The short-chain homologue of dihydrolipoic acid, tetranordihydrolipoate, protects against iron-induced lipid peroxidation in the aqueous phase.
Because iron is involved in catalysis of many biological oxidations, it is important to investigate new and novel antioxidants in terms of their effect on iron-catalyzed oxidations. We investigated the effect of dihydrolipoic acid (6,8-dimercaptooctanoic acid (DHLA)), its homologues (4,6-dimercaptohexanoic acid (bisnorDHLA) and 2,4-dimercaptobutanoic acid (tetranorDHLA)) and methyl 6,8-dimercaptooctanoate (methylDHLA) on Fe(II)-citrate-catalyzed lipid peroxide-dependent lipid peroxidation in lipid-dispersed and liposome systems. In the lipid-dispersed system, tetranorDHLA inhibited conjugated diene formation induced by Fe(II)-citrate. In the presence of tetranorDHLA, oxygen was consumed more rapidly in the reaction mixture than in the presence of the other compounds, but the oxidation rate of Fe(II)-citrate in the reaction mixture was slower than in the presence of the other compounds. This suggests that tetranorDHLA inhibited lipid peroxidation by the oxidation of tetranorDHLA itself at the site where the lipid was oxidized.
Kawabata
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T
Department of Molecular and Cell Biology, University of California, Berkeley 94720.
Yap
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SC
Packer
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D066298:In Vitro Techniques; D007501:Iron / Q000737:chemistry*; D008054:Lipid Peroxides / Q000378:metabolism*; D008081:Liposomes; D008956:Models, Chemical; D010084:Oxidation-Reduction; D010101:Oxygen Consumption; D008063:Thioctic Acid / Q000031:analogs & derivatives* / Q000737:chemistry
D008054:Lipid Peroxides; D008081:Liposomes; D008063:Thioctic Acid; C015144:dihydrolipoic acid; D007501:Iron