Monoterpenoid indole alkaloids from the leaves of Alstonia scholaris and their NF-κB inhibitory activity.

Four new monoterpenoid indole alkaloids (MIAs), scholarisines P-S (1–4), and 14 known MIAs (5–18) were isolated from the leaves of Alstonia scholaris (L) R. Br. (Apocynaceae). Their structures were elucidated by analyzing their HRESIMS data and NMR spectroscopic data. All of the isolated MIAs were evaluated for their Nuclear Factor-kappa B (NF-κB) inhibitory activity in HepG2-NF-κB-Luc cells. Among them, five compounds (4, 7, 8, 13 and 16) exhibited significant NF-κB inhibitory activity.