Table 3. Comparison of On-Target and Antibacterial Activities of Compounds 1 and 27^a.

enzyme	Cpd. 1 IC50 [nM]	Cpd. 27 IC50 [nM]
E. coli gyrase	<10	<10
E. coli topo IV	350	320
A. baumannii gyrase	<10	16
A. baumannii topo IV	64	6.7
P. aeruginosa gyrase	<10	<10
P. aeruginosa topo IV	235	29
human topoisomerase IIα	1950	25,000

pathogen, strain ID (phenotype)	Cpd. 1 MIC [μg/mL]	Cpd. 27 MIC [μg/mL]
E. coli, ATTC25922 (WT)	4	1
E. coli, CH3130 (efflux-def.)	<0.125	<0.125
K. pneumoniae, ATCC13883 (WT)	2	1
K. pneumoniae, 1161486a (efflux-def.)	n.d.	n.d.
P. aeruginosa, PAO1 (WT)	8	1
P. aeruginosa, PAO750 (efflux-def.)	<0.125	<0.125
A. baumannii, ATCC19606 (WT)	0.5	0.5
A. baumannii, BM4454 (clinical MDR)	<0.125	0.5
A. baumannii, BM4652 (efflux-def.)	<0.5	0.5

^an.d., not determined; WT, wild type; MDR, multidrug-resistant.