Ascorbate autoxidation in the presence of iron and copper chelates.
Chelates can inhibit the iron- and copper-catalyzed autoxidation of ascorbate at pH 7.0. Diethylenetriaminepentaacetic acid (DTPA or DETAPAC) and Desferal (deferoximane mesylate) slow the iron-catalyzed oxidation of ascorbate as effectively as reducing the trace levels of contaminating iron in buffers with Chelex resin. DETAPAC, EDTA and HEDTA (N-(2-hydroxyethyl)-ethylenediaminetriacetic acid) are effective at slowing the copper-catalyzed autoxidation of ascorbate while Desferal is ineffective. The ability to inhibit ascorbate autoxidation appears to parallel the rate of the reaction of superoxide with the iron chelate.
Buettner
G R
GR
GSF (Gesellschaft für Strahlen- und Umweltforschung), Abteilung für Strahlenbiologie, Neuherberg, F.R.G.
D001205:Ascorbic Acid / Q000378:metabolism*; D002411:Cation Exchange Resins / Q000378:metabolism; D002614:Chelating Agents / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D003676:Deferoxamine / Q000378:metabolism; D004492:Edetic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D007502:Iron Chelating Agents / Q000378:metabolism*; D010084:Oxidation-Reduction; D004369:Pentetic Acid / Q000378:metabolism; D012117:Resins, Synthetic; D013481:Superoxides / Q000378:metabolism
D002411:Cation Exchange Resins; D002614:Chelating Agents; D007502:Iron Chelating Agents; D012117:Resins, Synthetic; D013481:Superoxides; C024997:Chelex 100; D003300:Copper; D004369:Pentetic Acid; D004492:Edetic Acid; D003676:Deferoxamine; D001205:Ascorbic Acid; C026060:N-(hydroxyethyl)ethylenediaminetriacetic acid