Aspidospermidine-3-carboxylic acid, 2,3-didehydro-15-((16S)-1,13-didehydro-10,13-dihydro-17-methoxy-10,17-dioxo-2,4(1H)-cyclo-3,4-secoakuammilan-11-yl)-16-methoxy-1-methyl-, methyl ester, (5alpha,12beta,19alpha)-