Photo-oxidation of chlorophyll A in digalactosyldiacylglycerol liposomes containing xanthophyll pigments: indication of a special photoprotective ability of zeaxanthin

Photoprotective efficiency of lutein, zeaxanthin and violaxanthin in liposomes made of digalactosyldiacylglycerol (DGDG) has been investigated. It was found that zeaxanthin is about ten times more effective than the two other xanthophylls in inhibition of chlorophyll a photo-oxidation. Kinetics of chlorophyll photobleaching suggests that exceptional photoprotective efficacy of zeaxanthin in membranes consists in effective scavenging of free radicals. High photoprotective efficiency of zeaxanthin in membranes correlates with its physiological function.