期刊名称：Journal of Clinical Biochemistry and Nutrition
印刷版ISSN：0912-0009
电子版ISSN：1880-5086
出版年度：2008
卷号：42
期号：1
页码：50-53
DOI：10.3164/jcbn.2008008
出版社：The Society for Free Radical Research Japan
摘要：Previously, we identified four metabolites of (−)-epicatechin in blood and urine: (−)-epicatechin-3'- O -glucuronide (E3'G), 4'- O -methyl-(−)-epicatechin-3'- O -glucuronide (4'ME3'G), (−)-epicatechin-7- O -glucuronide (E7G), and 3'- O -methyl-(−)-epicatechin-7- O -glucuronide (3'ME7G) (Natsume et al. Free Radical Biol. Med. 34, 840-849, 2003). The aim of the current study was to compare the antioxidative activities of these metabolites with that of their parent compound. After oral administration of (−)-epicatechin, E3'G and 4'ME3'G were isolated from human urine, and E7G and 3'ME7G isolated from rat urine. We found that these compounds inhibited peroxynitrite-mediated tyrosine nitration, in the following order of potency: E3'G > (−)-epicatechin > E7G = 3'ME7G. = 4'ME3'G. These results demonstrate that the metabolites of (−)-epicatechin retain antioxidative activity on peroxynitrite-induced oxidative damages to some extent.
