title: Lycopene is more potent than beta carotene in the neutralization of singlet oxygen: role of energy transfer probed by ultrafast Raman spectroscopy.
abstract: Energy transfer processes between beta carotene, lycopene, and singlet oxygen ((1)O(2)) have been studied by ultrafast Raman spectroscopy. Our experimental results demonstrate that during the neutralization of singlet oxygen by beta carotene the excitation energy of singlet oxygen is transferred directly to the first excited electronic state S(1) of beta carotene. In contrast, the excitation energy of singlet oxygen is transferred directly to the ground excited vibronic state S(0) of lycopene. Our data not only provide the first direct experimental elucidation of energy transfer processes in such important biological systems but also help explain why lycopene is a more potent antioxidant than beta carotene in the neutralization of singlet oxygen.
authors.affiliation: Arizona State University, Department of Physics and Astronomy, Tempe, Arizona 85287-1504, USA. tsem@asu.edu
authors.forename: Kong-Thon
authors.initials: KT
authors.lastname: Tsen
authors.forename: Shaw-Wei D
authors.initials: SW
authors.lastname: Tsen
authors.forename: Juliann G
authors.initials: JG
authors.lastname: Kiang
mesh_terms: D002338:Carotenoids / Q000737:chemistry*; D004735:Energy Transfer; D000077276:Lycopene; D026082:Singlet Oxygen / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D019207:beta Carotene / Q000737:chemistry*
chemical_list: D019207:beta Carotene; D026082:Singlet Oxygen; D002338:Carotenoids; D000077276:Lycopene