trilobolide

(Z)-2-Methyl-2-butenoic acid (3S)-6α-acetoxy-2,3,3a,4,5,6,6aα,7,8,9bβ-decahydro-3,3aα-dihydroxy-3,6β,9-trimethyl-4β-[(S)-2-methyl-1-oxobutoxy]-2-oxoazuleno[4,5-b]furan-8β-yl ester