Study on chemical constituents of sponge-associated Aspergillus terreus / 药学实践杂志

Objective To study the chemical constituents of Aspergillus terreus from sponge epiphytic fungal. Methods Sephadex LH-20 column chromatography, silica gel column chromatography and high performance liquid chroma-tography were used to separate and purify the compounds. The structures of compounds were identified by spectroscopic data. The α-glucosidase inhibitory activity and antioxidant activity of the compounds were tested by PNPG and DPPH methods, respectively. Results Eight compounds were isolated from Aspergillus terreus and identified as methyl-3,4,5-trimethoxy-2-(2-(nicotinamido) benzamido) benzoate (1), terrelumamide A (2), emeheterone (3), (8R,9S)-dihydroisoflavipucine (4), (8S,9S)-dihydroisoflavipucine (5), cyclo(S-Pro-S-Phe) (6), brevianamide F (7), terrein (8). Compound 3 showed strong inhibitory activity against α-glucosidase and the IC50 value was 14.28 μmol/L. Conclusion Compounds 3, 4, 5, and 7 were obtained from Aspergillus terreus for the first time.

New furo3,2-hisochroman from the mangrove endophytic fungus Aspergillus sp. 085242 / 中国天然药物

Four new compounds, asperisocoumarin G (1), asperisocoumarin H (2), (±)-asperisocoumarin I [(±)-3], along with the known pergillin (4) and penicisochroman L (5) were isolated from a mangrove endophytic fungus Aspergillus sp. 085242 by further chemical investigation. The structures of the new compounds, including their absolute configurations, were established by analysis of HR-ESI-MS and NMR spectroscopic data, and ECD calculation. Asperisocoumarins G-I (1-3) were new isocoumarins belonging to the class of furo[3, 2-h]isocoumarins which are rarely found in natural sources. All of the isolated compounds were evaluated for their α-glucosidase inhibitory effects, and compounds 1 and 4 showed moderate α-glucosidase inhibitory activity, respectively. In an antimicrobial test, the racemate of 3 showed antibacterial activity against Salmonella.

Chemical constituents and their bioactivities from seeds of Clausena lansium / 中草药

Objective To study the chemical constituents and their biological activities of the seeds of Clausena lansium. Methods The compounds were isolated by various column chromatographic techniques including silica gel, Sephadex LH-20, semi-preparative HPLC, et al., and their structures were identified through a combined analysis of physicochemical properties, as well as NMR and MS data. The in vitro α-glucosidase inhibitory activity and nematicidal activity against Panagrellus redivivusl were screened by PNPG and Berman funnel methods, respectively. Results Eleven compounds were isolated and identified as (4R*,6R*)-6-hydroxypiperitone (1), (4S*,6R*)-6-hydroxypiperitone (2), (1S*,2S*,4R*)-1-methyl-4-(prop-l-en-2-yl) cyclohexane-1,2-diol (3), subamone (4), methyl (1R*,2R*,2’Z)-2-(5’-hydroxy-pent-2’-enyl)-3-oxo-cyclopentane acetate (5), 5-hydroxy-4-phenyl-5H-furan-2-one (6), loliolide (7), xylogranatinin (8), 2,6-dihydroxyhumula-3(12),7(13),9(E)-triene (9), xanthoxol (10), and ligballinol (11). Conclusion Compounds 1-8 are isolated from the genus for the first time, and compound 9 is first isolated from this species. Compound 8 showed strong α-glucosidase inhibitory activity, and compound 5 exhibited potent nematicidal activity.

Acylated kaempferol glycosides from flower buds of Panax ginseng and their α-glucosidase inhibitory activity / 中草药

Objective: To study the chemical constituents of flavonoids and its α-glucosidase inhibitory activity from the flower buds of Panax ginseng. Methods The compounds were isolated and purified by MCI gel, silica gel and semi-preparative HPLC chromatography, and the structures were elucidated based on the NMR and MS data. The α-glucosidase inhibitory activities of the isolated compounds in vitro were determined by 96-well microtiter plate. Results: From ethyl acetate fraction of alcohol extract of P. ginseng flower buds, five flavonoids were isolated and identified as kaempferol-3-O-(2″,3″-di-E-p-coumaroyl)-α-L-rhamnoside (1), kaempferol-3-O-(3″,4″-di-E-p-coumaroyl)-α-L-rhamnoside (2), kaempferol-3-O-(3″-Z-p-coumaroyl,4″-E-p-coumaroyl)-α-L-rhamnoside (3), kaempferol-3-O-(2″,4″-di-E-p-coumaroyl)-α-L-rhamnoside (4), and kaempferol-3-O-(2″,4″-di-Z-p-coumaroyl)-α-L-rhamnoside (5). The inhibitory activity of α-glucosidase in vitro showed that compound 3 had stronger inhibitory effect on α-glucosidase. Conclusion: Compounds 1-5 are isolated from this genus for the first time, and the phenylpropionyl acylated flavonol glycosides in P. ginseng flower buds have some inhibitory effect on α-glucosidase in vitro.

