Secondary metabolites from the endophytic fungus Biscogniauxia formosana and their antimycobacterial activity

Two new azaphilone derivatives, namely, biscogniazaphilones A (1) and B (2), along with ten known compounds (3–12), were isolated from the n-BuOH-soluble fraction of the 95% EtOH extract of long-grain rice fermented with the endophytic fungus Biscogniauxia formosana BCRC 33718, derived from the bark of medicinal plant Cinnamomum species. Their structures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR as well as HRESIMS, ESIMS, UV, and IR, and comparison with literature data. In addition, the isolated compounds (1–12) were evaluated for their antimycobacterial activity. Two new constituents, biscogniazaphilones A (1) and B (2), exhibited the strongest antimycobacterial activities against Mycobacterium tuberculosis strain H₃₇Rv, with MIC values of 5.12 and 2.52 μg/mL, respectively.     

Cytotoxic azaphilone alkaloids from Chaetomium globosum TY1

Three novel azaphilone alkaloids, namely chaetomugilides A–C (1–3), together with three related compounds (4–6) were isolated from the methanol extract of Chaetomium globosum TY1, an endophytic fungus isolated from Ginkgo biloba. Their structures were elucidated on the basis of extensive 1D and 2D NMR as well as HRESI-MS spectroscopic data analysis. The isolated compounds exhibited highly cytotoxic activities against human cancer cell line HePG2 with the IC₅₀ values range from 1.7 to 53.4 μM.     

Cytotoxic polyketides from endophytic fungus Phoma bellidis harbored in Ttricyrtis maculate

Four new polyketides, namely bellidisins A-D (1-4), were isolated from rice fermentation extract of endophytic fungus Phoma bellidis, along with three known compounds pinolidoxin (5), 5,6-epoxypinolidoxin (6), and 2-epi-herbarumin II (7). Their structures and absolute configurations were determined by 1D and 2D NMR, HRESIMS and ECD calculation. Their cytotoxicity was evaluated against human cancer cell lines HL-60, A549, SMMC-7721, MCF-7, and SW480. Compound 4 showed significant cytotoxicity on these five cell lines with IC₅₀ value ranged from 3.40 to 15.25 μM, which is stronger than cisplatin (4.86–27.70 μM).     

Bioactivity-guided isolation of chemical constituents against H2O2-induced neurotoxicity on PC12 from Cimicifuga dahurica (Turcz.) Maxim.

Three new compounds (1, 6, 9), with six known compounds (2–5, 7–8) were obtained from water-soluble extract of Cimicifuga dahurica (Turcz.) Maxim. by bioactivity-guided isolation. Their structures were elucidated by chemical and spectral analysis, including 1D, 2D NMR data and HRESIMS. H₂O₂-induced neurotoxicity on PC12 cells model were conducted to evaluate the neuro-protective capability of these compounds. The piscidic acid derivatives compounds 4–7 showed marked neuro-protective effect at certain concentration.     

Bioactive triterpenoids from twigs of Betula schmidtii

Investigation of the MeOH extract of Betula schmidtii twigs resulted in the isolation and identification of three new triterpenoids (1–3), along with ten known ones (4–13). The structures of new compounds (1–3) were elucidated by spectroscopic methods, including 1D, 2D NMR (¹H and ¹³C NMR, COSY, HSQC, HMBC, and NOESY), HR-MS, and chemical methods. All the isolated compounds were evaluated for their cytotoxicity against A549, SK-OV-3, SK-MEL-2, and HCT-15 cell lines. Compound 11 exhibited potent cytotoxic activities against four cell lines, and compounds 5 and 13 significantly induced nerve growth factor secretion in a C6 rat glioma cell line. Their anti-inflammatory effects were also assessed by measuring nitric oxide production in lipopolysaccharide–activated BV-2 cells. Compounds 7 and 12 displayed potent inhibition of nitric oxide production, without significant cell toxicity.     

