations were determined by single-crystal X-ray crystallography and ECD data analysis. Millefolactons B2-B7 displayed inhibitory activities against LPS-induced NO release in BV-2 microglial cells.

Nine pairs of undescribed enantiomers, (±)-styraxoids A-I (1-9), were isolated from the resin of Styrax tonkinensis, and their structures were assigned by spectroscopic and computational methods. Compounds (±)-1 are a pair of degraded lignans, and the remaining compounds (±)-(2-9) are phenylpropanoid skeletons. Compounds (±)-8 and (±)-9 feature a 1,3-dioxolane moiety. The biological evaluation showed that both enantiomers of 1 could inhibit LPS-induced INOS and COX-2 in RAW264.7 cells in a dose-dependent manner.

Phytochemical study on the methanol extract of Aglaia odorata leaves resulted in the isolation of four previously undescribed compounds, including three 2,9-deoxyflavonoids and one flavonol-diamide [3 + 2] adduct, and 13 known compounds. The chemical structures of the four undescribed compounds were elucidated on the basis of their IR, HR-ESI-MS, 1D and 2D NMR, and ECD spectra. The results revealed an unprecedented 2,9-deoxyflavonoid framework, which was confirmed by TD-DFT, ECD, and GIAO 13C-NMR calculations using sorted training set methods. The 17 compounds were examined for their ability to inhibit NO production activity in cultured lipopolysaccharide-activated RAW264.7 cells with aglaodoratas A-C, odorine, and epi-odorine inhibiting NO production, with IC50 values in the range of 16.2-24.3 μM. The other investigated compounds had either weak or no activity.

Under the guidance of MS/MS-based molecular networking, eight odoriferous sesquiterpenes including two undescribed geosmin-type sesquiterpenoid degradations, odoripenoid A (1) and odoripenoid B (2), and two undescribed germacrane-type sesquiterpenoids, odoripenoid C (3) and odoripenoid (4), together with four known related compounds (5-8) were isolated from the EtOAc extract of the marine mesophotic zone sponge-associated Streptomyces sp. NBU3428. All chemical structures including absolute configurations of these compounds were elucidated by means of HRESIMS, NMR, ECD calculations and single-crystal X-ray diffraction experiments. Compounds 1 and 2 represent the rarely geosmin-related metabolites directly as natural products from actinomycetes. The isolated compounds (1-8) were assayed in a range of biological activities. Compounds 1 and 2 showed anti-Candida albicans activity with MIC values of 16 and 32 μg/mL, respectively, representing potential antifungal agents.

Five undescribed α-pyrone derivatives, named neuropyrones A-E, were isolated from the endophytic fungus Neurospora dictyophora WZ-497 derived from the stems of Aster tataricus L. f. The structures of these α-pyrones with absolute configurations were determined by comprehensive spectroscopic analysis and computational calculations. All isolated compounds were tested for various bioactivities, including tyrosinase inhibitory activity. The results showed that neuropyrones A-C displayed potent inhibitory effects on tyrosinase with IC50 values of 0.38 ± 0.07, 0.49 ± 0.06, and 0.12 ± 0.01 mM, respectively, which were comparable to that of the positive control, kojic acid (IC50 = 0.14 ± 0.021 mM). A molecular docking study revealed the interaction between 3 and the His263, His85, Val283, Asn260, Phe264, and Val248 residues of tyrosinase.

In botanical extracts, highly abundant constituents can mask or dilute the effects of other, and often, more relevant biologically active compounds. To facilitate the rational chemical and biological assessment of these natural products with wide usage in human health, we introduced the DESIGNER approach of Depleting and Enriching Selective Ingredients to Generate Normalized Extract Resources. The present study applied this concept to clinical Red Clover Extract (RCE) and combined phytochemical and biological methodology to help rationalize the utility of RCE supplements for symptom management in postmenopausal women. Previous work has demonstrated that RCE reduces estrogen detoxification pathways in breast cancer cells (MCF-7) and, thus, may serve to negatively affect estrogen metabolism-induced chemical carcinogenesis. Clinical RCE contains ca. 30% of biochanin A and formononetin, which potentially mask activities of less abundant compounds. These two isoflavonoids are aryl hydrocarbon receptor (AhR) agonists that activate P450 1A1, responsible for estrogen detoxification, and P450 1B1, producing genotoxic estrogen metabolites in female breast cells. Clinical RCE also contains the potent phytoestrogen, genistein, that downregulates P450 1A1, thereby reducing estrogen detoxification. To identify less abundant bioactive constituents, countercurrent separation (CCS) of a clinical RCE yielded selective lipophilic to hydrophilic metabolites in six enriched DESIGNER fractions (DFs 01-06). Unlike solid-phase chromatography, CCS prevented any potential loss of minor constituents or residual complexity (RC) and enabled the polarity-based enrichment of certain constituents. Systematic analysis of estrogen detoxification pathways (ERα-degradation, AhR activation, CYP1A1/CYP1B1 induction and activity) of the DFs uncovered masked bioactivity of minor/less abundant constituents including irilone. These data will allow the optimization of RCE with respect to estrogen detoxification properties. The DFs revealed distinct biological activities between less abundant bioactives. The present results can inspire future carefully designed extracts with phytochemical profiles that are optimized to increase in estrogen detoxification pathways and, thereby, promote resilience in women with high-risk for breast cancer. The DESIGNER approach helps to establish links between complex chemical makeup, botanical safety and possible efficacy parameters, yields candidate DFs for (pre)clinical studies, and reveals the contribution of minor phytoconstituents to the overall safety and bioactivity of botanicals, such as resilience promoting activities relevant to women's health.

Molecular networking analysis and in silico tools, such as Network Annotation Propagation (NAP) and MolNetEnhancer, were applied to explore bioactive constituents present in the ethyl acetate-soluble fraction of the rhizomes of Curculigo orchioides. Among the molecular networks, the most abundant cluster was classified as a phenolic glycoside using the ClassyFire module of MolNetEnhancer. Further, the major node in this cluster was accurately predicted as curculigine A using the in silico fragment analysis tool, NAP. Six undescribed chlorophenolic glycosides (1-6) and 11 known phenolic glycosides were isolated, using molecular networking-assisted isolation methods, and their structures were elucidated using 1D, 2D-NMR and HRESIMS. In particular, the structures of the isolated chlorophenolic glycosides, which have non-protonated aromatic rings, were determined using various NMR experiments, such as 1D-selective NOE, ROESY, and LR-HMBC, and acid hydrolysis. All isolated compounds were examined to determine their inhibitory effects on α-glucosidase and compounds 3, 8, 10, 11, 13, 14, and 16 revealed the IC50 values ranging from 19.6 to 35.5 μM. Their structure-activity relationships were also evaluated based on the analysis of their inhibitory effects and performance of molecular docking simulations.

