Studies of the reactivity of trolox with Mn3+/Fe3+ complexes by pulse radiolysis

The rates and mechanisms for the reactions between Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), a synthetic analogue of alpha-tocopherol, Br2- and Mn3+-phosphate were determined under aerobic and anaerobic conditions by fast kinetic methods. In addition, the reaction between Fe(OH)2+ and Trolox at pH 6.0 was shown not to occur under the conditions of the experiment, leading to a limiting rate for that reaction of k less than 10(3) M-1 s-1. These results are compared to studies of the reactivity of Trolox with HO2/O2- and are discussed in light of the known antioxidant properties of vitamin E.