Monoterpenoid indole alkaloids from the stem barks of Voacanga africana and their chemotaxonomic significance.

The phytochemical investigation of the stem barks of Voacanga africana resulted in the isolation of fifteen known monoterpenoid indole alkaloids (1 – 15). The structures of the alkaloids were determined by comparison of their physical and spectroscopic data with those reported in literature. Twelve of these metabolites (4 – 15) were previously unreported within the genus Voacanga , thus they can serve as chemotaxonomic markers for V. africana to differentiate between V. africana from other species of the genus Voacanga. The alkaloids 3-oxoconopharyngine (6), ervahainanmine (10), crassanine (14) and conolobine A (15) hold the potential to serve as chemical markers for distinguishing V. africana from other family species. Furthermore, compounds 3 , 6 , 10 , 12 showed potential antimicrobial activities against Candida albicans and Bacillus subtilis with MIC values of 6.25–12.50 μg/mL. [Display omitted] • A phytochemical investigation of Voacanga africana has been carried out. • Fifteen monoterpenoid indole alkaloids were identified from the stem barks of Voacanga africana. • Twelve compounds 4 – 15 were reported for the first time from the genus Voacanga. • Chemotaxonomic significance of these alkaloids was discussed. • Compounds 3 , 6 , 10 , 12 showed potential antimicrobial activities against Candida albicans and Bacillus subtilis. [ABSTRACT FROM AUTHOR]