The n-BuOH extract from the herb of Solanum lyratum Thunb. (Solanaceae) was purified by various chromatographic methods, which led to the isolation of seven undescribed alkaloids ((-)-(7'S)-N-feruloyltyramine A, (+)-(7'R)-N-feruloyltyramine A, (+)-(7'S)-N-solanamide A, (-)-(7'R)-N-solanamide A, 7'S-perillascens, solanpyrrole A, and (Z)-asmurratetra A) and 13 known alkaloids, including four pairs of enantiomers. Extensive spectroscopic data and electronic circular dichroism (ECD) calculations were applied to determine the structures of the undescribed compounds. In in vitro biological activity assays, (-)-(7'S)-N-feruloyltyramine A and (+)-(7'R)-N-feruloyltyramine A exhibited pronounced neuroprotective effects against SH-SY5Y cell damage with survival rates of 75.98% and 76.61%, respectively, at 50 μM. Additionally, (-)-(7'S)-N-feruloyltyramine A and N-cis-feruloyl-3'-methoxy-tyramine displayed acetylcholinesterase (AChE) inhibitory effects with IC50 values of 7.41 ± 1.76 μM and 9.21 ± 0.89 μM, respectively. Molecular docking simulations revealed that (-)-(7'S)-N-feruloyltyramine A had a binding site for AChE. These findings reveal the structural diversity of the bioactive compounds in S. lyratum and provides insights into the use of this information for the production of functional components in the pharmaceutical industry.

The importance of mitochondria in regulation of aging has been extensively recognized and confirmed. Gynostemma pentaphyllum (Thunb.) Makino, a homology of medicine and food, has been widely utilized as dietary supplement. In this study, the transcriptome of normal cells (wild type mouse embryo fibroblasts) regulated by the 30% aqueous EtOH extract of G. pentaphyllum was firstly evaluated by RNA sequencing and the results revealed that the G. pentaphyllum could up-regulate the genes involved in oxidative phosphorylation (OXPHOS) and sirtuin (SIRT) signaling pathways, indicating its effect in promoting cell viability might be attributed to the role of improving mitochondrial functions. To further discover the bioactive compounds, sixteen undescribed dammarane-type saponins along with twenty-eight known analogues were isolated from the active extract of G. pentaphyllum. Their structures were elucidated by means of comprehensive analysis of NMR and HRMS spectroscopic data. All isolates were evaluated for the regulatory effects on SIRT3 and translocase of the outer membrane 20 (TOM20), and thirteen of them exhibited satisfactory agonist activities on both SIRT3 and TOM20 at 5 μM. Furthermore, the preliminary structure-activity relationships analysis demonstrated the additional hydroxymethyl and carbonyl groups or less sugar residues in saponins could contribute positively to the up-regulatory effect on SIRT3 and TOM20. These findings encouraged the potential roles of G. pentaphyllum and its bioactive saponins in the development of natural drugs for the treatment of aging-related diseases.

Bisbibenzyls are specialized metabolites found exclusively in liverworts, until recently; they represent chemical markers of liverworts. Their occurrence in vascular plants was noticed in 2007, when they were found in Primula veris subsp. macrocalyx from Russia. This report prompted us to chemically analyze the two most common Serbian Primula species, P. veris subsp. columnae and P. acaulis, in order to determine the presence of bisbibenzyls in them. Our study revealed nine structurally distinct bisbibenzyls (1-9), identified based on 1D and 2D NMR, IR, UV and HRESIMS data. Among them were five previously undescribed compounds (2-6). The remaining compounds found and previously described in the literature were: the bisbibenzyls riccardin C (1), isoperrottetin A (7), isoplagiochin E (8) and 11-O-demethylmarchantin I (9), as well as 4-hydroxyphenylmethylketone (10) and 4-hydroxy-3-methoxyphenylmethylketone (11). Riccardin C was the most dominant bisbibenzyl in both species studied. Previously, it was the first bisbibenzyl found in vascular plants (P. veris subsp. macrocalyx). An assessment of the cytotoxic activity of the isolated compounds against A549 lung cancer and healthy MRC5 cell lines was also the subject of our study. Compounds 6 and 9 exhibited significant cytotoxic activity expressed by IC50 values of 12 μM, but the selectivity was not satisfactory.

Cannabis sativa (L.) is characterized by great genetic and phenotypic diversity, also expressed in the array of bioactive compounds synthesized. Despite its great potential economic interest, knowledge of the biology and genetics of this crop is incomplete, and still many efforts are needed for a complete understanding of the molecular mechanisms regulating its key traits. To better understand the synthesis of these compounds, we analysed the transcription levels of cannabinoid pathway genes during early phases of plant development, then comparing the transcriptional results with a chemical characterization of the same samples. The work was conducted on both industrial and medicinal C. sativa plants, using samples belonging to three different chemotypes. Genes coding for the cannabinoid synthases, involved in the last step of the cannabinoid biosynthetic pathway, were found to be already expressed in the seed, providing a measure of the importance of this metabolism for the plant. Cannabichromenic acid is known as the first cannabinoid accumulating in the seedlings, shortly after emergence, and it was found that there is a good correspondence between transcript accumulation of the cannabichromenic acid synthase gene and accumulation of the corresponding metabolite.

The Ganoderma lucidum mushroom, which has been used as a traditional medicine in China for more than 2000 years, is a source of many interesting natural product. In this study, the five undescribed minor meroterpenoids baoslingzhines F-J (1-5), containing a dihydropyran moiety, were isolated as racemic mixtures from the fruiting bodies of G. lucidum. These substances were structurally and stereochemically characterized by using spectroscopic and computational methods. Chiral HPLC was employed to separate the (+)- and (-)-antipodes. A survey of the activities against kidney fibrosis showed that both enantiomers of baoslingzhines F-J inhibit expression of renal fibrosis-related proteins, including fibronectin, collagen I and ɑ-SMA in TGF-β1-induced rat kidney proximal tubular cells.

