Enhancing effect of a cysteinyl thiol on the antioxidant activity of flavonoids and identification of the antioxidative thiol adducts of myricetin.
The enhancing effect of a cysteinyl thiol N-benzoylcysteine methyl ester on the antioxidant activity of several flavonoids was investigated in a lipid oxidation system. Obvious enhancement was apparent for catechin, myricetin, quercetin, and taxifolin, the activity for myricetin being the most potent among them. An HPLC analysis of the products from the antioxidation reaction of myricetin in the presence of the thiol was carried out and the structures of the products were determined to clarify the enhancing effect chemically. The obtained data indicated that two thiol adducts on the B ring, and probably C-ring adducts, which were produced in the antioxidation process, exerted an enhancing effect on the antioxidant activity of myricetin.
Graduate School of Integrated Arts and Sciences, University of Tokushima.
Toshiya
T
Masuda
Yukari
Y
Miura
Miyuki
M
Inai
Akiko
A
Masuda
D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D002392:Catechin / Q000737:chemistry; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D011794:Quercetin / Q000031:analogs & derivatives / Q000737:chemistry; D013438:Sulfhydryl Compounds / Q000737:chemistry / Q000378:metabolism
D000975:Antioxidants; D005419:Flavonoids; D013438:Sulfhydryl Compounds; C040015:myricetin; D002392:Catechin; D011794:Quercetin; C003377:taxifolin