The isolated alkaloids from Argemone mexicana seed showed considerable antibacterial activity against pathogenic bacteria, out of which one of them namely Staphylococcus aureus is Gram positive and remaining three Gram negative namely, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. Fractionation followed by TLC leds to the isolation of two known benzophenanthridine alkaloids namely and dihydroxysanguinarine and dimethylsanguinarine. The MIC was determined for each compound using a two fold serial dilution assay. The structures of these compounds are determined by 1H1 and 13C NMR analysis.

Keywords: Argemone mexicana; Alkaloids; Antibacterial activity