RADICAL-CAPTURING REACTION AND ITS REACTION MECHANISM OF QUERCETIN REPRESENTING FLAVONOIDS

继去年研究了3,5,7-三甲基槲皮素和3,7-二甲基非西汀对合成自由基2,2'-偶氮-二丁基腈（AIBN）的自由基捕获机理后，本文又进行了槲皮素和/或环二醇在不同pH、反应溶剂和温度等条件下对1,1-二苯基-2-吡啶肼（DPPH）和/或galvinoxyl的自由基捕获反应，以了解自由基捕获反应的实际情况。根据不同的pH值，使用多种缓冲溶液进行实验，得到如下结果：结果表明，槲皮素和戊二醇在酸性条件下比在碱性条件下捕获dpph的能力更强。与DPPH相反，这两种黄酮类化合物在碱性条件下捕获galvinoxy2的能力更活跃。通过采用甲醇、乙醇和丙酮等多种反应溶剂进行实验，推测槲皮素和戊二醇捕获DPPH-和galvinoxyl的能力主要受反应时间的影响，而不是受反应溶剂的影响。改变反应温度的实验表明，槲皮素捕获DPPH-和galvinoxyl的能力与反应温度有关，但能力的增加趋势并不超出我的预期。然而，在这项工作中，由于时间的限制，我没有得到关于周期二醇的数据。综上所述，尽管今年的实验还不够，但还是有以下观点。为了有效地利用抗氧化成分，了解抗氧化剂和目标自由基的化学生化性质，并考虑反应场的条件是最重要的。然后，找出各种抗氧化剂使用的固有条件。

Following the study on the radical-capturing reaction mechanism of 3,5,7-trimethyiquercetin and 3,7-dimethylfisetin against a synthetic radical of 2,2'-azobis-isabutylnitrile ( AIBN) in the last year, the reactions of quercetin and/or eriodictyol against 1,1-diphenyl-2-picrylhydrazil (DPPH) and/or galvinoxyl under various conditions such as pH, reaction solvent and temperature were undertaken in order to understand the actual condition on radical-capturing reactions.From the experiments using plural buffer solutions depending upon different pH, the results were obtained as below. It was revealed that DPPH-capturing abilities of quercetin and eriodictyol were more active in the acidic condition compared to the alkaline condition. Contrary to those of DPPH, galvinoxyl-capturing abilities of both flavonoids were more active in alkaline condition. From the experiments using plural reaction soluvents such as methanol, ethanol and acetone, it was presumed that DPPH- and galvinoxyl-capturing abilities of quercetin and eriodictyol were mainly influenced by reaction time, not reaction solvents. The experiments while changing reaction temperature were indicated that DPPH- and galvinoxyl-capturing abilities of quercetin depended the reaction temperature, though the increasing tendency of abilities was little beyond my expection. Still, in this work, the data on eriodictyol were not obtained, because I was restricted by time.From the above, the following view was led, though the experiments in this year were not enough. For the purpose of efficacious utilization of antioxidative constituents, there were the most important things to understand the chemical and biochemical properties of antioxidant and target radicals and to consider the conditions of the reaction field. And then, it can be found out the inherent condition for the use of each antioxidant.