Fe(III)-coordination properties of neuromelanin components: 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid.
Journal Article (Journal Article)
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.
Full Text
Duke Authors
Cited Authors
- Charkoudian, LK; Franz, KJ
Published Date
- May 2006
Published In
Volume / Issue
- 45 / 9
Start / End Page
- 3657 - 3664
PubMed ID
- 16634598
Electronic International Standard Serial Number (EISSN)
- 1520-510X
International Standard Serial Number (ISSN)
- 0020-1669
Digital Object Identifier (DOI)
- 10.1021/ic060014r
Language
- eng