THE ACTION OF 9 CHELATORS ON IRON-DEPENDENT RADICAL DAMAGE

Nine iron chelators were tested in five systems for their effects on r adical-generation and conversion at chelator: iron molar ratios from 0 .1 to 10. Stimulatory actions might distinguish toxic from safer chela tors. Radical-generating reactions which represent different aspects o f iron (ferrous and ferric) availability were studied: a) the reaction with hydrogen peroxide to hydroxylate benzoate; b) the oxidation of a scorbate; c) the reaction with hydrogen peroxide to fragment proteins; d) the reaction with hydrogen peroxide to permit amplified chemilumin escence; and e) the induction of peroxidation of mitochondrial membran e lipids. The compounds used were HBED, CP130, Desferal, EDTA, pyridin e-hydrazone (CGP 43'902B), Ferrozine, CP 94 (CGP 46'700), L1 (CGP 37 3 91) and rhodotorulic acid (CGP 45 274). Only the hexadentate compounds HBED, CP130 and Desferal were uniformly inhibitory (''protective''). The protective compounds were also apparently more stable during radic al fluxes than the other chelators.