Mukai K, Fukuda K, Ishizu K
Department of Chemistry, Faculty of Science, Ehime University, Matsuyama, Japan.
Chem Phys Lipids. 1988 Jan;46(1):31-6. doi: 10.1016/0009-3084(88)90110-7.
Second-order rate constants, kappa s, for H-atom abstraction by phenoxyl radicals from five tocopherol (vitamin E) derivatives have been measured spectrophotometrically at 25.0 degrees C by the stopped-flow method, as a model reaction of tocopherols with unstable free radicals (LOO., LO., and HO.) in biological systems. Three new tocopherol derivatives with a five-membered heterocyclic ring were found to be 1.9-2.1 times more active than the alpha-tocopherol which has the highest antioxidant activity among natural tocopherols. The proton hyperfine splittings for the five tocopheroxyl radicals derived from these tocopherols by the reaction with phenoxyl were also determined by ESR measurements.
通过停流法在25.0摄氏度下用分光光度法测定了苯氧自由基从五种生育酚（维生素E）衍生物中夺取氢原子的二级速率常数κ，以此作为生物系统中生育酚与不稳定自由基（LOO·、LO·和HO·）反应的模型。发现三种带有五元杂环的新型生育酚衍生物的活性比α-生育酚高1.9至2.1倍，α-生育酚是天然生育酚中抗氧化活性最高的。还通过电子自旋共振（ESR）测量确定了这些生育酚与苯氧自由基反应生成的五种生育酚氧基自由基的质子超精细分裂。
