Table 2. In Vitro Antitubercular Activity of Compounds 6a–6d, 6h–6j, and 6l against the Mtb Strains H37Rv, rRMP, and rINH with the Assay Concentrations Ranging from 0.002 to 0.5 μg/mL, and Vero Cellular Toxicity.

	MIC (μg/mL)
compds	H37Rv	rRMP	rINH	VERO cell IC50 (μg/mL)	selectivity index (SI)a
6a	0.013	<0.002	<0.002	3.15	242
6b	0.007	<0.002	0.003	11.8	1685
6c	0.029	<0.002	0.003	11.6	402
6d	<0.002	<0.002	0.004	>50	>25000
6h	0.007	<0.002	0.004	>50	>7142
6i	0.053	0.458	0.004	28.4	535
6j	<0.002	<0.002	0.002	>50	>25000
6l	<0.002	0.465	0.002	>50	>25000
RMP	<0.008	>2	<0.008	>100	>12500
INH	0.239	0.438	>8
LIZ	1.254	1.870	0.953
TMC207	0.020	<0.016	<0.016	>10	>500

^aSI: IC₅₀/MIC for H37Rv.