Antioxidant reactions of alpha-tocopherolhydroquinone.
Alpha-tocopherolhydroquinone (TQH2) is a product of alpha-tocopherol oxidation/reduction that exerts antioxidant effects in biological systems. TQH2 inhibited autoxidation of methyl linoleate initiated by peroxyl radicals derived from thermolysis of 2,2'-azobis(2,4-dimethylvaleronitrile) in acetonitrile. TQH2 oxidation yielded alpha-tocopherolquinone (TQ) as a major product and 2,3-epoxy-alpha-tocopherolquinone and 5,6-epoxy-alpha-tocopherolquinone as minor products. Each TQH2 consumed approximately two peroxyl radicals in the course of the oxidation. The data suggest that TQH2 scavenges peroxyl radicals primarily by electron transfer to form TQ and secondarily by addition-elimination to form the epoxyquinones.
Liebler
D C
DC
Department of Pharmacology and Toxicology and Southwest Environmental Health Sciences Center, College of Pharmacy, The University of Arizona, Tucson 85721-0207, USA. liebler@pharmacy.arizona.edu
Burr
J A
JA
D000975:Antioxidants / Q000737:chemistry / Q000378:metabolism*; D004852:Epoxy Compounds / Q000378:metabolism; D016166:Free Radical Scavengers / Q000378:metabolism; D006873:Hydroquinones / Q000737:chemistry / Q000378:metabolism*; D007700:Kinetics; D008041:Linoleic Acids / Q000378:metabolism; D015394:Molecular Structure; D010084:Oxidation-Reduction; D010545:Peroxides / Q000378:metabolism; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D024502:alpha-Tocopherol / Q000031:analogs & derivatives*
D000975:Antioxidants; D004852:Epoxy Compounds; D016166:Free Radical Scavengers; D006873:Hydroquinones; D008041:Linoleic Acids; D010545:Peroxides; D014810:Vitamin E; C024838:alpha-tocopherol quinol; C005575:methyl linoleate; C049375:perhydroxyl radical; C002421:tocopherylquinone; D024502:alpha-Tocopherol