Aspidospermidine-3-carboxylic acid, 4-(acetyloxy)-6,7-didehydro-15-[(5S,7R,9S)-5-ethyl-1,2,3,4,5,6,7,8,9,10-decahydro-5-hydroxy-9-(methoxycarbonyl)-7-[[[(4-methylphenyl)sulfonyl]oxy]methyl]-3-[(2-nitrophenyl)sulfonyl]azacycloundecino[5,4-b]indol-9-yl]-3-hydroxy-16-methoxy-1-methyl-, methyl ester, (2…