Intracellular mechanisms for the decomposition of a lipid peroxide. I. Decomposition of a lipid peroxide by metal ions, heme compounds, and nucleophiles

Abstract

Linoleic acid hydroperoxide was prepared. Two types of mechanisms for its decomposition were found. The hydroperoxide was rapidly decomposed by certain transition metal ions, heme, and hemoprotein to a complex range of products, the decomposition being accompanied by changes in ultraviolet absorption spectra. The production of radical oxidizing species may account for these products. It was also found that the hydroperoxide could be decomposed by nucleophiles presumably in a nonradical reaction to a hydroxy acid without any change in ultraviolet spectra.The kinetics, the pH dependence, and the effects of metal-complexing agents, inhibitors, and hydrogen donors on the catalytic activity of the metal ions and heme compounds were also investigated.