Observations on the decomposition of hemin by fatty acid hydroperoxides.

Abstract

DiscussionThe destruction of hemin by hydrogen peroxide has been demonstrated and some of its decomposition products have been identified (8). The decomposition of hemin and hemoglobin in the presence of unsaturated lipids usually has been investigated under conditions in which the porphyrin compound has served as a catalyst for the oxidation of polyunsaturated fatty acids in an aqueous emulsion (3,9,10). Studies also have been conducted using mixtures of crude peroxides in an aqueous medium. Tappel (10) found that in a colloidal system 300 moles of hydroperoxides were needed to destroy one moIe of hematin at 40°C. Dubouloz (11), using a different set of conditions, obtained a ratio of 50. In the homogenous system used in the present study, the destruction of 1 mole of hemin required only 4 moles of pure hydroperoxide.The destruction of hematin catalysts which occurs during the oxidation of linoleate or during decomposition of linoleate peroxide has been attributed to random reactions between the hematin ...