Electron uptake by classical electron donators: astaxanthin and carotenoid aldehydes

Carotenoids are prime examples for antioxidants: they donate electrons to noxious radicals. Density functional calculations anticipate the possibility of electron uptake by carotenoids. This prediction has been confirmed experimentally: carbonyl carotenoids, including the super-antioxidant astaxanthin, easily take up electrons and react as antireductants.