Carotene-Oxygen Radical Interactions

Abstract
All-trans β-carotene radical anion efficiently transfers an electron to oxygen but the reverse reaction is not observed and, instead we suggest the formation of a β-carotene-superoxide radical addition complex. On the other hand, all-trans lycopene undergoes a reversible electron transfer with the superoxide radical. This distinctive behaviour may be related to the anti-cancer properties of these molecules.