Definitions
1.NounA carotenoid (1R,2R)-4-[(1E,3E,5E,7E,9E,11E,13E,15E,17E)-18-[(4R,5R)-4,5-dihydroxy-2,6,6-trimethylcyclohexen-1-yl]-3,7,12,16-tetramethyloctadeca-1,3,5,7,9,11,13,15,17-nonaenyl]-3,3,5-trimethylcyclohex-4-ene-1,2-diol present in some bacteria and blue-green algae