title: The enzymatic oxidation of Desferal to a nitroxide free radical.
abstract: Desferrioxamine mesylate (Desferal), a transition metal ion chelator, has been used to inhibit the in vitro redox cycling of transition metal ions. ESR spectroscopy was utilized to detect and identify Desferal's one-electron oxidation product. We demonstrate that a horseradish peroxidase/H2O2 system, a xanthine oxidase/hypoxanthine system, and a hydroxyl radical-generating system are all capable of oxidizing Desferal to a nitroxide free radical. The same 9-line ESR spectrum (g = 2.0065, alpha N = 7.85 G, alpha H(2) = 6.35 G) was detected in all of the above systems. We, therefore, stress that care must be taken when using Desferal as a transition metal ion chelator to keep its concentration low enough to minimize these reactions, or to use a different metal ion chelator.
authors.affiliation: Laboratory of Molecular Biophysics, National Institute of Environmental Health Sciences, Research Triangle Park, NC 27709.
authors.forename: K M
authors.initials: KM
authors.lastname: Morehouse
authors.forename: W D
authors.initials: WD
authors.lastname: Flitter
authors.forename: R P
authors.initials: RP
authors.lastname: Mason
mesh_terms: D003676:Deferoxamine; D004578:Electron Spin Resonance Spectroscopy; D006735:Horseradish Peroxidase; D006861:Hydrogen Peroxide; D019271:Hypoxanthine; D007042:Hypoxanthines; D009589:Nitrogen Oxides; D010084:Oxidation-Reduction; D014969:Xanthine Oxidase
chemical_list: D007042:Hypoxanthines; D009589:Nitrogen Oxides; D019271:Hypoxanthine; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D014969:Xanthine Oxidase; C039900:nitroxyl; D003676:Deferoxamine