Scavenging of benzylperoxyl radicals by carotenoids.
Carotenoids scavenge simple lipid-like alkylperoxyl radicals. However, the rate constant is too low to be determined directly and the mechanism is likewise not known with certainty [Mortensen, A. and Skibsted, L.H. (1998) FEBS Lett. 426, 392-396]. It is demonstrated that carotenoids react with peroxyl radicals only slightly more reactive than lipidperoxyl radicals neither by electron transfer nor by hydrogen atom donation, but by adduct formation. Benzylperoxyl radicals are scavenged by the carotenoids beta-carotene and canthaxanthin with a second-order rate constant of at least 1 x 10(6) M(-1) s(-1) by formation of an adduct which decays in a first-order reaction.
Mortensen
Alan
A
Department of Dairy and Food Science, Royal Veterinary and Agricultural University, Frederiksberg C, Denmark. alan.mortensen@dk.chr-hansen.com
D001585:Benzoyl Peroxide / Q000737:chemistry* / Q000378:metabolism; D002338:Carotenoids / Q000737:chemistry* / Q000378:metabolism; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D007834:Lasers; D010084:Oxidation-Reduction; D010782:Photolysis; D013056:Spectrophotometry, Ultraviolet
D016166:Free Radical Scavengers; D002338:Carotenoids; D001585:Benzoyl Peroxide