title: Isolation and identification of metabolites from dihydromyricetin.
abstract: Dihydromyricetin (DHM) is the major bioactive constituent of Rattan Tea, which is the tender stems and leaves of Ampelopsis grossendentata. Seven metabolites (2-8) of DHM (1) were obtained by the chromatographic method. The metabolites 2-5 were obtained from the urine of rats administered orally with DHM; and metabolites 6-8 were detected in the fecal specimens of rats, which were also produced by human intestinal bacteria (HIB) in vitro, and were separated from the cultured media of HIB containing DHM. Their structures were elucidated as 5,7,3',5'-tetrahydroxyflavanonol (2); 5,7,3',5'-tetrahydroxy-4'-methoxyflavanonol (3); 5,7,4',5'-tetrahydroxy-3'-methoxyflavanonol (4); and dihydromyricetin-O-5-beta-D-glucuronide (5); (2R,3S)-5,7,3',4',5'-pentahydroxyflavanonol (6); 3,4,5,7,3',4',5'-hepthydroxyflavan (7) and 5,7,3',4',5'-pentahydroxyflavanone (8) on the basis of UV, NMR and LC-MS/MS data. These seven metabolites were formed through familiar metabolic reactions. Dihydromyricetin-O-5-beta-D-glucuronide (5) is a new compound. The (13)C-NMR data of (2) and (4) are reported for the first time.
authors.affiliation: Department of Natural Medicines and State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, No. 38 Xueyuan Road, Beijing 100083, P. R. China.
authors.forename: Yansong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Sheng
authors.initials: S
authors.lastname: Que
authors.forename: Xiuwei
authors.initials: X
authors.lastname: Yang
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Liang
authors.initials: L
authors.lastname: Qiao
authors.forename: Yuying
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D044948:Flavonols / Q000032:analysis / Q000378:metabolism*; D020719:Glucuronides / Q000032:analysis / Q000378:metabolism; D008297:Male; D013058:Mass Spectrometry; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D013056:Spectrophotometry, Ultraviolet
chemical_list: D044948:Flavonols; D020719:Glucuronides; C472036:dihydromyricetin