title: Reduction of oxidized guanosine by dietary carotenoids: a pulse radiolysis study.
abstract: Time-resolved pulse radiolysis investigations reported herein show that the carotenoids β-carotene, lycopene, zeaxanthin and astaxanthin (the last two are xanthophylls--oxygen containing carotenoids) are capable of both reducing oxidized guanosine as well as minimizing its formation. The reaction of the carotenoid with the oxidized guanosine produces the radical cation of the carotenoid. This behavior contrasts with the reactions between the amino acids and dietary carotenoids where the carotenoid radical cations oxidized the amino acids (tryptophan, cysteine and tyrosine) at physiological pH.
authors.affiliation: School of Chemistry, The University of Manchester, Oxford Road, Manchester M13 9PL, UK.
authors.forename: Ruth
authors.initials: R
authors.lastname: Edge
authors.forename: Parimal
authors.initials: P
authors.lastname: Gaikwad
authors.forename: Suppiah
authors.initials: S
authors.lastname: Navaratnam
authors.forename: B S Madhava
authors.initials: BS
authors.lastname: Rao
authors.forename: T
authors.initials: T
authors.lastname: George Truscott
mesh_terms: D002338:Carotenoids / Q000378:metabolism*; D004032:Diet; D004579:Electron Transport; D006151:Guanosine / Q000378:metabolism*; D007700:Kinetics; D009705:Nucleosides / Q000378:metabolism; D011675:Pulse Radiolysis / Q000379:methods*
chemical_list: D009705:Nucleosides; D006151:Guanosine; D002338:Carotenoids