The reactivity of phenoxyl radicals of bioantioxidants in the abstraction reactions

The enthalpies, activation energies, and rate constants for the reactions of 15 phenoxyl radicals derived from natural bioantioxidants with hydroperoxides, C-H bonds of linoleic acid, SH-groups of l-cysteine, and O-H bonds of α-tocopherol (60 reactions) were calculated. The activation energies were calculated using the model of intersecting parabolas. The interatomic distances in the reaction sites of the transition states of the studied reactions were calculated. The factors affecting the reactivity of these radicals are discussed. The activation energy of the reaction of oxygen with the O-H bond of the 1,2-dihydroxybenezene semiquinone radical was estimated.