Chemical constituents from the fruiting bodies of Amauroderma subresinosum

The chemical investigation on the fruiting bodies of Amauroderma subresinosum led to the isolation of 10 compounds including 2 new ones named amaurosubresin (1) and erythro(23,24)-5α,6α-epoxyergosta-8-ene-7-one-3β,23-diol (2). Their structures were elucidated on the basis of 1D and 2D NMR spectroscopy as well as MS. The bioassay of inhibitory activity against acetylcholinesterase (AChE) of two new isolates exhibited definite inhibitory activity.     

Chemical study of the fungus Psilocybe merdaria

Chemical investigation on the cultures of the fungus Psilocybe merdaria resulted in the first isolation of 10 compounds including two new ones 11,14-dihydroxylneoechinulin E (1) and (S)-4-(4-methylpent-3-en-1-yl)-butyrolactone (2). Their structures were elucidated from the analysis of 1D and 2D NMR and MS data. Among them, compound 7 showed inhibitory activity against AChE with 20% percentage at a concentration of 50 μg/ml.     

Chemical study of the strain Cordyceps spp. from cell fusion between Cordyceps militaris and Cordyceps cicadae

Chemical investigation on the cultures of the fungus Cordyceps spp., a strain from cell fusion between Cordyceps militaris and Cordyceps cicadae, resulted in the isolation of 13 compounds including 2 new ones named 2-(5-(3-oxobutyl) furan-2-yl) acetic acid (1) and cordycepone (2). Their structures were elucidated from the analysis of 1D/2D NMR and CD data. Among them, compounds 1, 7–9, at a concentration of 50 μg/ml, showed weak inhibitory activity against AChE. Moreover, compounds 6, 9, and 11 showed moderate inhibitory activity against the nematode Panagrellus redivivus with mortality ratio of 79.0, 71.7, and 72.3% at 2.5 mg/ml, respectively.     

2H-Pyranone and isocoumarin derivatives isolated from the plant pathogenic fungus Leptosphaena maculans

Abstract

Two new 2H-pyranones and two new isocoumarin derivatives, maculanslines A-D (1–4), together with seven known compounds (5–11), were isolated from the plant pathogenic fungus Leptosphaena maculans. Their planar structures and absolute configuration were elucidated by comprehensive spectroscopic techniques including high-resolution electrospray ionization mass spectrum, 1D and 2D nuclear magnetic resonance, as well as electronic circular dichroism. All 11 compounds were tested for their inhibitory activity against α-glucosidase. Compound 1 showed moderate inhibitory activity against α-glucosidase with IC₅₀ of 74.35 μM.     

Cholinesterase inhibitors from <Emphasis Type="Italic">Cleistocalyx operculatus</Emphasis> buds

Five flavonoids, myricetin-3′-methylether 3-O-β-d-galactopyranoside (1), myricetin-3′,5′-dimethylether 3-O-β-d-galactopyranoside (2), quercetin (3), kaempferol (4), and tamarixetin (5) were isolated from the buds of Cleistocalyx operculatus (Myrtaceae). The chemical structures of these compounds were determined on the basis of spectroscopic analyses, including 2D NMR. Their anti-Alzheimer effects were evaluated via acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activity assays. All five compounds 1–5 showed potential inhibitory activities against AChE with IC₅₀ values of 19.9, 37.8, 25.9, 30.4 and 22.3 μM, respectively, while compounds 1, 3, 4 and 5 also possessed BChE inhibitory activity with IC₅₀ values of 152.5, 177.8, 62.5, and 160.6 μM, respectively.     