Terpenoids and other constituents from Euphorbia bupleuroides

The phytochemical investigation of the roots of Euphorbia bupleuroides Desf. (Euphorbiaceae) yielded three new compounds named 4,20-dideoxy(4α)phorbol-12-benzoate-13-isobutyrate (1), 25-hydroperoxycycloart-3β-ol (2), and 3β,7β-dihydroxy-4α,14α-dimethyl-8β,9β-epoxy-5α-ergosta-24(28)-ene (3), together with 17 known compounds 4–20. Their structures were established from analysis of 1D (¹H, ¹³C and DEPT) and 2D NMR (COSY, HSQC, HMBC and NOESY) data, and of mass spectrometry (HRESIMS), and by comparison with literature data.     

Three new compounds isolated from the bulbs of Fritillaria pallidiflora Schrenk and their anti-inflammatory activity

Three new compounds, 17β-cevanin-6-oxo-5α,20β-diol yibeinine (1), 2-(tetrahydro-5-(2-hydroxyphenyl)-2H-pyran-3-yl) phenol (2), 1,3-O-diferuloyl-2-methoxypropane diol (3), as well as four known compounds (4–7), have been isolated from the ethanol extract of dried bulbs of Fritillaria pallidiflora Schrenk. All structures were determined based on their spectroscopic data (1D and 2D NMR (including ¹H NMR, ¹³C NMR, ¹H-¹H COSY, HMBC, HSQC, HSQC-TOCSY, and NOESY experiments), and MS). Biological evaluation showed that compounds 1–4 inhibited the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 cells with IC₅₀ values of 18.0, 38.7, 29.5, and 47.1 μM, respectively. These results indicated that compound 1 has potential anti-inflammatory activity.     

Isopimarane-type diterpenoids from Callicarpa macrophylla vahl

Three new isopimarane-type diterpenoids, named callicapene M1 (1), callicapene M2 (2), and callicapene M3 (3), together with four known isopimarane-type diterpenoids (4, 5, 6, 7), were isolated from the Callicarpa macrophylla Vahl. Their structures were elucidated by spectroscopic techniques (IR, UV, MS, 1D, 2D NMR). The isolated compounds 6 and 7 exhibited potent inhibitory activity with inhibition rates of 40.23–46.78% on NO production in LPS-activated RAW 264.7 macrophage cells by using MTT assays.     

Cytotoxic oligophenols from the rhizome of Wikstroemia indica

A new tricoumarin glycoside, triumbelletin-7-O-β-d-glucoside (1) and a new biflavonoid, wikstroflavone A (2), together with two known compounds, wikstaiwanone A (3) and wikstaiwanone B (4), were isolated from the rhizome of Wikstroemia indica. The structures of new compounds were elucidated by extensive spectroscopic techniques (UV, IR, HRESIMS, 1D, 2D NMR and CD), in combination with quantum chemical calculations of ¹³C NMR and ECD spectra. All isolates were tested for their antineoplastic activities against cancer-derived cell lines HCT116, SW480, U87 and T98G. Compounds 2–4 exhibited moderate cytotoxic activities to the four cell lines. The flow cytometry assay and western blot analysis revealed that the cytotoxic effects were possibly attributed to the induced apoptotic cell death.     

Chemical constituents from the seeds of Raphanus sativus L. and their chemotaxonomic significance

The phytochemical investigations on the seeds of Raphanus sativus L. led to the isolation and identification of 15 compounds, including eleven sinapoyl derivatives (1–11), two terpenes (12–13), and two phenolic acids (14–15). All chemical structures were elucidated via ¹H NMR and ¹³C NMR spectroscopic methods, and further supported by comparison with literature data. Compound 11 was isolated from the genus Raphanus for the first time. Notably, Compounds 7, 9, and 12–14 were reported in the Brassicaceae family for the first time. The chemotaxonomic significance of these compounds is discussed.     

