Lutein quench singlet oxygen

Some carotenoids are precursors (provitamins) of vitamin A. Other carotenoids, such as cryptoxanthin, zeaxanthin and lutein, exhibit, by contrast, about half of the activity of provitamins A. Some carotenoids, such as lycopene, astaxanthin and canthaxanthin, are more effective in quenching singlet oxygen than P-carotene. Carotenoids also react with free radicals such as P-carotene. Because of their antioxidative properties, they are used in the prevention of degenerative processes and as anticancer agents. 

The observation that lutein in the retina is converted to (meso)-zeaxanthin appears to be physiologically plausible due to the presence of, in comparison to lutein, one additional conjugated double bond, it has a stronger singlet oxygen quenching capability (Cantrell et al. 2003). Furthermore, it has been reported that (meso)-zeaxanthin provides a somewhat better protection against the oxidation... 

Metal chelation Oxygen scavenging and reducing agents Singlet oxygen quenching Cirtic, Malic, Succinic and Tartaric acids Ethylenediaminetetraacetic acid, Phosphates Ascorbic acid, Ascorbyl palmitate, Erythorbic acid. Sodium erythorbate. Sulfites Carotenoids (p-Carotene, Lycopene and Lutein)... 

Carotenoids Alpha- and beta-carotene cryptoxanthin, lutein, lycopene, zeaxanthin Quench singlet and triplet oxygen, increase cell-cell communication Red, orange and yellow fruits and vegetables, egg yolk, butter fat, margarine... 

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