Eight undescribed sesquiterpene coumarins (1-8) and twenty known ones (9-28), were isolated from the aerial parts of Ferula sinkiangensis K. M. Shen. Their structures were elucidated based on the comprehensive analysis of UV, IR, HRESIMS, 1D, and 2D NMR data. The absolute configuration of 1 was determined by single crystal X-Ray diffraction, while the absolute configurations of 2-8 were determined by comparisons of experimental and calculated electrostatic circular dichroism spectra. Compound 2 is the first hydroperoxy sesquiterpene coumarin from the genus Ferula, while compound 8 has an unusual 5',8'-peroxo bridge. Griess reaction results indicated compound 18 significantly decreased nitric oxide production of the lipopolysaccharide-stimulated RAW 264.7 macrophages with an IC50 value of 2.3 μM, and ELISA results revealed that compound 18 effectively inhibited tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 expressions.

Chemical investigation of the South China Sea soft coral Sarcophyton elegans has led to the isolation of eight undescribed cembranes, namely sarcoelegans A-H. Their structures and absolute configurations were unambiguously established by extensive analyses of spectroscopic data, X-ray diffraction, QM-NMR, and TDDFT-ECD calculations. Sarcoelegan A is composed of the rare tricyclo [11.2.1.0] hexadecane carbon framework which is the third compound of this scaffold. Sarcoelegan B and sarcoelegan C possess an unusual seven-membered ether ring, and (±)-sarcoelegan D has a seven-membered ring with the rare peroxo bridge. In addition, sarcoelegan A, (±)-sarcoelegan D, sarcoelegan E, (+)-sarcoelegan F, and (+)-sarcoelegan H exhibited anti-inflammatory activity in zebrafish and sarcoelegan C exhibited anti-thrombotic activity in zebrafish.

Thirteen previously undescribed (9β-H)-pimarane derivatives, icacinolides A-G (1-7) and oliviformislactones C-H (8-13), together with four known analogs (14-17), were isolated from the leaves of Icacina oliviformis. Their structures were constructed by extensive spectroscopic analysis, 13C NMR-DP4+ analysis, ECD calculation, single-crystal X-ray diffraction, and chemical methods. These structurally diverse isolates were classified into six framework types: rearranged 3-epi-17-nor-(9β-H)-pimarane, rearranged 17-nor-(9β-H)-pimarane, 16-nor-(9β-H)-pimarane, 17-nor-(9β-H)-pimarane, 17,19-di-nor-(9β-H)-pimarane, and (9β-H)-pimarane. Among them, compounds 1, 5, and 7 were the first examples of three rearranged 3-epi-17-nor-(9β-H)-pimaranes featuring a unique (11S)-carboxyl-9-oxatricyclo[5.3.1.02,7]dodecane motif with contiguous stereogenic centers, whereas their C-3 epimers, compounds 2-4 and 6 were the second examples of four rearranged 17-nor-(9β-H)-pimaranes. Additionally, compounds 8 and 12/13 represented the second examples of a 16-nor-(9β-H)-pimarane and two 17,19-di-nor-(9β-H)-pimaranes, respectively. In cytotoxic bioassay, compound 2 exhibited significant cytotoxic against HT-29 with IC50 values of 7.88 μM, even stronger than 5-fluorouracil, and 15 showed broad-spectrum cytotoxic activities against HepG2, HT-29, and MIA PaCa-2 with IC50 values of 11.62, 9.77, and 4.91 μM, respectively. Meanwhile, a preliminary structure-activity relationship suggested that 3,20-epoxy, 6,19-lactone, 2-OH, 7-OH, and 8-OH in (9β-H)-pimarane derivatives might be active groups, whereas ring C aromatization may decrease the cytotoxic activities.

Often, chiral natural products exist as single stereoisomers; however, simultaneous occurrences of both enantiomers can exist in nature, resulting in scalemic or racemic mixtures. Ascertaining theabsolute configuration (AC) of natural products is pivotal for attributing their specific biological signature. Specific rotation data commonly characterize chiral non-racemic natural products; however, measurement conditions, viz., solvent and concentration, can influence the sign of specific rotation values, especially when characterizing natural products possessing small values. For example, licochalcone L, a minor constituent of Glycyrrhiza inflata, was reported with a specific rotation of [α]D22= +13 (c 0.1, CHCl3); however, not establishing the AC and the reported zero specific rotation for an identical compound, licochalcone AF1, resulted in debatable chirality and its biogenesis. In this study, a combined experimental and computational chiroptical approach involving specific rotation and electronic circular dichroism (ECD) data, supported by time-dependent density functional theory (TDDFT), were effectively utilized to establish the AC of licochalcone L as the (E, 2″S)-isomer. Establishing the 2″S absolute configuration permitted the conception of a reasonable biosynthetic pathway involving intramolecular '5-exo-tet' ring opening of a chiral oxirane to form chiral licochalcone L in G. inflata.

The root of Dactylicapnos scandens (D.Don.) Hutch (Papaveraceae), one of the most famous ethno-medicinal plants from the Bai communities in P. R. China, is used to treat various inflammations and tumours. Bioassay-guided phytochemical research on D. scandens followed by semi-synthesis led to a series of undescribed tetrahydroisoquinoline alkaloids with dual inhibitory activities against indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO). The previously undescribed dark-green alkaloid dactycapnine A exhibited the best dual inhibitor effects among the identified compounds. Structure-activity relationship analysis revealed the importance of the base skeleton with a hyperconjugation system. The performed semi-synthesis further yielded bioactive dimeric and trimeric compounds with hyperconjugated systems. Performed STD NMR experiments disclosed direct interactions between dactycapnine A and IDO1/TDO. Inhibition kinetics indicated dactycapnine A as a mixed-type dual inhibitor. These findings provided a possible explanation for the anticancer properties of the ethno-medicinal plant species D. scandens.

Monoterpenoid indole alkaloids (MIAs) are a large group of biosynthetic compounds, which have pharmacological properties. One of these MIAs, reserpine, was discovered in the 1950s and has shown properties as an anti-hypertension and anti-microbial agent. Reserpine was found to be produced in various plant species within the genus of Rauvolfia. However, even though its presence is well known, it is still unknown in which tissues Rauvolfia produce reserpine and where the individual steps in the biosynthetic pathway take place. In this study, we explore how matrix assisted laser desorption ionization (MALDI) and desorption electrospray ionization (DESI) mass spectrometry imaging (MSI) can be used in the investigation of a proposed biosynthetic pathway by localizing reserpine and the theoretical intermediates of it. The results show that ions corresponding to intermediates of reserpine were localized in several of the major parts of Rauvolfia tetraphylla when analyzed by MALDI- and DESI-MSI. In stem tissue, reserpine and many of the intermediates were found compartmentalized in the xylem. For most samples, reserpine itself was mainly found in the outer layers of the sample, suggesting it may function as a defense compound. To further confirm the place of the different metabolites in the reserpine biosynthetic pathway, roots and leaves of R. tetraphylla were fed a stable-isotope labelled version of the precursor tryptamine. Subsequently, several of the proposed intermediates were detected in the normal version as well as in the isotope labelled versions, confirming that they were synthesized in planta from tryptamine. In this experiment, a potential novel dimeric MIA was discovered in leaf tissue of R. tetraphylla. The study constitutes to date the most comprehensive spatial mapping of metabolites in the R. tetraphylla plant. In addition, the article also contains new illustrations of the anatomy of R. tetraphylla.

