Definition of carotenoids

1. Tetraterpenoids (C40), formally derived from the acyclic parent ,-carotene (I) by hydrogenation, dehydrogenation, cyclization, oxidation, or combination of these processes. This class includes carotenes, xanthophylls and certain compounds that arise from rearrangement of the skeleton of (I) or by loss of part of this structure. Retinoids are excluded. BNRD Rule Carotenoid-1 (p. 226, 237). See also retro. E.g.