FE(III) Coordination Properties of Neuromelanin Components: 5, 6- Dihydroxyindole and 5, 6- Dihydroxyindole-2-carboxylic Acid
Document Type
Journal Article
Role
Author
Publisher
American Chemical Society
Journal Title
Inorganic Chemistry
Volume
45
Issue
9
First Page
3657
Last Page
3664
Publication Date
5-1-2006
Abstract
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.
Repository Citation
Charkoudian, Louise and Franz, Katherine J., "FE(III) Coordination Properties of Neuromelanin Components: 5, 6- Dihydroxyindole and 5, 6- Dihydroxyindole-2-carboxylic Acid" (2006). Faculty Publications. Paper 526.