Chemical and pharmacological studies of two medicinal plants: Tabernaemontana contorta stapf and Tabernaemontana inconspicua stapf (apocynaceae)

Abstract

This work describes the isolation and structure elucidation of secondary metabolites from the fruits and stem-bark of Tabernaemontana contorta and stem Tabernaemontana inconspicua, as well as the evaluation of the anti-inflammatory and cytotoxicity potencies of some isolated compounds. In this study, a total of 28 compounds were isolated using chromatographic techniques and characterized using spectroscopic methods. These compounds were classified as: 9 alkaloids with 3 new derivatives, 8 triterpeniods with 1 new derivative, 1 monoterpene, 7 lipids with 1 new cerebroside and 3 steriods. Two of the new indole alkaloids (apparicine-21-one and 5,6-dioxo-11-methoxyvoacangine) were tested for their anti-inflammatory activity but no significant activity was observed. The anticancer potency of eight of these compounds was carried on human breast cancer cells and 5,6-dioxo-11-hydroxy voacangine showed a significant activity. This compound inhibited the cell growth in both a concentration and time-dependent manner, and it therefore suggests that this compound be used as a chemotherapeutic agent since it was found to be more effective over time exposure.