Myricetin inhibits the generation of superoxide anion by reduced form of xanthine oxidase

卷:221

Zhang, Cen ; Zhang, Guowen ; Liao, Yijing ; Gong, Deming

Nanchang Univ

关键词: Myricetin;    Xanthine oxidase;    Superoxide anion;    Inhibition;    Molecular simulation;   

DOI  :  10.1016/j.foodchem.2016.10.136

学科分类：食品科学和技术

【 摘 要 】

Myricetin, a plant-derived flavonol, was found to inhibit the formation of uric acid in a mixed-type manner with IC50 value of (8.66 +/- 0.03) x 10 (6) mol L (1) and more potently inhibit the generation of superoxide anion (O-2 ) catalysed by xanthine oxidase (XOD) with IC50 value of (4.55 +/- 0.02) x 10 (6) mol L (1). Inhibiting O-2 generation by myricetin may be attributed to the reduced form of XOD with a substantially higher reduction potential for FADH center dot/FADH(2) couple. Moreover, molecular docking verified that myricetin bound to the site around isoalloxazine ring in the flavin adenine dinucleotide (FAD) domain to block the diffusion of O-2 out of the FAD site, resulting in the transfer of another electron from FADH(2) to O-2 to form hydrogen peroxide. This study has provided new insight into the role of myricetin in inhibiting XOD catalysis, which may be beneficial to improve myricetin's potential application in functional foods. (C) 2016 Elsevier Ltd. All rights reserved.