硫辛酸抗氧化性溶剂效应的理论研究  

Theoretical study on antioxidant activity of lipoic acid-solvent effect

作　　者：陈婷[1] 杨祥[1] 周朝昕[1] 杨云[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：《化学研究与应用》2013年第4期572-575,共4页Chemical Research and Application

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：采用密度泛函方法,利用自洽反应场(SCRF)的Onsager模型,研究了正庚烷、苯、二氯甲烷、乙醇、二甲亚砜和水六种不同溶剂中硫辛酸分子的抗氧化性。以S-S键键解离焓(BDE)和分子电离势(IP)为理论指标评价了硫辛酸在六种溶剂中清除自由基的活性。发现随着溶剂的介电常数增大,BDE值几乎不变,而IP值则显著减小,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。溶剂的极性较小时,偏向于形成硫自由基的机理,而溶剂的极性较大时,偏向于电子转移机理。Antioxidant activity of lipoic acid in heptane,benzene, dichloromethane, alcohol, DMSO and water was studied by SCRFOnsager model using DFT method. The S-S bond dissociation enthalpy（BDE） and the ionization potential（IP） were selected as theoretical index to evaluate the ability of free radical scavenging. The result showed that with the increasing of ionization potential of solvent, BDE remained almost unchanged, while IP decreased rapidly. Solvent effect had greater impact on the electron transfer mechanism. The antioxidant mechanism of lipoic acid preferred to the sulfur radical reaction when the polarity of the solvent decreased and it preferred to the electron transfer mechanism when the polarity of the solvent increased.

关 键 词：硫辛酸 抗氧化性 密度泛函 溶剂效应 

分 类 号：O641.121[理学—物理化学]