Antibacterial activity of two limonoids from Swietenia mahagoni against multiple-drug-resistant (MDR) bacterial strains.

Solvent partitioning followed by column chromatography of the MeOH extract of the seeds of Swietenia mahagoni afforded two limonoids, swietenolide (1) and 2-hydroxy-3-O-tigloylswietenolide (2). The compounds were identified by spectroscopic means. The antibacterial activity of these compounds was assessed against eight multiple-drug-resistant bacterial strains (clinical isolates) by the conventional disc diffusion method. While both compounds were active against all test organisms, compound 2 displayed overall more potent activity than compound 1.