A carotenone that consists of beta,beta-carotene-4,4'-dione bearing two hydroxy substituents at positions 3 and 3' (the 3S,3'S diastereomer). A carotenoid pigment found mainly in animals (crustaceans, echinoderms) but also occurring in plants. It can occur free (as a red pigment), as an ester, or as a blue, brown or green chromoprotein.
Belongs to the class of organic compounds known as xanthophylls. These are carotenoids containing an oxygenated carotene backbone. Carotenes are characterized by the presence of two end-groups (mostly cyclohexene rings, but also cyclopentene rings or acyclic groups) linked by a long branched alkyl chain. Carotenes belonging form a subgroup of the carotenoids family. Xanthophylls arise by oxygenation of the carotene backbone.