Five new iridoïd dimers from the fruits of Canthium subcordatum DC (syn. Psydrax subcordata DC)

Five new iridoid dimers, canthiumosides 1–5 (1–4 and 5a), together with nine known compounds, shanzhigenin methyl ester (6), 1-epishanzhigenin methyl ester (6′), linearin (7), 1-epilinearin (7′), mussaenoside (8), shanzhiside methyl ester (9), 3′,4′,7-trihydroxyflavone (10), betulinic acid (11), and oleanolic acid (12) were isolated from the fruits of Canthium subcordatum DC (Syn. Psydrax subcordata (DC) Bridson). The structures of these compounds were established by interpretation of their spectral data, mainly HR-TOFESIMS, 1D NMR (¹H, ¹³C and DEPT) and 2D NMR (¹H–¹H COSY, HSQC, HMBC, and NOESY), and by comparison with the literature.     

Antimicrobial phenolic metabolites from the aerial parts of Orthosiphon aristatus

Two new compounds oraristatin A (1) and oraristatinoside A (2), one new natural compound (2 S)-methyl-6,7-dihydroxytropate (3), and 11 known phenolic metabolites were isolated from the aerial parts of Orthosiphon aristatus. Their chemical structures were identified by 1D- and ²D NMR and HRESIMS spectroscopic analyses. The absolute configurations of 1 and 3 were determined by TD-DFT ECD spectroscopic analyses. Of the isolates, compound 2 weakly inhibited both Gram-positive and -negative bacteria (MIC = 150–300 μM), while 6 and 7 suppressed the growth of three Gram-positive bacteria and a yeast (MIC = 75–150 μM). This is the first report of the isolation of 6 − 9, 12, and 14 from the genus Orthosiphon and the antimicrobial effects of compounds 3, 7, 9, 12, and 14.     

Phenolic compounds with radical scavenging and cyclooxygenase-2 (COX-2) inhibitory activities from Dioscorea opposita

Phytochemical studies of the chloroform soluble fraction of Dioscorea opposita resulted in the isolation of four new compounds, 3,5-dihydroxy-4-methoxybibenzyl (1), 3,3′,5-trihydroxy-2′-methoxybibenzyl (2), 10,11-dihydro-dibenz[b,f]oxepin-2,4-diol (3), and 10,11-dihydro-4-methoxy-dibenz[b,f]oxepin-2-ol (4), together with an additional fifteen known compounds. The structures of 1–4 were elucidated by spectroscopic methods including 2D NMR. All of the nineteen isolated compounds were tested in the DPPH, superoxide anion radical scavenging assays and cyclooxygenases (COXs) inhibition assay. Of those, compounds 7, 9, 11, 12, 13, 15 and 18 exhibited radical scavenging activities and compounds 2, 3, 8, 13, 15 and 16 showed selective inhibitory activities against COX-2.     

Alkenylresorcinols and cytotoxic activity of the constituents isolated from Labisia pumila

Phytochemical investigation on the leaves of Labisia pumila (Myrsinaceae), an important medicinal herb in Malaysia, has led to the isolation of 1-O-methyl-6-acetoxy-5-(pentadec-10Z-enyl)resorcinol (1), labisiaquinone A (2) and labisiaquinone B (3). Along with these, 16 known compounds including 1-O-methyl-6-acetoxy-5-pentadecylresorcinol (4), 5-(pentadec-10Z-enyl)resorcinol (5), 5-(pentadecyl)resorcinol (6), (−)-loliolide (7), stigmasterol (8), 4-hydroxyphenylethylamine (9), 3,4,5-trihydroxybenzoic acid (10), 3,4-dihydroxybenzoic acid (11), (+)-catechin (12), (−)-epicatechin (13), kaempferol-3-O-α-rhamnopyranosyl-7-O-β-glycopyranoside (14), kaempferol-4′-O-β-glycopyranoside (15), quercetin-3-O-α-rhamnopyranoside (16), kaempferol-3-O-α-rhamnopyranoside (17), (9Z,12Z)-octadeca-9,12-dienoic acid (18) and stigmasterol-3-O-β-glycopyranoside (19) were also isolated. The structures of these compounds were established on the basis of 1D and 2D NMR spectroscopy techniques (¹H, ¹³C, COSY, HSQC, NOESY and HMBC experiments), mass spectrometry and chemical derivatization. Among the constituents tested 1 and 4 exhibited strongest cytotoxic activity against the PC3, HCT116 and MCF-7 cell lines (IC₅₀ values ⩽10 μM), and they showed selectivity towards the first two-cell lines relative to the last one.     

