2,2'-Dinor-beta,beta-carotene-3,4,3',4'-tetraone 22453-06-1 28275-20-9 4,4'-(3,7,12,16-Tetramethyl-1,3,5,7,9,11,13,15,17- octadecanonaene-1,18-diyl)bis(3,5,5-trimethyl-3- cyclopentene-1,2-dione) Violerythrin