- Synthesis of various kinds of isoflavones, isoflavanes, and biphenyl- ketones and their 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activities
-
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=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.
- Goto, Hideyuki,Terao, Yoshiyasu,Akai, Shuji
-
experimental part
p. 346 - 360
(2009/12/27)
-
- Synthesis of Naturally Occuring 6,7-Dimethoxy-3',4'-methylenedioxyisoflavanone and its Analogues
-
6,7-Dimethoxy-3',4'-methylenedioxyisoflavanone (6a) isolated from the heartwood of Cordyla africana has now been synthesized by the Hoesch condensation of hydroxyquinol (1) with 3,4-methylenedioxybenzyl cyanide (2a) and partial methylation.The related iso
- Jain, Amolak C.,Prasad, Ashok K.
-
p. 622 - 624
(2007/10/02)
-