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Reactions of biological antioxidants: I. Fe(III)‐catalyzed reactions of lipid hydroperoxides with α‐tocopherol
Author(s) -
Gruger E. H.,
Tappel A. L.
Publication year - 1970
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02531464
Subject(s) - chemistry , degree of unsaturation , tocopherol , catalysis , polyunsaturated fatty acid , linolenate , organic chemistry , methyl oleate , autoxidation , lipid oxidation , antioxidant , menhaden , kinetics , phospholipid , lipidology , medicinal chemistry , fatty acid , biochemistry , vitamin e , fish oil , physics , quantum mechanics , fishery , fish <actinopterygii> , biology , membrane
Rates of α‐tocopherol oxidation were measured for free‐radical reactions produced by Fe(III)‐catalyzed dissociations of hydroperoxides. The kinetics were treated as first‐order in α‐tocopherol. The hydroperoxides were preformed from methyl linoleate, methyl linolenate, ethyl arachidonate, methyl eicosapentaenoate, and a fraction of polyunsaturated fatty esters of menhaden oil. The degree of unsaturation of the lipid hydroperoxides had little effect on the rates of α‐tocopherol oxidation. The rates of oxidation decrease with the concentration of water and increase with the acidity of the media. The pH data suggest a transition from one predominant mechanism to another, which may involve principally acid catalysis. A mechanism for α‐tocopherol oxidation is suggested.