Lactones from the pericarps of Litsea japonica and their anti-inflammatory activities

Five new lactones, litsenolide F₁ (1), lisealactone H₁ (10), lisealactone H₂ (11), akolactone D (13), and akolactone E (14), along with thirteen known compounds were isolated from the pericarps of Litsea japonica (Thunb.) Jussieu. Their chemical structures were elucidated by extensive spectroscopic analyses, including 1D and 2D NMR, HRMS, and chemical methods. The isolated compounds were evaluated for their inhibitory effects on NO production in lipopolysaccharide (LPS)-stimulated RAW264.7 cells. Among them, 2-alkylidene-3-hydroxy-4-methylbutanolide derivatives (compounds 1–9) exhibited the most potent activity, with IC₅₀ values in the range of 2.9–12.8?μM. In additon, compounds 1, 3, 4, and 6 showed inhibition of iNOS and COX-2 expression in concentration-dependent manner. Compound 3 suppresses mRNA expression of iNOS, COX-2, IL-6, and TNF-α in LPS-stimulated RAW264.7 cells. Based on these evidence, the isolated lactones from L. japonica could be promissing candidates for the development of new anti-inflammatory agents.     

Anti-inflammatory iridoid glycosides from fruits of Cornus officinalis

Three undescribed iridoid glycosides, cyc(7β-O-6′)-morroniside (1), 6′-methyl succinate-7β-O-methylmorroniside (2), and 7β-O-methyl phenyllactate morroniside (3) were isolated from 50% ethanol extract of Cornus officinalis fruits. The structures of the isolated compounds were determined by HRESIMS, ¹D NMR, ²D NMR, UV and IR spectroscopic methods. Compounds 1-3 exhibited moderate anti-inflammatory activities in vivo in a CuSO₄-induced zebrafish inflammation model (when evaluated at 50 μM).     

Two new components from the rhizome of Anemarrhena asphodeloides Bge. and their antiplatelet aggregative activity

Two new components, anemarrhena A (1) and anemarrhena B (2), together with five known ones (3–7), were isolated from the rhizome of Anemarrhena asphodeloides Bge. Their structures were established by detailed spectral studies, including 1D-NMR (¹H NMR, ¹³C NMR and DEPT), 2D-NMR (HSQC, HMBC and NOESY), HR-ESI-MS and by the comparison with literature data. The absolute configuration of 2 was further determined by CD analysis. The isolated compounds were evaluated for their antiplatelet aggregative activity. Compounds 1, 2, 3, 5, 6 and 7 exhibited moderate activity of antiplatelet aggregation in vitro, compound 4 showed potential antiplatelet aggregation activity.     

