多巴氧化生成黑色素过程中锰和铝协同作用的紫外可见光谱研究  

UV-Vis Spectroscopic Study of Aluminum-Manganese Cooperative Effect on the Melanin Formation from DOPA Oxidation

作　　者：狄俊伟[1] 毕树平[1] 

机构地区：[1]南京大学化学系

出　　处：《光谱学与光谱分析》2005年第1期83-85,共3页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金(20075011)资助项目

摘　　要：采用紫外可见光谱法研究了铝和锰离子在多巴氧化生成黑色素过程中的作用。实验结果表明在pH55的弱酸性缓冲溶液中,锰和铝离子对多巴氧化生成黑色素的过程具有协同催化作用。铝不是过渡金属,本身不能启动氧化作用。锰离子可启动多巴的氧化,生成中间体多巴色素。铝离子可催化多巴色素转化为5,6二羟基吲哚的反应,它是黑色素形成过程中很重要的一步反应,其产物可进一步氧化并聚合生成黑色素。因此,锰和铝离子的协同作用促进了多巴氧化生成黑色素,增加了体系的氧化压力。The effect of aluminum and manganese ions on the melanin formation from oxidized DOPA was investigated by UV-Vis spectroscopy. In the weak acidic buffer solution (pH 5.5), aluminum and manganese ions have cooperative effect on the melanin formation. Aluminum is not a transition metal and therefore cannot initiate oxidative effect. However, manganese ions initiate the oxidation of DOPA to yield dopachrome. Aluminum ions can greatly catalyze the conversion reaction of dopachrome to form 5,6-dihydroxyindole, which is a key step in the biosynthesis of melanin. Its product is further oxidized and polymerized immediately to produce melanin. Therefore, the cooperative effect of manganese and aluminum ions increases the melanin formation from DOPA and enhances the oxidative stress.

关 键 词：黑色素 多巴 氧化压力 协同作用 生成 反应 形成过程中 聚合 中间体 二羟基 

分 类 号：O641.3[理学—物理化学] R446.12[理学—化学]