Studies of carotenoid one-electron reduction radicals.
Arch Biochem Biophys
; 458(2): 104-10, 2007 Feb 15.
Article
en En
| MEDLINE
| ID: mdl-17188230
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 radical (ACH(*)), reveals that the reduction potentials for beta-carotene and zeaxanthin lie in the range -1950 to -2100 mV and those for astaxanthin, canthaxanthin and beta-apo-8'-carotenal are more positive than -1450 mV. This illustrates that the presence of a carbonyl group causes the reducing ability to decrease. The radical cations have been previously shown to be strong oxidising agents and we now show that the radical anions are very strong reducing agents.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Carotenoides
Idioma:
En
Revista:
Arch Biochem Biophys
Año:
2007
Tipo del documento:
Article
País de afiliación:
Reino Unido