Effects of Metal Ions and Radical Scavengers on the Peroxidation of Linoleic Acid Catalyzed by L-Ascorbic Acid and Dehydro-L-Ascorbic Acid

摘要

L-Ascorbic acid (AsA) and dehydro-L-ascorbic acid (DHA) were studied for their effects on the peroxidation of linoleic acid (LA) in neutral buffer solution (pH 7) containing alcohol. Ferrous sulfate accelerated the peroxidation of LA catalyzed by both AsA and DHA, but copper ions suppressed the LA peroxidation more or less at any concentration tested, except for the case of 1 μM CuSO_4, 135 μM DHA, 10mM LA, and 20%EtOH in 80mM phosphate buffer. Addition of chelating agents (EDTA and DTPA) to the reaction mixture containing 10% or 20% EtOH suppressed the LA peroxidation very clearly, except for the case of 1 μM EDTA in the reaction mixture containing 180 μM AsA and 10% EtOH. Active oxygen scavenging agents, such as catalase (H_2O_2) and sodium formate (OH) did not prevent LA peroxidation. Therefore, these scavengers do not act directly on the LA peroxidation.