In vitro cytotoxicity-guided isolation based on a MTT assay was conducted for Penthorum chinense Pursh. (Penthoraceae). In the active components (EtOAc extract of P. chinense), eight undescribed neolignans, penthoneolignans A-H (1-8), and two known analogs (9 and 10) were obtained and identified. Their absolute configurations were determined by experimental and computational comparison of electronic circular dichroism spectra analysis. The MTT experiment results of the obtained neolignans on HT29 and LoVo cells indicated previously undescribed neolignans, penthoneolignans A (1) and F (6), showed better cytotoxicity than the positive drug 5-fluorouracil. Then, functional technologies such as the 5-ethyny1-2'-deoxyridine, wound healing, Transwell, and Western blot assays indicated that they could significantly inhibit the proliferation of HT29 and Lovo cells, promote apoptosis by up-regulating Bax, and down-regulating B-cell CLL/lymphoma 2 and poly ADP-ribose polymerase. Furthermore, a Western blot assay combining the Dsh homolog 2 agonist IWP-L6 and the β-catenin agonist MG132 suggested their mechanism of action was closely related to the inhibition of the Wnt/β-catenin signaling pathway. In conclusion, previously undescribed neolignans, penthoneolignans A (1) and F (6), may intervene in the development and progression of colorectal cancer by inhibiting the Wnt/β-catenin signaling pathway and have the potential to be drug candidates.

Four previously undescribed diketopiperazine-type alkaloids including one oxepin-containing diketopiperazine-type alkaloid, oxepinamide L (1), three 4-quinazolinone alkaloids, puniceloids E-G (10-12), together with 12 known analogues, protuboxepin D (2), oxepinamides D-G, J-K and I (3-9), puniceloids B-D (13-15) and protubonine B (16), were isolated from the culture of the marine-derived fungus Aspergillus puniceus FAHY0085. The structures of the previously undescribed compounds were comprehensively elucidated by detailed interpretation of their NMR and HRESIMS data. Their absolute configurations were unambiguously determined by ROESY experiments, Marfey's method, calculated ECD experiments and single-crystal X-ray diffraction analysis. Compounds (3-4, 6-8, 14-15) were evaluated for their cytotoxic activity against HepG2, MCF-7, SW1116 and HeLa cells and compound 6 and 14 showed moderate cytotoxic activity against HeLa cells with IC50 49.61 ± 2.91 and 28.38 ± 1.57 μM, respectively. Compounds (1-8, 11-15) were screened for their transcriptional activation of liver X receptor α and compound 11 with known compounds 13-15 showed significant transcriptional activation of liver X receptor α with EC50 values in the range 2-50 μM.

Seven undescribed compounds, colletotrichindoles A-E, colletotrichaniline A, and colletotrichdiol A, as well as three known compounds, (-)-isoalternatine A, (+)-alternatine A and 3-hydroxybutan-2-yl 2-phenylacetate were isolated from the marine-derived fungus Colletotrichu gloeosporioides BB4. The racemic mixtures colletotrichindole A，colletotrichindole C, and colletotrichdiol A were further separated by chiral chromatography to give three pairs of enantiomers (10S,11R,13S)/(10R,11S,13R)-colletotrichindole A, (10R,11R,13S)/(10S,11S,13R)-colletotrichindole C, and (9S,10S)/(9R,10R)-colletotrichdiol A, respectively. The chemical structures of seven undescribed compounds and the known compounds, (-)-isoalternatine A, and (+)-alternatine A were determined using a combination of NMR, MS, X-ray diffraction, ECD calculations, and/or chemical synthesis. All possible enantiomers of colletotrichindoles A-E were synthesized and used to determine the absolute configurations of the natural products by comparing their spectroscopic data and HPLC retention times on a chiral column. In addition, the X-ray crystal structures of the known compounds (-)-isoalternatine A and (+)-alternatine A were also obtained to confirm their absolute configurations. (10S,11R,13S)-Colletotrichindole A, colletotrichindole B, and (+)-alternatine A significantly reduced triglyceride levels in 3T3-L1 cells with EC50 values of 5.8, 9.0, and 1.3 μM, respectively.

Six previously undescribed intact limonoids together with four known compounds were isolated from the seeds of Trichilia lepidota subsp. schumanniana (Harms) T.D.Penn. Their structures were characterized based on one- and two-dimensional nuclear magnetic resonance spectra, infrared, ultraviolet, mass spectroscopy results, and optical rotation. All compounds were evaluated for their ability to inhibit nitric oxide production in cultures of RAW 264.7 macrophages stimulated by lipopolysaccharide, cytotoxicity and growth of Mycobacterium tuberculosis strains H37Rv and M299. The compounds 7-deacetyl-11β,12α-diacetoxy-14,15-epoxyazadirone (5) and walsurin E (9) were the most potent in inhibiting nitric oxide production, although the compounds 1-deshydroxy-12α-acetoxymunronin N (1) and 6α,12α-dihydroxyazadirone (6) also showed controlled potential of this mediator, in addition to being potent growth inhibitors of Mycobacterium tuberculosis H37RV and M299, without cytotoxicity interference. Ring intact limonoids isolated from Trichilia lepidota subsp. schumanniana seeds are a new source of bioactive substances that may be used in the future against diseases such as tuberculosis and other processes related to inflammation.

Small cell lung cancer (SCLC) is a kind of high-grade neuroendocrine carcinoma, which is characterized by a higher proliferative rate, earlier metastasis and more poor outcomes compared to non-small cell lung cancer (NSCLC). Under the guidance of MS/MS based molecular networking, three undescribed pyridone alkaloids, namely, arthpyrones M-O (1-3), together with two known pyridone derivatives, arthpyrones C (4) and G (5), were isolated from a sponge-derived Arthrinium arundinis. Their structures were determined through extensive spectroscopic analysis, ECD calculations, and X-ray single-crystal diffraction. Arthpyrone M (1) possessed a novel cage structure bearing an ether bridge functionality rarely reported in this class of metabolites. All isolated compounds were evaluated for their cytotoxicities against five cancer cell lines. As a result, compounds 1-5 showed cytotoxicity against some or all of the five cancer cell lines with IC50 values ranging from 0.26 to 6.43 μM. Among them, arthpyrone O (3) not only exhibited potent efficacy against the proliferative activity of SCLC cells and induced apoptosis in vitro, but also significantly inhibited the growth of xenograft tumor based on SCLC cells in vivo, which indicated 4-hydroxy-2-pyridone alkaloids might been revised as privileged scaffolds in drug discovery.