Lignan derivatives from Selaginella tamariscina and their nitric oxide inhibitory effects in LPS-stimulated RAW 264.7 cells

The chemical characterization of Selaginella tamariscina leaves resulted in the isolation of five lignanoside derivatives (1–4 and 6) and one neolignan (5). These compounds include three new lignanosides, tamariscinosides D–F (1–3), and one liriodendrin (4) that were isolated for the first time from this plant, together with two known compounds, (2R,3S)-dihydro-2-(3,5-dimethoxy-4-hydroxyphenyl)-7-methoxy-5-acetyl-benzofuran (5) and moellenoside B (6). The chemical structures of these isolated compounds were determined using 1D and 2D NMR, MS, and CD spectroscopic data, and the results were compared to data previously reported in the literatures. These compounds were also evaluated in terms of their inhibition of NO production in lipopolysaccharide (LPS)-stimulated activity in the macrophage cell line RAW 264.7. Among them, compounds 1, 2, 5, and 6 exhibited a significant inhibition with IC₅₀ values ranging from 32.3 to 55.8 μM.     

Phytochemical investigation of Eremostachys moluccelloides Bunge (Lamiaceae)

Phytochemical investigation of the aerial parts of Eremostachys moluccelloides Bunge led to the identification of a new diterpene, 2β,14-dihydroxy −11-formyl- 12-carboxy-13-des-isopropyl-13-hydroxymethyl-abieta-8,11,13- triene- 16(17)- lactone (1), along with the known compounds 12, 18-dicarboxy-14-hydroxy-13-des -isopropyl-13-hydroxymethyl- abieta-8,11,13-triene-16(17)-lactone (2), 5-hydroxy-3′,4′,7-trimethoxyflavone (3), 5-hydroxy-4’,7-dimethoxyflavone (4), luteolin-7-O-β-glucoside (5), verbascoside (6), luteolin 7-O-(6″-O-β-D-apiofuranosyl) -β-D-glucopyranoside (7), chlorogenic acid (8), echinacoside (9), apigenin-7-O-β-D-glucoside (10), p-coumaric acid (11), vanillic acid (12), apigenin-7-O-(6″-E-p-coumaroyl)-β-D-glucopyranoside (13), apigenin-7-O-(3″,6″-E-p-dicoumaroyl)-β-glucoside (14), lamalbide (15), 6β-hydroxy-7-epi-loganin (16), phloyoside II (17) The structures were elucidated on the basis of 1D and 2D NMR spectroscopy, UV, MS and by comparison with compounds previously reported in the literature. Compounds 1–4, 8, 9, 11, 12, 14 have not been reported previously from any species within the genus Eremostachys. Compounds 1–14, 17 were obtained from this species for the first time. The chemotaxonomic significance of the isolated compounds is discussed.     

Tricyclic diterpenes from the resin of Daemonorops draco and their activities on oxidative stress-induced mesenchymal stromal cells

A bioassay-guided chemical investigation of the resin exudates from Daemonorops draco (dragon’s blood, Palmaceae) has resulted in the isolation of two new trinorditerpenes, 7β-13-dihydroxypodocarpa-8,11,13-trien-15-oic acid (1) and 7α-13-dihydroxypodocarpa-8,11,13-trien-15-oic acid (2), along with ten previously described abietane diterpenes, 7β-15-dihydroxydehydroabietic acid (3), 7α-15-dihydroxydehydroabietic acid (4), 15-hydroxydehydroabietic acid (5), 7-oxodehydroabietic acid (6), dehydroabietic acid (7), 15-hydroxyabietic acid (8), 12α-hydroxyabietic acid (9), abietic acid (10), 7,13,15-abietatrien-18-oic acid (11), and cephasinene B (12). The structures of 1 and 2 were elucidated using spectroscopic techniques, including HR-ESIMS and 1D/2D NMR. The absolute configurations were determined by comparing the experimental electronic circular dichroism (ECD) spectra with the calculated ECD data based on time-dependent density functional theory. The bioactivity of the extracts, fractions, and isolated compounds was assessed in oxidative stress-induced mesenchymal stromal cells (MSCs). The crude extract and the hexanes, ethyl acetate, and aqueous fractions exhibited high potency against oxidative stress-induced apoptosis of MSCs. Among the isolated compounds, compounds 1 (3 μM) and 10 (100 μM) demonstrated good recovery of MSCs against oxidative stress.