Carotenoid esters

Abstract

Monoesters, diesters and polyesters are provided wherein both the acid-derived moiety and the alcohol-derived moiety of the esters are carotenoid compounds. The synthetic ester linkage between two or more carotenoids provides new compounds in which the similar and complementary properties of the individual carotenoids are combined. The new all-carotenoid esters may be useful as antioxidants, therapeutic agents, pigmenting ingredients in poultry feed or as coloring agents for fats. The polyesters have the potential to act as molecular wires with unique electrical conductance characteristics. The all-carotenoid esters may be prepared from the esterification of at least one hydroxy carotenoid with at least one carboxylic carotenoid, or via the reaction of the acid chloride of a carboxylic carotenoid with a hydroxy carotenoid. Preferred hydroxy carotenoids include lutein, zeaxanthin, cryptoxanthin, violaxanthin, carotene diol, hydroxy carotene, hydroxylycopene, alloxanthin and dehydrocryptoxanthin. Preferred carboxylic carotenoids include bixin, norbixin, &bgr;-apo-8-carotenoic acid, crocetin, diapocarotenoic acid, carboxylcarotene and azafrin.