A new alkaloid and other anti-implantation principles from Tabernaemontana heyneana.

A new alkaloid designated as ervatine, in addition to seven known alkaloids, viz. tabersonine, coronaridine, heyneanine, voacristine, voacristine hydroxyindolenine, hydroxyibogamine, and coronaridine hydroxyindolenine, were isolated from the fruit of Tabernaemontana heyneana Wall. Characterisation and structure elucidation of these compounds was made on the basis of their spectral analyses. The ethanolic extract and isolated alkaloids heyneanine and voacristine prevented pregnancy when administered during the preimplantation period in Sprague-Dawley rats. These were, however, found to possess significant uterotrophic activity.