Fe(III)-coordination properties of neuromelanin components: 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid
Fe(III)-coordination properties of neuromelanin components: 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid
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DOI：
10.1021/ic060014r
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发表时间：
2006-05-01
影响因子：
4.6
通讯作者：
Franz, KJ
中科院分区：
文献类型：
--
作者：
Charkoudian, LK;Franz, KJ
通过厌氧pH依赖的分光光度滴定法，探讨了神经黑色素结构单元化合物5，6-二羟基吲哚（DHI）、5，6-二羟基吲哚-2-羧酸（DHICA）和5，6-二羟基-N-甲基-吲哚（Me-DHI）以及神经递质多巴胺在水溶液中的Fe（III）配位化学。的Fe（III）结合常数和pH值依赖的形态平行的邻苯二酚中，单，双，和三FeLx物种存在的浓度依赖于pH值。双FeL 2二羟基吲哚物种是有利的L = DHI和DHICA在中性至弱酸性条件下。DHI和DHICA在pH值为3至10时是比邻苯二酚、多巴胺和Me-DHI更强的Fe（III）螯合物。氧化研究表明，铁加速了DHI和DHICA的空气氧化。
The Fe(III)-coordination chemistry of neuromelanin building-block compounds, 5,6-dihydroxyindole (DHI), 5,6-dihydroxyindole-2-carboxylic acid (DHICA), and 5,6-dihydroxy-N-methyl-indole (Me-DHI), and the neurotransmitter dopamine were explored in aqueous solution by anaerobic pH-dependent spectrophotometric titrations. The Fe(III)-binding constants and pH-dependent speciation parallel those of catechol in that mono, bis, and tris FeLx species are present at concentrations dependent on the pH. The bis FeL2 dihydroxyindole species are favorable for L = DHI and DHICA under neutral to mildly acidic conditions. DHI and DHICA are stronger Fe(III) chelates than catechol, dopamine, and Me-DHI at pH values from 3 to 10. Oxidation studies reveal that iron accelerates the air oxidation of DHI and DHICA.