A new highly oxygenated pregnane and two new 5-hydroxymethylfurfural derivatives from the water decoction of Poria cocos

Abstract

A new highly oxygenated pregnane steroid, pregn-7-ene-2β,3α,15α,20-tetrol (1) and two new 5-hydroxymethylfurfural derivatives, (5-formylfuran-2-yl)methyl 2-hydroxypropanoate (2) and (5-formylfuran-2-yl)methyl 2-(4-hydroxyphenyl)acetate (3), together with four known compounds, were isolated from the water decoction of Poria cocos. Their structures were established on the basis of extensive spectroscopic analysis. Compound 1 showed moderate inhibitory activity and a known compound (3S,6S)-3-[(1R)-1-hydroxyethyl]-6-(phenylmethyl)-2,5-piperazinedione (5) showed weak inhibitory activity against α-glucosidase, respectively.     

Depsitinuside: a new depside galactoside from an endophytic fungus isolated from Viburnum tinus

Chromatographic purification of the extract of an endophytic fungal culture yielded depsitinuside (1), a new phenolic ester together with ergosterol (2) and (22E,24S)-24-methyl-5-α-cholesta-7,22-diene-3β,5,6β-triol (3). The structure of 1 was elucidated based on 1D, 2D NMR spectroscopy and high-resolution mass spectrometry, whereas the known compounds (2 and 3) were identified by ¹H NMR, mass spectrometry, and in comparison with the literature values. Compound 1 was evaluated for its enzyme inhibitory potential against acetylcholinesterase, butyrylcholinesterase and lipoxygenase, and was found inactive (10%–40% inhibition at a concentration of 2 mg/ml).     

Anti-tumour clerodane-type diterpenes from Mitrephora thorelii

Bioassay-guided fractionation of the crude extract of Mitrephora thorelii (Annonaceae) led to the isolation of two clerodane-type diterpenes. Their structures were characterised on the basis of spectroscopic methods as 6α,16,18-trihydroxycleroda-3(4),13(14)-dien-15,16-olide (1) and 16-hydroxycleroda-3(4),13(14)-dien-15,16-olide (2). Compound 1 is a new compound. Compounds 1 and 2 exhibited inhibitory activity against the proliferation of human hepatoma BEL-7402 cells in vitro. Compound 2 also showed an in vivo anti-tumour effect against the growth of hepatoma H22 in mice.     

Two new diterpenes from the seeds of Caesalpinia minax Hance

Molecules with diterpene skeletons often possess valuable medicinal properties. Two new diterpenes 1α,6α,7β-triacetoxy-5α-hydroxy-14β-ethyl-O-vouacapane (1) and 2α-acetoxy-14,15-cyclopimara-7β,16-diol (2) were isolated from the seeds of Caesalpinia minax Hance. Their structures were established on the basis of extensive spectroscopic analyses, including HR-ESI-MS, UV, IR, 1D, and 2D NMR (HSQC, HMBC, NOESY) methods. The stereochemical structure of 1 was confirmed via the circular dichroism spectrum and calculated ECD experiment. The inhibitory activity of nitric oxide production of RAW264.7 macrophages stimulated by lipopolysaccharide of compounds 1 and 2 was evaluated, and compound 1 was found to show significant inhibitory effect.     

Isolation and structure elucidation of halymeniaol,a new antimalarial sterol derivative from the red alga Halymenia floresii

A new mono-hydroxy acetylated sterol derivative: 12β-hydroxy-3β, 15α, 16β-triacetoxy-cholest-5-en-7-one (halymeniaol) (1), and cholesterol (2) were isolated from the marine red alga Halymenia floresii. The structure of the compound 1 (halymeniaol) was established from its spectral data, derived from HRMS/MS and 2D NMR. Compound 1 exhibited growth inhibitory activity against chloroquine-resistant Plasmodium falciparum 3D7 strain with an IC₅₀ of 3.0 μM.     

