Antiplasmodial activity of bacilosarcin A isolated from the octocoral-associated bacterium Bacillus sp. collected in Panama

AIM: This study was designed for isolating and characterizing antiplasmodial compounds from marine octocoral-associated bacteria. MATERIALS AND METHODS: The organic extract of the Bacillus sp. was subjected to purification using several chromatography techniques guided by bioassays to yield three isocoumarin derivatives (1–3). Chemical structures of the compounds were elucidated on the basis of HRMS spectra and NMR spectroscopy. The antiplasmodial activity of the isolated compounds was evaluated in vitro against the chloroquine-resistant Plasmodium falciparum strain W2. RESULTS: Isolated compounds were identified as bacilosarcin A (1), AI77-F (2), and AI77-H (3). Bacilosarcin A (1) displayed a low micromolar activity (IC(50) = 2.2 μM) against P. falciparum while compounds 2 and 3 showed no activity. CONCLUSIONS: Bacilosarcin A was found to be responsible for the antiplasmodial activity observed in the crude extract obtained from the Bacillus sp.