Kinetic evaluation of the reactivity of flavonoids as radical scavengers
Kinetic evaluation of the reactivity of flavonoids as radical scavengers
复制标题
DOI：
10.1080/1062936021000020071
复制
发表时间：
2002-10-01
影响因子：
3
通讯作者：
Kadoma, Y
中科院分区：
文献类型：
--
作者：
Fujisawa, S;Ishihara, M;Kadoma, Y
(T)he利用过氧化苯甲酰引发的甲基丙烯酸甲酯自由基聚合，在动力学考虑下研究了类黄酮作为自由基清除剂的反应性。每个苯酚分子捕获的自由基数量（化学计量因子，n值）按表没食子儿茶素-3-O-没食子酸酯（ECG）（5.5）>儿茶素（3.5）>白藜芦醇（2.4）>槲皮素（1.9）>没食子酸正丙酯（1.5）>橙皮素（1.0）的顺序降低。黄酮类化合物的抑制速率常数（k（inh））（I - 3 X 10（3）1/（mol s））彼此没有差异，因此，自由基清除活性取决于n值。利用PM 3半经验分子轨道计算方法，从前线轨道理论估算了黄酮类化合物完全氧化产物的n值。实验n值与计算值一致。
(T)he reactivity of flavonoids as radical scavengers was investigated under kinetic considerations using radical polymerization of methyl methacrylates initiated by benzoyl peroxide. The number of radicals which are trapped by each molecule of phenol (the stoichiometric factors, n values) decreased in the order of epigallocatechin-3-O-gallate (ECG) (5.5) > catechin (3.5) > resveratrol (2.4) > quercetin (1.9) > n-propylgallate (1.5) > hesperetin (1.0). The inhibition rate constants (k(inh)) (I - 3 X 10(3)1/(mol s)) for the flavonoids were not different from each other, and, therefore, the radical scavenging activity depend on n values. The n values of the fully oxidized flavonoids were estimated from the frontier orbital theory, using PM3 semiempirical molecular orbital calculation. The experimental n values were consistent with the calculated values.