In vitro antimicrobial activity of benzoquinolinediones.

The in vitro antibacterial and anti-fungal activity of benz[g]isoquinoline-5,10-dione (1), benzo[g]quinoline-5, 10-dione (2), benzo[g]quinoline-5,6-dione (3), and anthraquinone (4) was determined using the agar well-diffusion assay. The minimum inhibitory concentrations (MIC's) of each of the active compounds (1-3) was determined using the two-fold serial dilution technique. Of the four compounds tested, benz[g]isoquinoline-5,10-dione exhibited the best overall activity against both bacteria and fungi. Particularly noteworthy was its significant antifungal activity which was comparable to the activity of the standard antifungal antibiotic amphotericin B.