Journal of Organometallic Chemistry, April 15, 2015, Vol.782, p.103(8)
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jorganchem.2015.01.005 Byline: 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. Author Affiliation: (a) Division of Molecular Systems Biology, Department of Ecogenomics and Systems Biology, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, Vienna A-1090, Austria (b) Plant Biochemistry, Albrecht-von-Haller Institut, Georg-August-Universitat Gottingen, Justus-von-Liebig-Weg 11, Gottingen D-37077, Germany Article History: Received 17 October 2014; Revised 7 January 2015; Accepted 8 January 2015
Mass Spectrometry – Chemical Properties ; Mass Spectrometry – Comparative Analysis ; Metabolites – Chemical Properties ; Metabolites – Comparative Analysis ; Tryptophan – Chemical Properties ; Tryptophan – Comparative Analysis ; Nervous System Diseases – Chemical Properties ; Nervous System Diseases – Comparative Analysis ; Antioxidants (Nutrients) – Chemical Properties ; Antioxidants (Nutrients) – Comparative Analysis ; Monosaccharides – Chemical Properties ; Monosaccharides – Comparative Analysis
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