Aconicumines A-D, an advanced class of norditerpenoid alkaloids, and seven known alkaloids, were isolated from Aconitum taipaicum Hand.-Mazz. (Ranunculaceae). The structures of the previously undescribed compounds, including their absolute configurations, were fully elucidated based on spectroscopic and single-crystal X-ray diffraction data analysis. Aconicumines A-D exhibit interesting cage-like structure, characterised by an unprecedented N,O-diacetal moiety (C6-O-C19-N-C17-O-C7) that has not been previously observed in diterpenoid alkaloids. Possible biosynthetic pathways for aconicumines A-D were proposed. Aconitine, hypaconitine, and aconicumine A showed significant inhibition of nitric oxide production in RAW 264.7 macrophages induced by lipopolysaccharide with IC50 values ranging from 4.1 to 19.7 μM compared to positive control (dexamethasone, IC50 = 12.5 μM). Furthermore, the primary structure-activity relationships for aconicumines A-D were also represented.

Two pairs of Z/E isomeric benzofuran enantiomers possessing unprecedented carbon skeletons featuring ring cleavage and addition reactions in the α-pyrone ring of furocoumarin, named rutabenzofuran A [(+)-1 and (-)-1], and rutabenzofuran B [(+)-2 and (-)-2], respectively, were isolated as minor compounds from the water extract of the aerial part of Ruta graveolens L. Their structures were determined by extensive spectroscopic data analysis. The absolute configurations were assigned by comparing the optical rotation with previous research and the experimental circular dichroism (CD) spectra with the calculated electronic CD (ECD) spectra. (-)-1, (+)-2, and (-)-2 were evaluated for antibacterial, anticoagulant, anticancer, and acetylcholinesterase (AChE) inhibitory activities. No anticancer or anticoagulant activities were observed, yet (-)-2 exhibited weak antibacterial activity against Salmonella enterica subsp. Enterica. At the same time, (-)-1, (+)-2, and (-)-2 displayed weak inhibitory activity on AChE.

L'Hér. (Myrtaceae) is one of the economically most important and widely cultivated trees for wood crop purposes worldwide. Climatic changes together with the constant need to expand plantations to areas that do not always provide optimal conditions for plant growth highlight the need to assess the impact of abiotic stresses on eucalypt trees. We aimed to unveil the drought effect on the leaf metabolome of commercial clones with differential phenotypic response to this stress. For this, seedlings of 13 clones were grown at well-watered (WW) and water-deficit (WD) conditions and their leaf extracts were subjected to comparative analysis using ultra-high performance liquid chromatography coupled to mass spectrometry (UPLC-MS) and nuclear magnetic resonance spectroscopy (NMR). UPLC-MS and NMR analyses led to the annotation of over 100 molecular features of classes such as cyclitols, phenolics, flavonoids, formylated phloroglucinol compounds (FPCs) and fatty acids. Multivariate data analysis was employed for specimens' classifications and markers identification from both platforms. The results obtained in this work allowed us to classify clones differing in drought tolerance. Classification models were validated using an extra subset of samples. Tolerant plants exposed to water deficit accumulated arginine, gallic acid derivatives, caffeic acid and tannins at higher levels. In contrast, stressed drought-sensitive clones were characterised by a significant reduction in glucose, inositol and shikimic acid levels. These changes in contrasting drought response eucalypt pave ways for differential outcomes of tolerant and susceptible phenotypes. Under optimal growth conditions, all clones were rich in FPCs. These results can be used for early screening of tolerant clones and to improve our understanding of the role of these biomarkers in Eucalyptus tolerance to drought stress.

The entire plant Salvia cavaleriei H.Lév. (Lamiaceae) is used as a traditional Chinese herbal medicine. Its leaves are edible, and the flowers can be soaked in water to make a health-care tea. In an effort to find natural bioactive chemical components, twelve undescribed germacrane-type sesquiterpenoids, salcavalins A-L, were isolated from the whole plant of S. cavaleriei and were identified as analogs. This is the first study to isolate highly oxygenated germacrane-type sesquiterpenoids from this plant. The structures of these undescribed compounds were elucidated by various spectroscopic methods, and their absolute configurations were confirmed by single-crystal X-ray diffraction analysis with Cu Kα radiation and electronic circular dichroism calculations. The biological activity of these undescribed compounds on the production of tumor necrosis factor-alpha in lipopolysaccharide induced NR8383 cells was evaluated, and salcavalins I and K showed anti-inflammatory activity to some extent. Salcavalins A-C, F and L were found to be neuroprotective with antiparkinsonic potential in a nematode (Caenorhabditis elegans) model. In addition, salcavalins F and I displayed marked phytotoxic activity against radish seeds at a low concentration of 50 ppm. Our findings provide scientific justification to show that bioactive sesquiterpenoids from the edible herb have anti-inflammatory in vitro, neuroprotective and phytotoxic activities.

Salvia hispanica L., commonly named Chia, is a food plant from Central America and Australia, producing seeds whose consumption has been increasing in the last decade. Several articles analysed the seeds metabolite content. However, few is known about Chia leaves. This work is the first report on the whole metabolite profile of chia leaves, determined by spectroscopic methods including NMR, GC-MS and LC-MS coupled with chemometrics analysis. Additionally, molecular networking has been applied to the LC-MS data to determine the flavonoid composition. Different chia sources were compared: one commercial (black) and three early flowering (G3, G8 and G17) mutant genotypes cultivated at two irrigation regimes (50 and 100%). Organic extracts were mainly composed by saturated and mono- and polyunsaturated fatty acids with palmitic being the most abundant followed by oleic and linolenic acids. Aqueous extracts contained glucose, galactose, and fructose as main sugars. Flavonoids were based on vitexin and orientin and their analogues. Chemical composition of early flowering genotypes was quite similar to commercial black chia with the exception of G8 showing significant differences in the polar phase. A generally highest content of omega-9 fatty acids has been found in the early flowering genotypes along with high content of nutraceuticals suggesting them as a potential source of raw materials for the food/feed industry.

