(-)-BO 2367

(-)-BO 2367, an antimicrobial quinolone, is a strong mammalian and bacterial topoisomerase II inhibitor. (-)-BO 2367 shows IC50 values with 3.8 μM, 0.5 μM, and 1 μM against the DNA relaxation activity of L1210 topoisomerase II and the supercoiling activities of Escherichia coli gyrase and Micrococcus luteus gyrase, respectively. (-)-BO 2367 is a potent antitumor agent.