Figure 4. Determination of MIC (µg/ml) of three Chembridge compounds against M. smegmatis overexpressing Mt-GuaB2, M. smegmatis pVV16 and M. smegmatis mc² 155 to ascertain the mode of action.

M. smegmatis mc² 155 (left plate), M. smegmatis pVV16 (middle plate) and Mt-GuaB2 overexpression construct in pVV16 (right plate) were grown to mid log phase and serial dilutions of cultures (10⁻¹ to 10⁻⁴) were spotted on TSB plates in the absence and presence of different concentrations of compounds 6655281 and 7759844. The plates were incubated at 37°C for 3 days. The minimal concentration of the inhibitor which completely inhibited 99% of M. smegmatis growth was considered as MIC. The MIC results of compound 5217501 are shown in the table below.