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Updated: Aug 18, 2026

Exploring the Radical Nature of a Carbon Surface by Electron Paramagnetic Resonance and a Calibrated Gas Flow
Published on: April 24, 2014
Interaction of oxygen and oxy-radicals with carotenoids
Abstract:
Dye-sensitized photo-oxidations of liposomes are inhibited by the presence of carotenoids in the membrane. Some carotenoid bleaching occurs during the reaction. It was shown that carotenoids are capable of inhibiting free-radical-induced lipid peroxidation in liposomes as well as singlet oxygen-induced lipid peroxidation. There is little direct effect of lipid peroxides on carotenoid bleaching during the photo-oxidative reactions. The carotenoid bleaching observed during the dye-photosensitized oxidations of the liposomes appears to be due to interactions between the carotenoid pigments and either radical intermediates from type I reactions or direct chemical reaction with singlet oxygen in a type II reaction. It was concluded that carotenoid pigments function as protective agents by quenching triplet sensitizers, singlet oxygen, and radical intermediates.
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