title: Inhibition of lipid peroxidation by alpha-tocopherolquinone and alpha-tocopherolhydroquinone.
abstract: The antioxidant effect of alpha-tocopherolquinone and alpha-tocopherolhydroquinone was studied in liposomes and rat liver submitochondrial particles. Both alpha-tocopherolquinone and alpha-tocopherolhydroquinone inhibit lipid peroxidation induced by ascorbate/Fe2+ in liposomes and by cumene hydroperoxide in submitochondrial particles. Alpha-tocopherolhydroquinone is much more effective than alpha-tocopherolquinone in inhibiting lipid peroxidation. Submitochondrial particles, depleted of ubiquinones and reincorporated with alpha-tocopherolquinone, are protected from lipid peroxidation only in the presence of succinate. Alpha-tocopherolquinone cannot replace endogenous ubiquinones in the respiratory chain function, nevertheless it can be reduced by the mitochondrial respiratory chain substrates, presumably through the reduced ubiquinones.
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology; D001555:Benzene Derivatives / Q000494:pharmacology; D002417:Cattle; D004579:Electron Transport; D005296:Ferrous Compounds / Q000494:pharmacology; D008054:Lipid Peroxides / Q000378:metabolism*; D008081:Liposomes / Q000378:metabolism*; D008315:Malondialdehyde / Q000378:metabolism; D008930:Mitochondria, Liver / Q000378:metabolism*; D010084:Oxidation-Reduction; D051381:Rats; D013367:Submitochondrial Particles / Q000187:drug effects / Q000378:metabolism*; D013386:Succinates / Q000494:pharmacology; D019802:Succinic Acid; D014451:Ubiquinone / Q000378:metabolism; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000494:pharmacology; D024502:alpha-Tocopherol / Q000031:analogs & derivatives*
chemical_list: D001555:Benzene Derivatives; D005296:Ferrous Compounds; D008054:Lipid Peroxides; D008081:Liposomes; D013386:Succinates; D014451:Ubiquinone; D014810:Vitamin E; C024838:alpha-tocopherol quinol; D008315:Malondialdehyde; C002421:tocopherylquinone; D019802:Succinic Acid; D024502:alpha-Tocopherol; C007164:cumene hydroperoxide; D001205:Ascorbic Acid