绿原酸协同抗氧化机理的电化学和光谱-色谱学研究

Study on the Synergistic Antioxidant Mechanism of Chlorogenic Acids(CQAs)with Electrochemical and Spectroscopy Property

利用循环伏安法、油水分配系数和红外光谱(FTIR)、XRD射线粉末衍射以及圆二色谱(CD)对于绿原酸协同抗氧化的机理进行了研究,并通过ABTS自由基清除能力对于绿原酸单体和复配混合物的抗氧化活性进行了测定。结果表明,复配绿原酸分子之间抗氧化活性差距越大,抗氧化活性高的绿原酸含量越高,协同效果越好;协同过程中并未发现绿原酸复配混合物氧化电势的改变,说明协同作用时分子间的氧化偶联作用并不存在;转移电量与抗氧化指标之间具有很高的相关性(0.92),协同作用发生时体系的实际转移电量高于理论转移电量,证明了高抗氧化活性绿原酸分子即双咖啡酰奎宁酸的重生;油水分配系数绝对值差为0.13时的绿原酸复配组合具有良好的界面效应和高的协同效果;红外光谱、XRD射线粉末衍射以及圆二色谱并未发现绿原酸复配混合物中反映绿原酸分子相互作用和规则性排列的信息。因此绿原酸分子之间重生机制和体系的界面效应是绿原酸发生协同抗氧化现象的主要原因。

The synergistic antioxidant mechanism of chlorogenic acids（CQAs） was studied in this paper through cyclic voltammograms（CV）,oil-water partition coefficient（P）,FT-IR,XRD and circular dichroism（CD）.The antioxidant capability of CQAs isomers and their mixture was determined by using ABTS free radical quenching ability assay.The results showed that the bigger the antioxidant activity disparity between the CQAs molecules was,the higher the content of high antioxidant activity CQAs was,the better the synergistic effect of the CQAs combination mixture became;The oxidation potential（E（pa）） of CQAs combination mixture kept constant in the synergistic experiments,which indicted the oxidative coupling interaction don＇t exist between the CQAs;The charge transferred（Q） and antioxidant activity exhibited high correlation（0.92）;the practical Q was higher than the theoretical Q in the synergistic process and this confirmed that the CQAs（dicaffeoylquinic acids） regeneration of high antioxidant activity happened;the CQAs mixture with the absolute difference value of oil-water partition coefficient of 0.13 gave the good interface effect and high synergistic degree;the interaction and the regular arrangement between the CQAs combination were not discovered through FT-IR,XRD and CD.Therefore,the regeneration mechanism of CQAs molecules and the interface effect of reaction system were the main cause of the phenomenon of the synergistic antioxidant of CQAs.