Structure–activity relationship studies of flavonoids as potent inhibitors of human platelet 12-hLO, reticulocyte 15-hLO-1, and prostate epithelial 15-hLO-2
作者:Yesseny Vasquez-Martinez、Rachana V. Ohri、Victor Kenyon、Theodore R. Holman、Silvia Sepúlveda-Boza
DOI:10.1016/j.bmc.2007.07.036
日期:2007.12
Human lipoxygenase (hLO) isozymes have been implicated in a number of disease states and have attracted much attention with respect to their inhibition. One class of inhibitors, the flavonoids, have been shown to be potent lipoxygenase inhibitors but their study has been restricted to those compounds found in nature, which have limited structural variability. We have therefore carried out a comprehensive study to determine the structural requirements for flavonoid potency and selectivity against platelet 12-hLO, reticulocyte 15-hLO-1, and prostate epithelial 15-hLO-2. We conclude from this study that catechols are essential for high potency, that isoflavones and isoflavanones tend to select against 12-hLO, that isoflavans tend to select against 15-hLO-1, but few flavonoids target 15-hLO-2. (C) 2007 Elsevier Ltd. All rights reserved.
US4814346A
申请人:——
公开号:US4814346A
公开(公告)日:1989-03-21
Synthesis of Various Kinds of Isoflavones, Isoflavanes, and Biphenyl-Ketones and Their 1,1-Diphenyl-2-picrylhydrazyl Radical-Scavenging Activities
作者:Hideyuki Goto、Yoshiyasu Terao、Shuji Akai
DOI:10.1248/cpb.57.346
日期:——
Forty-eight kinds of isoflavones (8), thirty-one isoflavanes (9), and forty-seven biphenyl-ketones (10, 10′) were synthesized from eleven kinds of substituted phenols (11) and six phenylacetic acids (12). Among them, seventy-five compounds are new. The radical scavenging activities of these compounds were evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) at pH 6.0. We found that thirty-nine out of forty-three compounds having a catechol moiety on either the A- or the B-ring exhibited a high activity (ED50=12—54 μM) similar to that of catechin. In these cases, the remaining part of their structure seemed to have little effect on their activity. Many 6- or 8-hydroxyisoflavanes (9E—I) and their biphenyl-ketone derivatives (10E—H) also showed a high activity (ED50=<50 μM), while all of their corresponding isoflavones (8E—I) were not active at all. The 7-hydroxyisoflavanes having either an additional hydroxyl group at the C5-position (9D) or a methoxy group at the C6-position (9J) presented a high activity (ED50=26—32 μM). This study suggests that natural isoflavones have the possibilities of exhibiting antioxidant activities through the hydroxylation at the C6-, C8-, or C3′-position or the formation of the isoflavanes (9) and/or the biphenyl-ketone derivatives (10′) by metabolism or biotransformation.