has role has parent hydride independent continuant beta-carotene antioxidant carotenol carotenone astaxanthin A carotenone that consists of β,β-carotene-4,4'-dione bearing two hydroxy substituents at positions 3 and 3' (the 3<i>S</i>,3'<i>S</i> 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. CHEBI:40968 anticoagulant anti-inflammatory agent animal metabolite plant metabolite food colouring