Iron chelation and redox chemistry of anthranilic acid and 3-hydroxyanthranilic acid

Author(s)
Vladimir Chobot, Franz Hadacek, Wolfram Weckwerth, Lenka Kubicova
Abstract

Anthranilic acid (ANA) and 3-hydroxyanthranilic acid (3-HANA) are kynurenine pathway intermediates of the tryptophan metabolism. A hitherto unemployed method combination, differential pulse voltammetry, mass spectrometry (nano-ESI–MS), deoxyribose degradation and iron(II) autoxidation assays has been employed for studying of their redox chemistry and their interactions with iron(II) and iron(III) ions. Both acids inhibited the Fenton reaction by iron chelation and ROS scavenging in the deoxyribose degradation assay. In the iron(II) autoxidation assay, anthranilic acid showed antioxidant effects, whereas 3-hydroxyanthranilic acid exhibited apparent pro-oxidant activity. The differential pulse voltammograms of free metabolites and their iron(II) coordination complexes reflected these properties. Nano-ESI–MS confirmed ANA and 3-HANA as efficient iron(II) chelators, both of which form coordination complexes of ligand:iron(II) ratio 1:1, 2:1, and 3:1. In addition, nano-ESI–MS analyses of the oxidation effects by hydroxyl radical attack identified 3-HANA as strikingly more susceptible than ANA. 3-HANA susceptibility to oxidation may explain its decreased concentrations in the reaction mixture. The presented observations can add to explaining why 3-HANA levels decrease in patients with some neurological and other diseases which can often associated with elevated concentrations of ROS.

Organisation(s)
External organisation(s)
Georg-August-Universität Göttingen
Journal
Journal of Organometallic Chemistry
Volume
782
Pages
103-110
No. of pages
8
ISSN
0022-328X
DOI
https://doi.org/10.1016/j.jorganchem.2015.01.005
Publication date
04-2015
Peer reviewed
Yes
Austrian Fields of Science 2012
104003 Inorganic chemistry, 106044 Systems biology, 104013 Natural product chemistry, 106025 Neurobiology
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/iron-chelation-and-redox-chemistry-of-anthranilic-acid-and-3hydroxyanthranilic-acid(f7936911-6dd5-4dd2-8a4a-dae2ebe29434).html