title: Real time detection of reactions between radicals of lycopene and tocopherol homologues.
abstract: Laser flash photolysis of lycopene in homogeneous chloroform solution together with tocopherol homologues results in rapid formation of the lycopene radical cation and slower formation of tocopheroxyl radicals. Time-resolved detection by absorption spectroscopy of decay of the lycopene radical cation, of formation of the tocopheroxyl radicals, and of bleaching of lycopene has shown that alpha-tocopherol is able to reduce the lycopene radical cation and thereby partially regenerate lycopene on a ms timescale. In contrast, lycopene is able to reduce the delta-tocopheroxyl radical, whereas an equilibrium exists between the lycopene radical cation and beta- or gamma-tocopherol. The relative stability of these antioxidant radicals is hence: alpha-tocopheroxyl > lycopene radical cation approximately beta-tocopheroxyl approximately gamma-tocopheroxyl > delta-tocopheroxyl.
authors.affiliation: Department of Dairy and Food Science, Royal Veterinary and Agricultural University, Frederiksberg, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Mortensen
authors.forename: L H
authors.initials: LH
authors.lastname: Skibsted
mesh_terms: D002338:Carotenoids / Q000031:analogs & derivatives* / Q000737:chemistry*; D002725:Chloroform; D005609:Free Radicals; D007700:Kinetics; D000077276:Lycopene; D015394:Molecular Structure; D010782:Photolysis; D013997:Time Factors; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000737:chemistry*
chemical_list: D005609:Free Radicals; D014810:Vitamin E; D002338:Carotenoids; D002725:Chloroform; D000077276:Lycopene