Bioactive indole alkaloids isolated from Alstonia angustifolia

A new sarpagine-type indole alkaloid (1), together with nine known alkaloids (2 – 9), were isolated from the stems of Alstonia angustifolia Wall. ex A. DC. (Apocynaceae) collected in South Vietnam. Compounds 1 – 10 were evaluated for their NF- κ B (p65) inhibitory activities against HT-29 cells in an ELISA assay. The new sarpagine alkaloid (1), was found to show significant NF- κ B inhibitory activity (ED 50 = 1.2 µ M). Furthermore, all the isolates (1 – 10) were tested in vitro for their antileishmanial activity, and compounds (1 – 4, 6, 8 – 10) were found to show leishmaniacidal activities.