Premium
One‐electron reduction potentials of dietary carotenoid radical cations in aqueous micellar environments
Author(s) -
Burke Marc,
Edge Ruth,
Land Edward J.,
McGarvey David J.,
Truscott T.George
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02601-1
Subject(s) - chemistry , carotenoid , radiolysis , radical , astaxanthin , radical ion , photochemistry , canthaxanthin , aqueous solution , solvated electron , electron transfer , organic chemistry , ion , biochemistry
The one‐electron reduction potentials of the radical cations of five dietary carotenoids (β‐carotene, canthaxanthin, zeaxanthin, astaxanthin and lycopene) in aqueous micellar environments have been obtained from a pulse radiolysis study of electron transfer between the carotenoids and tryptophan radical cations as a function of pH, and lie in the range of 980–1060 mV. These values are consistent with our observation that the carotenoid radical cations oxidise tyrosine and cysteine. The decays of the carotenoid radical cations in the absence of added reactants suggest a distribution of exponential lifetimes. The radicals persist for up to about 1 s, depending on the medium.