Studies on chemical constituents and activities of lignans and terpenes from stem of Moringa oleifera / 中草药

Objective: To study lignans and terpenes of Moringa oleifera Lam. Methods: The compounds were isolated and purified by various column chromatographic techniques and High Performance Liquid Chromatography (HPLC). The structures of the compounds were identified through the combined analysis of physicochemical properties and spectroscopic evidence. The antineoplastic activity, α-glucosidase and acetylcholinesterase inhibitory activity of compounds were evaluated by MTT method, PNPG method and Ellman colorimetric method, respectively. Results: Twelve compounds were isolated from M. oleifera by various chromatographic methods and were identified as lariciresinol (1), 3-(α,4-dihydroxy-3-methoxybenzyl)-4-(4-hydroxy-3- methoxybenzyl) tetrahydrofuran (2), (7S,8R)-dihydrodehydrodiconiferyl alcohol (3), macadiol (4), diethyl pinoresinol (5), pinoresinol (6), evofolin B (7), erythro-guaiacylglycerol-β-O-4’-dihydroconiferyl alcohol (8), tricyclohumuladiol (9), 9α-hydroxy-2β-methoxyclovane (10), 3β-hydroxy-oleana-11,13 (18)-dien-28-oic acid (11), oleanolic acid (12). Compounds 12 showed antineoplastic activity. Compound 1 and 2 exhibited α-glucosidase inhibitory activity. Conclusion: Compounds 1-11 are separated from Moringa Adans for the first time. This plant has the potential of developing functional product for their antineoplastic and α-glucosidase inhibitory activity.

A new eudesmane type sesquiterpene from cultivated Clerodendranthus spicatus in Hainan / 中国中药杂志

Six compounds were isolated from the aerial part of cultivated Clerodendranthus spicatus in Hainan with various chromatographic techniques,and their structures were determined as:1-dehydroxy-1-oxo-rupestrinol(1),N-trans-feruloyltyramine(2),methyl 3,4-dihydroxyphenyllactate(3),caffein acid(4),methyl caffeate(5) and ethyl caffeate(6),via analysis of physicochemical properties and spectroscopic evidence.Compound 1 was a new compound,while compounds 2 and 3 were isolated from C.spicatus for the first time.Biological activity results showed that compounds 2-4 exhibited α-glucosidase inhibitory activity with different inhibition ratio.

Vitellaria paradoxa nutshells from seven sub-Saharan countries as potential herbal medicines for treating diabetes based on chemical compositions, HPLC fingerprints and bioactivity evaluation / 中国天然药物

The aim of the study was to determine the feasibility of the Vitellaria paradoxa nutshell as a new medicinal resource for treating diabetes. A total of forty-one compounds were identified by HPLC-DAD-Q-TOF-MS and phytochemical methods in V. paradoxa nutshell methanol extract. Based on HPLC fingerprints, four characteristic constituents were quantified and the origin of twenty-eight V. paradoxa nutshells from seven sub-Saharan countries was compared, which were classified into three groups with chemometric method. Twenty-eight samples contained high total phenolic content, and exhibited moderate-higher antioxidant activity and strong α-glucosidase inhibitory activity. Furthermore, all fractions and isolated compounds were evaluated for their antioxidant and α-glucosidase inhibitory activities, and α-glucosidase inhibitory action mechanism of four characteristic constituents including protocatechuic acid, 3, 5, 7-trihydroxycoumarin, (2R, 3R)-(+)-taxifolin and quercetin was investigated via molecular docking method, which were all stabilized by hydrogen bonds with α-glucosidase. The study provided an effective approach to waste utilization of V. paradoxa nutshell, which would help to resolve waste environmental pollution and provide a basis for developing potential herbal resource for treating diabetes.

Structural characterization of polysaccharide from Cyclocarya paliurus leaves and its α-glucosidase inhibitory effect / 中草药

Objective: To extract and isolate polysaccharide from Cyclocarya paliurus leaves, characterize its structural features and study its α-glucosidase inhibitory effect. Methods: C. paliurus polysaccharide (CP50) was isolated and purified by water extraction and ethanol precipitation, deproteinization with 732 cation exchange resin and 50% ethanol precipitation. Molecular weight of CP50 was determined by high performance gel permeation chromatography-multiple angle laser light scattering (HPGPC-MALLS), and monosaccharide composition was analyzed by HPLC with PMP (1-phenyl-3-methyl-5-pyrazolone) pre-column derivatization. The structure of CP50 was characterized by methylation, Fourier transform infrared spectroscopy (FT-IR), and proton nuclear magnetic resonance spectrum (1H-NMR), respectively. The α-glucosidase inhibitory effect of CP50 was investigated by PNPG method. Results: The molecular weight of CP50 was 59 000. It contained eight kinds of monosaccharides including galacturonic acid, glucose, galactose, arabinose, mannose, xylose, rhamnose, and glucuronic acid with molar ratio of 29.1:25.6:16.5:9.3:6.7:6.1:4.1:2.6. CP50 was mainly composed of →4) GalA (1→, →4) Glc (1→ and →4) Gal (1→ with branches at C-6 position of galactose. Furthermore, our results showed that CP50 exhibited a potent inhibitory effect on α-glucosidase, and the value of IC50 was determined to be 3.3 μg/mL which was much lower than the anti-type 2 diabetes drug acarbose (193.6 μg/mL). The inhibitory mode belongs to the mixed noncompetitive inhibition. Conclusion: CP50 is a pectin-like acidic polysaccharide with complex structure. Moreover, CP50 possesses better α-glucosidase inhibitory effect and potential value for the drug development and utilization.