Studies on the pharmacology of conopharyngine, an indole alkaloid of the voacanga series.

Conopharyngine, the major alkaloid present in the leaves of Tabernaemontana (Conopharyngia) pachysiphon var. cumminsi (Stapf) H. Huber was isolated and identified by Thomas & Starmer (1963). The same alkaloid has also been found in the stem bark of a Nigerian variety of the same species by Patel & Poisson (1966) and in the stem bark of Conopharyngia durissima by Renner, Prins & Stoll (1959). Conopharyngine is an indole alkaloid of the voacanga type, being 18-carbomethoxy-12,13dimethoxyibogamine (Fig. 1) and is thus closely related to voacangine and coronaridine.