title: Tea catechins and flavonoids from the leaves of Camellia sinensis inhibit yeast alcohol dehydrogenase.
abstract: Four new quercetin acylglycosides, designated camelliquercetisides A-D, quercetin 3-O-[α-L-arabinopyranosyl(1→3)][2-O″-(E)-p-coumaroyl][β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl(1→6)]-β-D-glucoside (17), quercetin 3-O-[2-O″-(E)-p-coumaroyl][β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl(1→6)]-β-D-glucoside (18), quercetin 3-O-[α-L-arabinopyranosyl(1→3)][2-O″-(E)-p-coumaroyl][α-L-rhamnopyranosyl(1→6)]-β-d-glucoside (19), and quercetin 3-O-[2-O″-(E)-p-coumaroyl][α-L-rhamnopyranosyl(1→6)]-β-D-glucoside (20), together with caffeine and known catechins, and flavonoids (1-16) were isolated from the leaves of Camellia sinensis. Their structures were determined by spectroscopic (1D and 2D NMR, IR, and HR-TOF-MS) and chemical methods. The catechins and flavonoidal glycosides exhibited yeast alcohol dehydrogenase (ADH) inhibitory activities in the range of IC(50) 8.0-70.3μM, and radical scavenging activities in the range of IC(50) 1.5-43.8 μM, measured by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical.
authors.affiliation: Department of Chemistry, Kongju National University, Gongju 314-701, Republic of Korea.
authors.forename: Md Maniruzzaman
authors.initials: MM
authors.lastname: Manir
authors.forename: Jeong Kee
authors.initials: JK
authors.lastname: Kim
authors.forename: Byeong-Gon
authors.initials: BG
authors.lastname: Lee
authors.forename: Surk-Sik
authors.initials: SS
authors.lastname: Moon
mesh_terms: D000426:Alcohol Dehydrogenase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D028241:Camellia sinensis / Q000737:chemistry*; D002392:Catechin / Q000737:chemistry* / Q000302:isolation & purification; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry* / Q000302:isolation & purification; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D018515:Plant Leaves / Q000737:chemistry; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology*; D013662:Tea / Q000737:chemistry
chemical_list: D004791:Enzyme Inhibitors; D005419:Flavonoids; D016166:Free Radical Scavengers; D013662:Tea; D002392:Catechin; D000426:Alcohol Dehydrogenase