Table 3.

E. coli DNA gyrase and topoisomerase IV inhibitory activities of compounds 2–6 and Novobiocin.

Compound	IC50 (nM) a or RA (%) b	IC50 (µM) a or RA (%) b
	E. coli DNA Gyrase	E. coli Topo IV
2	57%	89%
3	86 ± 9 nM	58%
4	42 ± 7 nM	1.47 ± 0.20 µM
5	92 ± 9 nM	6.80 ± 0.20 µM
6	180 ± 20 nM	8.92 ± 0.20 µM
Novobiocin	170 ± 20 nM	11 ± 2 µM

^a Concentration of compound that inhibits the enzyme activity by 50%; ^b residual activity of the enzyme at 1 µM of the compound.