Synonyms: Astaxanthin;6-hydroxy-3-[(1E,3E,5E,7Z,9E,11E,13E,15E,17E)-18-(4-hydroxy-2,6,6-trimethyl-3-oxocyclohexen-1-yl)-3,7,12,16-tetramethyloctadeca-1,3,5,7,9,11,13,15,17-nonaenyl]-2,4,4-trimethylcyclohex-2-en-1-one;3,3'-Dihydro-beta,beta-carotene-4,4'-dione;