15H-Pyrrolo[2,1-f][1,15,4,7,10,20] dioxatetraazacyclotricosine-1,4,8,13,16,18,21-heptaone, docosahydro-11-hydroxy-3-[(4-methoxyphenyl)methyl]- 2,6,17-trimethyl-15-(methylethyl)-10-(1-methylpropyl)- 20-(2-methylpropyl)-7-[[N-methyl-N-prolylleucyl]amino]-,stereoisomer Didemnin A, N-L-prolyl-2-L-allothreonine L-Tyrosine, N-[1-[N-[4-[[3-hydroxy-6-methyl-4-[[N- (N-methyl-N-L-prolyl-L-leucyl)-L-threonyl]amino]- 1-oxoheptyl]oxy]-2,5-dimethyl-1,3-dioxohexyl]-L-leucyl]-L-prolyl]-N,O-dimethyl-, .phi.-lactone NSC665803