Table 2.

Cytotoxicity profile of compounds 13–16 and selectivity against the murine macrophage cell line RAW 264.7 using the resazurin assay.

Compound	MIC[a]M. tb H37Rv µM (mg L−1)	GIC [b]µM (mg L−1)	SI[c]
13	225 (64)	439 (125)	1.95
14	17 (4)	272 (62.5)	16
15	138 (32)	135 (31.3)	0.98
16	167 (32)	40 (7.8)	0.24
INH	0.7 (0.1)	No inhibition	*

INH was used as a control drug and shows no effect on the viability of the cells. A drop in the fluorescence levels indicate loss of viability of cells as determined by the reduction in the oxidation of resazurin to resorufin which in turn fluoresces. The experiments were performed in triplicate. ^[a]MIC - minimum inhibitory concentration.

^[b]GIC - growth inhibitory concentration.

^[c]SI - selectivity index, where SI = GIC/MIC (SI calculated using the µM values in Table 2).

^[d]INH- Isoniazid (control, front-line anti-tubercular drug)*. As no significant inhibition is observed the SI in these cases cannot be calculated.