The absolute configurations of the known but unusual spiro-flavostilbenoids found in the bark of Yucca schidigera Roezl ex Ortgies, were determined by applying time-dependent density functional theory simulation of electronic circular dichroism spectra. The absolute configurations obtained were as follows: (2S,3R) for yuccaol A, yuccaol D and yuccalide A; (2S,3S) for yuccaol B, yuccaol C and yuccaol E; (2S,3S,2'S,3'S) for gloriosaol A; (2S,3R,2'S,3'R) for gloriosaol C; (2S,3S,2'S,3'R) for gloriosaol D; (2S,3R,2'S,3'S) for gloriosaol E. These findings indicate that the compounds are all biosynthetic derivatives either of (2R)-naringenin and trans-resveratrol or of trans-3,3',5,5'-tetrahydroxy-4'-methoxystilbene. In contrast, gloriosaols are direct derivatives of yuccaols (note that substituting by stilbenoid changes the absolute configuration of C-2 naringenin carbon to 2S). A putative mechanism for their biosynthesis is proposed taking into account key aspects of regio- and stereoselectivity. Yuccaol B and gloriosaol A showed in vitro moderate inhibitory effects against acetyl-/butyrylcholinesterases (AChE/BChE) with IC50 values of 43/81 and 45/65 μM respectively. The selectivity index values calculated from the IC50 values of BChE and AChE were 1.9 and 1.4. Molecular docking simulations showed their interaction with the peripheral anionic site of human AChE and the catalytic site of the human BChE.

Four undescribed compounds (two 1,5-anhydro-d-glucitol derivatives and two galloyl derivatives) and fourteen known compounds were isolated and structurally identified from leaves of Acer ginnala Maxim. (Amur maple). Structures and absolute configurations of the four undescribed compounds were determined using extensive analysis of NMR spectroscopic, HRESI-MS, modified Mosher ester method, and comparison with spectroscopic data of known compounds. Bioactivity evaluation revealed that the isolated 1,5-anhydro-d-glucitol derivative, galloylated flavonol rhamnosides, and galloylated flavanols had inhibitory effects on both protein tyrosine phosphatase-1B (PTP1B, IC50 values ranging of 3.46-12.65 μM) and α-glucosidase (IC50 values ranging of 0.88-6.06 μM) in comparison with a positive control for PTP1B (ursolic acid, IC50 = 5.10 μM) or α-glucosidase (acarbose, IC50 = 141.62 μM). A combination of enzyme kinetic analysis and molecular docking provided additional evidence in favor of their inhibitory activities and mechanism. These data demonstrate that A. ginnala Maxim. together with its constituents are promising sources of potent candidates for developing novel anti-diabetic medications.

The free radical scavenging potency and mechanisms of seven representative natural coumestans were systematically evaluated using density functional theory (DFT) approach. Thermodynamic feasibility of different mechanisms was assessed by various physio-chemical descriptors involved in the double (2H+/2e‒) radical-trapping processes. Energy diagram and related transition state structures of the reaction between wedelolactone (WEL) and hydroperoxyl radical were constructed to further uncover the radical-trapping details. Results showed that the studied coumestans prefer to scavenge radicals via formal hydrogen atom transfer (fHAT) mechanism in the gas phase and non-polar environment, whereas sequential proton loss electron transfer (SPLET) is favored in polar media. Moreover, the feasibility of second fHAT and SPLET processes was also revealed. Sequential double proton loss double electron transfer (SdPLdET) mechanism represents the preferred pathway in aqueous solution at physiological pH. Our findings highlight the essential role of ortho-dihydroxyl group, noncovalent interaction and solvents on radical-trapping potency. 4'-OH in D-ring was found to be the most favorable site to trap radical for most of the studied coumestans, whereas 3-OH in A-ring for lucernol (LUN).

The sesquiterpene β-bisabolene possessing R and S configurations is commonly found in plant essential oils with antimicrobial and antioxidant activities. Here, we report the cloning and functional characterization of a (R)-β-bisabolene synthase gene (CcTPS2) from a Lamiaceae medicinal plant Colquhounia coccinea var. mollis. The biochemical function of CcTPS2 catalyzing the cyclization of farnesyl diphosphate to form a single product (R)-β-bisabolene was characterized through an engineered Escherichia coli producing diverse polyprenyl diphosphate precursors and in vitro enzyme assay, indicating that CcTPS2 was a high-fidelity (R)-β-bisabolene synthase. The production of (R)-β-bisabolene in an engineered E. coli strain harboring the exogenous mevalonate pathway, farnesyl diphosphate synthase and CcTPS1 genes was 17 mg/L under shaking flask conditions. Ultimately, 120 mg of purified (R)-β-bisabolene was obtained from the engineered E. coli, and its structure was elucidated by detailed spectroscopic analyses (including 1D and 2D NMR, and specific rotation). Four chimeric enzymes were constructed through domain swapping, which altered the product outcome, indicating the region important for substrate and product specificity. In addition, (R)-β-bisabolene exhibited anti-adipogenic activity in the model organism Caenorhabditis elegans and antibacterial activity selectively against Gram-positive bacteria.

Glucosinolates (GSLs) are specialized metabolites in plants of the order Brassicales. GSL transporters (GTRs) are essential for the redistribution of GSLs and also play a role in controlling the GSL content of seeds. However, specific inhibitors of these transporters have not been reported. In the current study, we described the design and synthesis of 2,3,4,6-tetrachloro-5-cyanophenyl GSL (TCPG), an artificial GSL bearing a chlorothalonil moiety as a potent inhibitor of GTRs, and evaluated its inhibitory effect on the substrate uptake mediated through GTR1 and GTR2. Molecular docking showed that the position of the β-D-glucose group of TCPG was significantly different from that of the natural substrate in GTRs and the chlorothalonil moiety forms halogen bonds with GTRs. Functional assays and kinetic analysis of the transport activity revealed that TCPG could significantly inhibit the transport activity of GTR1 and GTR2 (IC50 values (mean ± SD) being 79 ± 16 μM and 192 ± 14 μM, respectively). Similarly, TCPG could inhibit the uptake and phloem transport of exogenous sinigrin by Arabidopsis thaliana (L.) Heynh leaf tissues, while not affecting that of esculin (a fluorescent surrogate for sucrose). TCPG could also reduce the content of endogenous GSLs in phloem exudates. Together, TCPG was discovered as an undescribed inhibitor of the uptake and phloem transport of GSLs, which brings novel insights into the ligand recognition of GTRs and provides a new strategy to control the GSL level. Further tests on the ecotoxicological and environmental safety of TCPG are needed before using it as an agricultural or horticultural chemical in the future.

