Table 11. Achillion isothiazoloquinolone SAR for MRSA (MIC) and cytotoxicity in Hep2 cells (CC₅₀). Ciprofloxacin 15, moxifloxacin, and gemifloxacin 102 serve as reference compounds.

Compound	R6	R7	X	MRSAa MIC (µg/ml)	Hep2 cellsb CC50 (µg/ml)c [topo II EC2 (µg/ml)]c,d
91	F		CH	2	3
92	F		COCH3	0.5	8 [32]
93	H		COCH3	2	40
94	F		CH	1	1
95	F		COCH3	0.5	6 [15]
96	H		COCH3	2	19
97	F		COCH3	2	10
98	F		COCH3	0.25	4
99	F		COCH3	4	>43
100 ACH702	F		COCH3	0.06	4
101	F		COCH3	2	28
15 ciprofloxacin	F		CH	32	>33 [>50]
12 moxifloxacin	F		COCH3	2	>40 [>60]