Use of desferrioxamine as a ‘probe’ for iron-dependent formation of hydroxyl radicals

The iron chelator desferal is a powerful inhibitor of lipid peroxidation and of hydroxyl radical formation dependent on the presence of iron salts. Desferal also reacts with Superoxide radical with a second-order rate constant approximately equal to 3 × 102 M−1 at pH 10.2 and approximately 9 × 102 M−1 s−1 at physiological pH. It is concluded that this slow reaction of desferal with O2 − is unlikely to influence the interpretation of experiments in which the chelator is used. The ability of desteral to react with hydroxyl radical (k2 approximately 1010M−1s−1) is a far more likely source of error in the interpretation of results using this chelating agent.