Selective dual cholinesterase inhibitors from Aconitum laeve

New lycoctonine-type dual cholinesterase inhibitor, swatinine-C (1), along with three known norditerpenoid alkaloids, hohenackerine (2), aconorine (5) and lappaconitine (6) and two synthetically known but phytochemically new benzene derivatives, methyl 2-acetamidobenzoate (3) and methyl 4-[2-(methoxycarbonyl)anilino]-4-oxobutanoate (4), was isolated from the roots of A. laeve. Structures of new and known compounds (1–6) were established on the basis of latest spectroscopic techniques and by close comparison with the data available in literature. In vitro, compounds (1–6) were tested against AChE and BChE inhibitory activities. Compounds 1 and 2 showed competitive inhibition against AChE (IC_50?=?3.7 μM, 4.53 μM) and BChE (IC_50?=?12.23 μM, 9.94 μM), respectively. Compounds 5 and 6 showed promising noncompetitive type of inhibitory profile against AChE (IC_50?=?2.51 and 6.13 μM) only. Compounds 3 and 4 showed weak inhibitory profile against both AChE and BChE.     

Two new phragmalin-type limonoids from Chukrasia tabularis and their α-glucosidase inhibitory activity

Phytochemical investigation on the stems of C. tabularis (Meliaceae) led to the isolation of two new phragmalin-type limonoids, named tabularisins S and T (1–2), along with five known ones (3–7). The structures of the new limonoids were established by spectroscopic methods including UV, IR, HRESIMS, and 1D and 2D NMR. All the compounds were evaluated for α-glucosidase inhibitory activity in vitro. Compounds 2 and 3 exhibited significant inhibitory activity against α-glucosidase with IC₅₀ values of 0.15 and 0.03 mM, respectively (acarbose as positive control, IC₅₀ 0.95 mM).     

Terpenoids and bisbibenzyls from Chinese liverworts Conocephalum conicum and Dumortiera hirsuta

Four new monoterpene esters, 2α,5β-dihydroxybornane-2-cinnamate (1), 2α,5β-dihydroxybornane-5-acetyl-2-cinnamate (2), 2α,5β-dihydroxybornane-2-p-hydroxycinnamate (3) and 2α,5β-dihydroxy-bornane-2-cis-p-hydroxycinnamate (4), together with a known compound 3,4-dimethoxystyrene (5) were isolated from Chinese liverwort Conocephalum conicum and six known compounds, 5,7-dihydroxycalamenene (6), 7-hydroxycalamenene (7), lunularin (8), riccardin C (9), marchantin C (10) and riccardin D (11) were isolated from Dumortiera hirsuta. Their structures were elucidated by extensive spectral analysis and chemical correlations. Compounds 1 and 8 showed moderate cytotoxicity against human HepG2 cells with IC₅₀ 4.5 μg/ml and 7.4 μg/ml, respectively, while compound 8 also showed antimicrobacterial activity against Pseudomonas aeruginosa with minimum inhibitory concentration at 64 μg/ml.     

Triterpene saponins with α-glucosidase inhibition and cytotoxic activity from the leaves of Schefflera sessiliflora

From the leaves of Schefflera sessiliflora De P. V., two new triterpene saponins including one oleanane-type saponin, named scheffleraside C (1) and one lupane-type saponin scheffleraside D (2), together with six known triterpene saponins (3–8), were isolated by various chromatography methods. Among them, 3 was found for the first time from natural sources, while 6–8 were isolated for the first time from the genus Schefflera. Their structures were elucidated by IR, UV, HR-ESI-MS, NMR 1D and 2D experiments, and comparison of their NMR data with previously reported data. Their α-glucosidase inhibition and cytotoxic activity against MCF-7 human breast cancer cell lines were evaluated. The isolates (1, 3–5, 8) showed stronger α-glucosidase inhibitory activity (IC₅₀ = 5.99–76.58 μM) than the standard drug acarbose (IC₅₀ = 214.50 μM). At the concentration of 100 μg/ml, the isolates (1, 2) showed appreciable cytotoxic activity (67.92, 63.83%, respectively).     

