二氢硫辛酸抗氧化性机理的理论研究  

Theoretical study on antioxidant activity of dihydrolipoic acid

作　　者：陈婷[1] 杨祥[1] 周朝昕[1] 杨云[1] 童烁云[1] 

机构地区：[1]中国地质大学(武汉)材料与化学学院,湖北武汉430074

出　　处：《分子科学学报》2014年第1期40-45,共6页Journal of Molecular Science

基　　金：中国地质大学(武汉)中央高校基本科研业务费专项资金资助项目(CUGL110202)

摘　　要：分别在B3LYP/6-31G(d,p)和B3LYP/6-311++G(d,p)水平下,对二氢硫辛酸及可能的解离途径中形成的自由基进行结构优化,采用S—H键解离焓(EBD)和分子的电离势(EIP)为理论指标,探讨了二氢硫辛酸可能的抗氧化性机理,并研究了溶剂(水和苯)效应的影响.结果表明,C(1)上S—H断裂形成的自由基b较易形成;以EBD和EIP为理论指标,可以较好的说明分子的抗氧化性及溶剂效应对抗氧化性的影响.随着溶剂的极性增加,EBD变化较小,而EIP则显著减小,表明溶剂效应对清除自由基的电子转移反应机理影响更大.分子最高占据轨道HOMO能级顺序与EIP数值所预测的抗氧化性顺序一致.Theoretical study at B3LYP/6-31G （d, p） and B3LYP/6-311 ＋ ＋ G （d, p） was conducted in order to explain the mechanism of antioxidant activity of dihydrolipoic acid. S H bond dissociation enthalpy （EBD） and ionization potential （IP） were selected as theoretical indexes to evaluate the ability of free radical scavenging. Solvent effect was studied by choosing water and benzene as solvents. The result showed that free radical b was easy to form, and with the increasing of ionization potential of the solvent, EBD remained almost unchanged, while IP decreased rapidly. Solvent effect had greater impact on the electron transfer mechanism. The HOMO energy gave the same antioxidant activity subsequence as indicated by IP.

关 键 词：二氢硫辛酸 抗氧化性 密度泛函 理论研究 

分 类 号：O641[理学—物理化学]