Zhang Cen, Zhang Guowen, Liao Yijing, Gong Deming
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, China.
Food Chem. 2017 Apr 15;221:1569-1577. doi: 10.1016/j.foodchem.2016.10.136. Epub 2016 Oct 31.
Myricetin, a plant-derived flavonol, was found to inhibit the formation of uric acid in a mixed-type manner with IC value of (8.66±0.03)×10molL and more potently inhibit the generation of superoxide anion (O) catalysed by xanthine oxidase (XOD) with IC value of (4.55±0.02)×10molL. Inhibiting O generation by myricetin may be attributed to the reduced form of XOD with a substantially higher reduction potential for FADH/FADH 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 out of the FAD site, resulting in the transfer of another electron from FADH to O 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.
杨梅素是一种植物来源的黄酮醇，被发现以混合型方式抑制尿酸形成，其半数抑制浓度（IC）值为(8.66±0.03)×10⁻⁵mol/L，并且更有效地抑制黄嘌呤氧化酶（XOD）催化的超氧阴离子（O₂⁻）生成，IC值为(4.55±0.02)×10⁻⁵mol/L。杨梅素抑制O₂⁻生成可能归因于XOD的还原形式，其FADH₂/FAD电对具有更高的还原电位。此外，分子对接证实杨梅素结合到黄素腺嘌呤二核苷酸（FAD）结构域中异咯嗪环周围的位点，以阻止O₂⁻从FAD位点扩散出去，导致另一个电子从FADH₂转移到O₂⁻形成过氧化氢。这项研究为杨梅素在抑制XOD催化中的作用提供了新的见解，这可能有利于提高杨梅素在功能性食品中的潜在应用。