A new lignan from <Emphasis Type="Italic">Aphanamixis polystachya</Emphasis>

A new lignan, polystachyol (1), two lignan glycosides, lyoniside (2) and nudiposide (3), and a sterol, ergosta-4,6,8(14),22-tetraen-3-one (4), with stigmasterol, and oleic and linoleic acids, have been isolated from an MeOH extract of the dried bark of Aphanamixis polystachya. The structures of the isolated compounds were elucidated by analysis of 1D and 2D NMR and mass spectroscopic data. The compounds did not have growth inhibitory activity against HeLa cells.     

A new ganoderic acid from Ganoderma lucidum mycelia

A new ganoderic acid (GA), 7-O-ethyl ganoderic acid O (GA-O) (1), together with two known compounds, GA-T (2) and GA-Me (3), was isolated and purified from fermented mycelia of Ganoderma lucidum. The structure of the new triterpenoid was elucidated on the basis of the interpretation of extensive spectroscopic data (HR-MS, IR, UV, 1D and 2D NMR) as 3α,15α,22-triacetoxy-7α-ethoxy-5α-lanost-8,24E-dien-26-oic acid. The new compound was found to contain a rare ethoxyl group at C-7. In addition, its cytotoxicity against 95D and HeLa human cancer cell lines was also evaluated.     

Metabolites from endophytic fungus A12 of Dracaena cambodiana

A new drimane sesquiterpene, 1α,7α-dihydroxyconfertifolin (1), along with two known compounds 2 and 3, was isolated from endophytic fungus A12 of Dracaena cambodiana. The new compound was elucidated by HR-ESI-MS and spectroscopic techniques (IR, UV, 1D, and 2D NMR). Compound 2 showed inhibitory bacterial activity against Staphylococcus aureus with diameter of the inhibition zone of 13.5 mm.     

Diterpenoids from the roots of Euphorbia fischeriana and their inhibitory effects on α-glucosidase

Abstract

Chemical investigation has been performed on the roots of Euphorbia fischeriana, a traditional Chinese medicine. Three diterpenoids were obtained using various chromatographic techniques, and their structures were determined by spectroscopic data including HRESIMS, 1D NMR, 2D NMR, ECD, and calculated ECD, which gave two new diterpenoids, daphnane type (1) and ent-pimarene type (3). Additionally, the isolated compounds (1–3) displayed moderate inhibitory effects against α-glucosidase in an in vitro bioassay.     

Chemical characteristics of the fungus Ganoderma lucidum and their inhibitory effects on acetylcholinesterase

Abstract

The chemical characteristic of a well-known folk medicine Ganoderma lucidum has been investigated by a series of chromatographic technologies, which displayed the presences of 45 lanostane type triterpenoids, including two new nor-lanostane triterpenoids (40, 41). Their structures were identified on the basis of spectroscopic data analysis (UV, IR, HRESIMS, 1D, and 2D NMR). Notably, some triterpenoids displayed moderate inhibitory effects against AChE (acetylcholinesterase) by an in vitro screened experiment. Triterpenoid 2 displayed the potent inhibitory effect with IC₅₀ 10.8 and K_i 14.95 μM (inhibition kinetic). The preliminary SAR has been discussed by the docking analyses between ganoderic acids (1, 2) and AChE.     

Four new taraxastane-type triterpenoic acids from Cirsium setosum

Four new taraxastane-type triterpenoids acids 3β,22α-dihydroxy-20-taraxasten-30-oic acid (1), 3β-hydroxy-22-oxo-20-taraxasten-30-oic acid (2), 3-oxo-22α-hydroxy-20- taraxasten-30-oic acid (3), and 3β,19β-dihydroxy-20-taraxasten-30-oic acid (4) were isolated and characterized from Cirsium setosum (Willd.) MB. Their structures were determined by the combination of 1D and 2D NMR experiments (¹H-¹HCOSY, HSQC, HMBC and ROESY) and mass spectrometry. Compound 2 exhibited potent selective cytotoxicity against human ovarian cancer cell line A2780 with an IC₅₀ value of 3.9 μM.