Table 2.

Inhibitory activity of type II compounds 22a-d and 23a-d against DNA gyrase from E. coli.

Compd.	R1	R2	R3	IC50 (nM)a or RA (%)b
				E. coli gyrase
22a	4,5-diBr	Bn	Me	100%
22b	4,5-diBr	CH2CH2N(Me)2	Me	88%
22c	4,5-diBr	iPr	Me	91%
22d	3,4-diCl-5-Me	iPr	Me	59%
23a	4,5-diBr	Bn	H	88 ± 0 nM
23b	4,5-diBr	${\text{CH}}_2{\text{CH}}_2\text{NH}{(\text{Me})}_2^{+}{\text{CI}}^{-}$	H	82%
23c	4,5-diBr	iPr	H	400 ± 90 nM
23d	3,4-diCl-5-Me	iPr	H	91 ± 29 nM
novobiocin				170 ± 20 nM

^aConcentration of compound that inhibits the enzyme activity by 50%.

^bResidual activity of the enzyme at 1 μM of the compound.