Studies of carotenoid one-electron reduction radicals,

Abstract:The relative reduction potentials of a variety of carotenoids have been established by monitoring the reaction of carotenoid radical anion (CAR1^•-) with another carotenoid (CAR2) in hexane and benzene. This order is consistent with the reactivities of the carotenoid radical anions with porphyrins and oxygen in hexane. In addition, investigation of the reactions of carotenoids with reducing radicals in aqueous 2% Triton-X 100, such as carbon dioxide radical anion (CO₂^•-), acetone ketyl radical (AC^•-) and the corresponding neutral 2 radical (ACH^•), reveals that the reduction potentials for b-carotene and zeaxanthin lie in the range