The Constituents of Naucleadiderrichii. Part II. Isolation and Classification of Constituents; Simple β-Carboline and Pyridine Alkaloids

Abstract

The bark of Naucleadiderrichii (Rubiaceae) has afforded a considerable number of constituents, mainly alkaloids. For convenience these have been placed in four categories: (1) simple β-carbolines, (2) simple pyridines, (3) indole-pyridines, and (4) miscellaneous substances. Isolation procedures and the elucidation of the structures of constituents in categories (1) and (2) are described in this paper. Spectroscopic evidence supported by synthesis has been used to assign structures 1, 2, 3, and 4 to the four simple β-carbolines and structures 5, 6, 7, and 8 to the four simple pyridines isolated.