Two antimicrobial alkaloids from Bocconia arborea.

Two alkaloid constituents of Bocconia arborea showed considerable antimicrobial activity against gram-positive and gram-negative bacteria and Candida albicans. Bioactivity-guided fractionation with thin-layer bioautography led to the isolation of the two known benzophenanthridine alkaloids, dihydrochelerythrine and dihydrosanguinarine. The minimal inhibitory concentration was determined for each compound using a twofold serial dilution assay. The structures of these compounds were determined by 1H and 13C NMR analyses.