133541-29-4 5-Carboxytetrahydroalstonine 5-Cehas Methyl 7,8,13,13b,14,14a-hexahydro-4-methyl-5-oxo-4H-indolo-(2,3-a)pyrano(3,4-g)quinolizine-7-carboxylate Oxayohimban-5-carboxylic acid, 16,17-didehydro-19-methyl-21-oxo-, methyl ester, (5beta,19alpha,20alpha)-(+-)-, compd. with 2-propanone (1:1)