Tea catechins and flavonoids from the leaves of Camellia sinensis inhibit yeast alcohol dehydrogenase
作者:Md. Maniruzzaman Manir、Jeong Kee Kim、Byeong-Gon Lee、Surk-Sik Moon
DOI:10.1016/j.bmc.2012.02.002
日期:2012.4
Four new quercetin acylglycosides, designated camelliquercetisides A-D, quercetin 3-O-[alpha-L-arabinopyranosyl(1 -> 3)][2-O ''-(E)-p-coumaroyl][beta-D-glucopyranosyl(1 -> 3)-alpha-L-rhamnopyranosyl(1 -> 6)]-beta-D-glucoside (17), quercetin 3-O-[2-O ''-(E)-p-coumaroyl][beta-D-glucopyranosyl(1 -> 3)-alpha-L-rhamnopyranosyl(1 -> 6)]-beta-D-glucoside (18), quercetin 3-O-[alpha-L-arabinopyranosyl(1 -> 3)][2-O ''-(E)-p-coumaroyl][alpha-L-rhamnopyranosyl(1 -> 6)]-beta-D-glucoside (19), and quercetin 3-O-[2-O ''-(E)-p-coumaroyl][alpha-L-rhamnopyranosyl(1 -> 6)]-beta-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 IC50 8.0-70.3 mu M, and radical scavenging activities in the range of IC50 1.5-43.8 mu M, measured by using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical. (C) 2012 Elsevier Ltd. All rights reserved.