Iron(II) salts in aqueous solution, or iron(III) salts in the presence of an O− 2 generating system, can activate dioxygen to produce hydroxyl radicals. These are detected indirectly by their ability to degrade deoxyribose with the formation of thiobarbituric acid-reactive (TBA) products. Iron salts also catalyse the peroxidation of phospholipids resulting in the formation of TBA-reactive products. Hydroxyl radicals were responsible for the degradation of deoxyribose but not for the observed peroxidation of phospholipid. The function of O− 2 in both deoxyribose degradation and phospholipid peroxidation seems to be that of reducing iron(III) into iron(II).
