Novel Kinetic Method for Expressing the Ability of Antioxidant to Scavenge Radicals

作     者：LI Yan-feng LI Pei-ze LIU Zai-qun 

作者机构：Department of Organic Chemistry College of Chemistry Jilin University Changehun 130012 t~ R. China 

出 版 物：《Chemical Research in Chinese Universities》 (高等学校化学研究（英文版）)

年 卷 期：2013年第29卷第5期

页      面：947-951页

核心收录：

学科分类：0832[工学-食品科学与工程（可授工学、农学学位）] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 070303[理学-有机化学] 0703[理学-化学] 083201[工学-食品科学] 

基　　金：Supported by the Jilin Provincial Science and Technology Department 

主　　题：Rate constant Radical-scavenging ability Antioxidant capacity Chemical kinetics 

摘      要：A method was developed to treat the result from an antioxidant trapping radicals including 2,2＇-azinobis （3-ethylbenzothiazoline-6-sulfonate） cationic radieal（ABTS＋＇）, 2,2＇-diphenyl-l-picrylhydrazyl radical（DPPH）, and galvinoxyl radical. In the presence of a certain concentration of an antioxidant, the decrease of the concentration of a kind of radicals follows the second order exponential function with the increase of the reaction time（t）, v＆., [radical]=Ae-t/a＋Be rib＋c, the derivation operation of which obtains the differential style, -d[radical]/dt= （A/a）e t/a＋（B/b）e-t/b, revealing the relationship between the reaction rate（r=-d[radical]/dt） and the reaction time（t）. Thus, the reaction rate at the beginning of the reaction@0） can be calculated by assigning t=-0 in the equation of -d[radical]/dt-t. Based on the concept of the reaction rate, r=k[radical][antioxidant], the rate constant（k） can be calculated based on r0 and the initial concentrations of radical and antioxidant, k=-r0/（[radieal]o[antioxidant]0）. The k means the rate of a fresh antioxidant molecule to trap a fresh radical. This method was used to treat the interactions of ABTS＋＇, DPPH, and galvinoxyl radicals with three homoisoflavonoids, four pyrazoles, and three ferrocenyl Schiff bases. It was found that ferrocenyl group is beneficial for antioxidants to reduce ABTS＋＇, and ortho-hydroxyl group is beneficial for antioxidants to donate hydrogen atom in phenolic hydroxyl group to DPPH and galvinoxyl radicals.