9,12-Epoxy-1H-diindolo(1,2,3-fg:3',2',1'-kl)pyrrolo(3,4-i)(1,6)benzodiazocine-10-carboxylic acid, 2,3,9,10,11,12-hexahydro-10-hydroxy-9-methyl-1-oxo-16-propoxy-, methyl ester, (9alpha,10beta,12alpha)-