Antiplasmodial and anti-trypanosomial monoterpene indole alkaloids from Picralima nitida.

Eight monoterpene indole alkaloids (1-8), including one new picraline-type alkaloid, 2-hydroxyakuammiline (4) and seven known compounds: akuammigine (1), akuammine (2), akuammidine (3), akuammiline (5a), akuammiline N-oxide (5b), akuammiline (6), rhazimol (7), and alstonine (8) were isolated from the seeds of Picralima nitida. Structure elucidation was done by analysis of their MS and NMR spectroscopic data. The antiplasmodial effects of compounds 1-7 were moderate. Compound 8 showed significant effects with pXC50 of 6.3. Compounds 1 and 7 showed significant trypanocidal effects with pXC50's of 5.1 and 5.4 respectively.