Antiplasmodial and anti-trypanosomial monoterpene indole alkaloids from <i>Picralima nitida</i>

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