ALKALOID STUDIES .61. STRUCTURE OF 12 NEW ALKALOIDS FROM ASPIDOSPERMA CYLINDROCARPON

Twelve new alkaloids have been isolated from Aspidosperma cylindrocarpon; six (IX, X, and XIV-XVII) belong to a new series of aspidospermine-type with 20-hydroxy- and 21-carboxymethyl groups. These compounds differ in the nature of their N-acyl substituents (formyl, acetyl, benzoyl, cinnamoyl, and dihydrocinnamoyl). The demethoxy (VIII). N-formyl (V). N-benzoyl (VI), and N-methyl (VII) analogues of cylindrocarpidine (III) were also found, together with the unsubstituted compound which is now named ' cylindrocarine ' (IV) to facilitate the nomenclature of its derivatives. In addition N-formyl (XIX) and N-acetyl (XX) cylindrocarpinol were characterized.