title: Bio-assay guided isolation and identification of α-glucosidase inhibitors from the leaves of Aquilaria sinensis.
abstract: Eight α-glucosidase inhibitors including four new compounds were isolated from the 70% aqueous ethanolic extract of leaves of Aquilaria sinensis (Lour.) Gilg by activity-directed fractionation and purification processes. The ethanolic extract was first separated into petroleum ether, ethyl acetate, n-butanol and water soluble fractions and screened for inhibitory activity against α-glucosidase. Further activity-directed investigation lead to the isolation of four new compounds with moderate inhibitory activity, viz, aquilarisinin (1), aquilarisin (2), hypolaetin 5-O-β-D-glucuronopyranoside (3) and aquilarixanthone (4) from the n-butanol fraction, and four known compounds showing potent activity including mangiferin (5), iriflophenone 2-O-α-L-rhamnopyranoside (6), iriflophenone 3-C-β-D-glucoside (7) and iriflophenone 3,5-C-β-D-diglucopyranoside (8) from the most potent ethyl acetate fraction. The structures of these compounds were determined by extensive spectroscopic analyses, including IR, UV, ESIMS, HRESIMS, 1D and 2D NMR.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, Department of Natural Medicine, School of Pharmaceutical Sciences, Peking University, Beijing, PR China.
authors.forename: Jie
authors.initials: J
authors.lastname: Feng
authors.forename: Xiu-Wei
authors.initials: XW
authors.lastname: Yang
authors.forename: Ru-Feng
authors.initials: RF
authors.lastname: Wang
mesh_terms: D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D065089:Glycoside Hydrolase Inhibitors; D006027:Glycosides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018515:Plant Leaves / Q000737:chemistry; D013237:Stereoisomerism; D029645:Thymelaeaceae / Q000737:chemistry*
chemical_list: D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D065089:Glycoside Hydrolase Inhibitors; D006027:Glycosides