(5S)-5-[(4aR,8aS,9E,11S,13R,14S,16R,17R,19S)-11,19-Dihydroxy-8,10,13,16-tetramethyl-18- methylidene-3,4,5,6,8a,11,12,13,14,15,16,17,18,19,20,21-hexadecahydro-2H-14,17- epoxybenzo[2,3]cyclohexadeca[1,2-b]pyridine-7-yl]-3-methylfuran-2(5H)-one (12- Methylgymnodimine B)