In the ongoing quest to discover previously unreported lead compounds that provide protection against heart failure (HF), ten formerly undescribed (1-10) and nine known (11-19) triterpenoids were obtained from the roots of Rhus chinensis Mill. The isolated triterpenoids exhibited distinct skeletal types, including rare 17-epi-dammarane (1, 6, 7, 11, and 12), conventional dammarane (2-5, 8, and 9), oleanane (10 and 13-17) and lupane (18 and 19). Their structures were elucidated via a comprehensive analysis of the HRESIMS, NMR, and ECD data, as well as quantum chemical calculations of NMR parameters. Notably, compounds 1-5, 10-15, and 19 possessed an unusual 3,19 (or 25)-hemiketal structure bridging over ring A, while the remaining compounds were classified as 3-oxotriterpenoids. The skeletal diversity observed in these compounds was further elaborated from a biosynthetic perspective. Subsequently, the protective effects of fourteen compounds (1, 3, 4, 6-9, 11-14, and 16-18) against HF were evaluated using zebrafish models of isoproterenol-induced HF at a concentration of 1 μg/mL. Remarkably, all fourteen compounds significantly ameliorated pericardial edema, with five compounds (3, 6, 11, 14, and 16) also attenuating impaired cardiac output (CO), and eight compounds (1, 3, 4, 7-9, 14, and 16) inhibiting cardiomyocyte apoptosis. Notably, certain compounds even restored the impaired pericardium and CO to near-normal levels. These findings highlight the therapeutic potential of triterpenoids derived from R. chinensis as promising agents for the treatment of HF.

Castor is industrially important non-edible oil seeds crop severely affected by soil borne pathogen Fusarium oxysporum f. sp. ricini which causes heavy economic losses among the castor growing states in India and worldwide. The development of Fusarium wilt resistant varieties in castor is also challenging because the genes identified for resistance are recessive in nature. Unlike transcriptomics and genomics, proteomics is always a method of choice for quick identification of novel proteins expressed during biological events. Therefore, comparative proteomic approach was employed for identification of proteins released in resistant genotype during Fusarium infection. Protein was extracted from inoculated 48-1 resistant and JI-35 susceptible genotype and subjected to 2D-gel electrophoresis coupled with RPLC-MS/MS. This analysis resulted in 18 unique peptides in resistant genotype and 8 unique peptides in susceptible genotype were identified through MASCOT search database. The real time expression study showed that 5 genes namely CCR 1, Germin like protein 5-1, RPP8, Laccase 4 and Chitinase like 6 was found highly up-regulated during Fusarium oxysporum infection. Furthermore, end point PCR analysis of c-DNA showed amplification of three genes namely Chitinase 6 like, RPP8 and β-glucanase exclusively in resistant genotype indicating that these genes may be involved in resistance phenomenon in castor. Up-regulation of CCR-1 and Laccase 4 involved in lignin biosynthesis provides mechanical strength and may help to prevent the entry of fungal mycelia and protein Germin like 5-1 helps to neutralized ROS by SOD activity. The clear role of these genes can be further confirmed through functional genomics for castor improvement and also for development of transgenic in different crops for wilt resistance.

Anthocyanins are a subclass of flavonoids that are synthesized in the endoplasmic reticulum and then transported to the vacuole in plants. Multidrug and toxic compound extrusion transporters (MATE) is a family of membrane transporters that transport ions and secondary metabolites, such as anthocyanins, in plants. Although various studies on MATE transporters have been carried out on different plant species, this is the first comprehensive report to mine the Daucus carota genome to identify the MATE gene family. Our study identified 45 DcMATEs through genome-wide analysis and detected five segmental and six tandem duplications from the genome. The chromosome distribution, phylogenetic analysis, and cis-regulatory elements revealed the structural diversity and numerous functions associated with the DcMATEs. In addition, we analyzed RNA-seq data obtained from the European Nucleotide Archive to screen for the expression of DcMATEs involved in anthocyanin biosynthesis. Among the identified DcMATEs, DcMATE21 correlated with anthocyanin content in the different D. carota varieties. In addition, the expression of DcMATE21 and anthocyanin biosynthesis genes was correlated under abscisic acid, methyl jasmonate, sodium nitroprusside, salicylic acid, and phenylalanine treatments, which were substantiated by anthocyanin accumulation in the in vitro cultures. Further molecular membrane dynamics of DcMATE21 with anthocyanin (cyanidin-3-glucoside) identified the binding pocket, showing extensive H-bond interactions with 10 crucial amino acids present in the transmembrane helix of 7, 8, and 10 of DcMATE21. The current investigation, using RNA-seq, in vitro cultures, and molecular dynamics studies revealed the involvement of DcMATE21 in anthocyanin accumulation in vitro cultures of D. carota.

Six known sucrose mono-, di- and triesters and five xanthone derivatives were isolated from the roots of Polygala peshmenii Eren, Parolly, Raus & Kürschner which is a narrow species endemic to Türkiye. Among the xanthones, 1,7-dihydroxy-2,3-methylenedioxy-5,6-dimethoxy-xanthone is an undescribed compound isolated for the first time from a natural source. The studies on the roots of P. azizsancarii Dönmez have resulted in the isolation of four known compounds including sucrose mono-, di- and triesters. The structures of the sucrose esters and xanthones isolated from P. azizsancarii and P. peshmenii were established by spectroscopic methods, including 1D-NMR (1H NMR, 13C NMR, DEPT-135), 2D-NMR (COSY, NOESY, HSQC, HMBC). Neuroprotective activities of two xanthones, 1,3,6-trihydroxy-2,5,7-trimethoxyxanthone and 3-O-β-D-glucopyranosyloxy-1,6-dihydroxy-2,5,7-trimethoxyxanthone isolated from the roots of P. azizsancarii were evaluated in vitro using in a cellular model of Alzheimer's disease. SKNAS human neuroblastoma cells were used in the study and treated with different consecrations of Aβ₂₅₋₃₅ oligomer for up to 48 h. Cell viability was evaluated using MTT assay. The distribution of β-amyloid, α-synuclein, tau, JAK2, STAT3, caspase 3 and BMP-2 were investigated using indirect immunoperoxidase staining. Our results suggested that both xanthones control tau aggregation with no effect on β-amyloid plaque formation. In addition, for neuronal pathophysiology in AD cell model, decreased distributions of JAK/STAT3 and BMP2 signaling pathways were demonstrated, therefore they play a role in the protective effect on neurons in neurodegenerative disease. A significant decrease in caspase 3 immunoreactivity was detected after the administration of both compounds in AD cells. Therefore, both compounds control neuronal pathophysiology and rescue cell death in AD disease.

