Indole alkaloids from Ervatamia orientalis. I. Isolation of alkaloids and structural identification of two dimers

Abstract

Ethanol extracts of Ervatamia orientalis have yielded the following known alkaloids: ibogaine, iboxygaine, voacristine, vobasine, dregamine, tabernaemontanine, apparicine, voacamine and 16- demethoxycarbonylvoacamine. In addition, two new dimeric alkaloids of the voacamine group and the novel 2-acylindoles ervatamine, 20- epiervatamine and 19-dehydroervatamine have been isolated from the extracts. The two new dimeric compounds have been identified by physical and chemical methods as 16-demethoxycarbonyldihydrovoacamine and 16-demethoxycarbonyl-20?-epi-dihydrovoacamine.