Di Junwei, Bi Shuping
Department of Chemistry, The State Key Laboratory of Coordination Chemistry of China, Nanjing University, 22 Hankou Road, Nanjing 210093, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2003 Nov;59(13):3075-83. doi: 10.1016/s1386-1425(03)00127-6.
A comparison between the effects of aluminum and cupric ions on the dopachrome (DC) conversion and the cooperation effect of the both ions in the DOPA oxidation to melanin pathway has been studied by UV-Vis spectrophotometric method. Both aluminum and cupric ions catalyze the DC conversion reaction, which is an important step in the melanin synthesis pathway. However, cupric ions catalyze the conversion of DC to yield 5,6-dihydroxyindole-2-carboxylic acid (DHICA) but the product of DC conversion catalyzed by aluminum is 5,6-dihydroxyindole (DHI). DOPA oxidation catalyzed by aluminum and cupric ions is studied in the presence of hydrogen peroxide. The results from our experiments provide evidence that aluminum can markedly increase the oxidative stress of copper-mediated the melanin formation and influence the properties of the melanin by means of changing the ratio of DHICA/DHI in the acidic environment (pH 5.5).
采用紫外可见分光光度法研究了铝离子和铜离子对多巴色素（DC）转化的影响，以及这两种离子在多巴氧化生成黑色素途径中的协同作用。铝离子和铜离子均催化DC转化反应，这是黑色素合成途径中的重要一步。然而，铜离子催化DC转化生成5,6-二羟基吲哚-2-羧酸（DHICA），而铝离子催化DC转化的产物是5,6-二羟基吲哚（DHI）。在过氧化氢存在的情况下，研究了铝离子和铜离子催化的多巴氧化反应。我们的实验结果表明，在酸性环境（pH 5.5）中，铝离子可显著增加铜介导的黑色素形成的氧化应激，并通过改变DHICA/DHI的比例来影响黑色素的性质。