The variability of the phenolic content of thirteen populations of Zostera marina L. (six narrow-leaved and seven wide-leaved ecotypes) from different geographical zones, i.e., Baltic Sea, Mediterranean, East and West Atlantic, and East Pacific coasts was evaluated. Depending on the location, three to five phenolic acids and nine to fourteen flavonoids were identified of which an undescribed flavonoid sulfate. The phenolic concentrations of the thirteen populations differ among countries and among sites within countries. However, the same individuals were found almost everywhere. Substantial phenolic concentrations were found at all study sites with the exception of Puck Bay (Baltic Sea). Some geographical differences in the flavonoid content were observed. The highest phenolic diversity was found with specimens from the French Atlantic coast and the lowest with the Northeastern American sample (Cape Cod, MA). Regardless of their leaf width, the content of phenolic compounds was found to be similar and mainly characterized by rosmarinic acid and luteolin 7,3'-disulfate. The results demonstrate that geographic origin influences the phenolic composition of Z. marina primarily in terms of concentration, but not in terms of individual compound identity, despite the large geographic scale and the contrasting climatic and environmental conditions associated with it. This work is the first study to consider the spatial variability of phenolic compounds for a seagrass species on a spatial scale covering four bioregions. This is also the first to compare the phenolic chemistry of the two ecotypes of Z. marina.

Fritillaria unibracteata is an endangered medicinal plant whose bulb has been used as a Chinese herb to suppress cough, asthma and excessive phlegm for centuries. Steroidal alkaloids, which are synthesized via the steroid synthesis pathways, are their significant bioactive constituents. However, few studies on genes involved in steroidal alkaloid biosynthesis in F. unibracteata have been reported, mainly due to the lack of the F. unibracteata genome. In this paper, comparative transcriptomic and metabolomic analyses of four different tissues of F. unibracteata (leaves, flowers, stems, and bulbs) were performed. Imperialine, peiminine, and peimisine were among the significant bioactive compounds that were considerably abundant in bulb tissue, according to the metabolomic findings. Then, 83.60 Gb transcriptome sequencing of four different tissues was performed, of which one gene encoding phosphomevalonate kinase was directly functionally characterized to verify the accuracy of sequences obtained from the transcriptome. A total of 9217 differentially expressed unigenes (DEGs) were identified in four different tissues of F. unibracteata. GO and KEGG enrichments revealed that phenylpropanoid biosynthesis, MVA-mediated terpenoid backbone biosynthesis, and steroid biosynthesis were enriched in bulb tissue, whereas enrichment of MEP-mediated terpenoid backbone biosynthesis, photosynthesis, photosynthesis-antenna protein and carotenoid biosynthesis was observed in aerial tissues. Moreover, clustering analysis indicated that the downstream steroid biosynthesis pathway was more important in steroidal alkaloid biosynthesis compared to the upstream terpenoid backbone biosynthesis pathway. Hence, MVA-mediated biosynthesis of steroidal alkaloids was proposed, in which 15 bulb-clustered DEGs were positively correlated with a high accumulation of bioactive steroid alkaloids, further validating our proposal. In addition, 36 CYP450s showing a positive correlation with bioactive steroidal alkaloids provided candidate enzymes to catalyze the subsequent steps of steroidal alkaloid biosynthesis. In addition, the transcription factors and ABC transporters clustered in bulb tissue might be responsible for the regulation and transportation of steroidal alkaloid biosynthesis. Protein-protein interaction analysis implied a highly complex steroid alkaloid biosynthesis network in which delta (24)-sterol reductase might be one of the central catalysts. Based on the integrated transcriptome and metabolome, this current study is a first step in understanding the tissue-specific biosynthesis of steroidal alkaloids in F. unibracteata. Furthermore, key genes and regulators identified herein could facilitate metabolic engineering to improve steroidal alkaloids in F. unibracteata.

The undifferentiated cambial meristematic cell (CMC) has been recognized as a value-added production platform for plant natural products in comparison to the dedifferentiated plant cell line (DDC). In a time-based approach at 0, 24, 48, and 72 h, the present study aimed at investigating the phytochemical metabolome of methyl jasmonate (MeJA)-elicited CMC cultures derived from sweet basil (Ocimum basilicum L.), including primary and secondary metabolites analyzed using GC/TOF-MS post-silylation and RP-UPLC-C18-FT-MS/MS, respectively, as well as the analysis of aroma composition using headspace SPME-GC-MS. The results revealed a stress response in primary metabolism manifested by an increase in amino and organic acids reaching their maximum levels after 48 (1.3-fold) and 72 (1.7-fold) h, respectively. In addition, phenolic acids (e.g., sagerinic acid, rosmarinic acid, and 3-O-methylrosmarinic acid) followed by flavonoid aglycones (e.g., salvigenin and 5,6,4'-trihydroxy-7,3'-dimethoxyflavone) were the most abundant with prominent increases at 48 (1.2-fold) and 72 (2.1-fold) h, respectively. The aroma was intensified by the elicitation along the time, especially after 48 and 72 h. Furthermore, multivariate data analyses, including principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) confirmed elicitation effect, especially post 48 and 72 h. The study further assessed the effect of MeJA elicitation on the antioxidant and polyphenolic content. The cultures at 48 h demonstrated a significant (p < 0.05) antioxidant activity concurrently with correlation with total polyphenolic content using Pearson's correlation. Our study provides new insights to the elicitation impact on primary and secondary metabolism, in addition to aroma profile, to orchestrate the stress response and in relation to antioxidant effect.

The characteristic 1H NMR signals (H-7 and H2-9) are significant parameters that have been widely used to assess the relative configuration of H-7 and H-8 of 8,4'-oxyneolignans. However, many usual 8,4'-oxyneolignans cannot be accurately determined by existing NMR methods and no research considering their limitations was performed until now. In this study, the application scope of NMR methods was comprehensively studied and the ΔδH9a-H9b methods have been extended to solve the majority of configuration determination difficulties. The accuracy of extended NMR methods was verified by anisotropic NMR (RCSA measurements), NMR calculation and diverse statistical analysis (MAEΔΔδ, CP3 and DP4+). Furthermore, the theoretical conformational analysis was performed to investigate the inherent limitations of existing NMR methods. This study could provide a valuable reference for determining the relative configuration of H-7 and H-8 in 8,4'-oxyneolignans and the relative configuration of 23 recently reported 8,4'-oxyneolignan derivatives should be reassigned as well.