New monoterpenoid indole alkaloids from Tabernaemontana bovina

Abstract Two new monoterpenoid indole alkaloids, taberibogines A and B (1 and 2), together with four known ones (3–6), were isolated from the stems of Tabernaemontana bovina. The structures of these compounds were elucidated using comprehensive spectroscopic analysis and quantum chemistry computational methods. Compounds 1–2 were evaluated for their inhibitory effects on LPS-induced NO production in RAW 264.7 macrophages.