FIG 1.

CB37 and CB81 are 4-amino-thieno[2,3-d]pyrimidines that inhibit the growth of M. smegmatis. (A) Structure of CB37. (B) M. smegmatis (Msm) strain csm208 (Table 2) was incubated in LB medium in the presence of DMSO, 100 μM CB37, or 73 μM rifampin (Rif), and the optical density at 600 nm (ODλ₆₀₀) was measured periodically over the course of 12 h in a plate reader (n = 2 replicates). (C) Structure of CB81, which was resynthesized and renamed CWHM-728. (D) M. smegmatis strain csm208 was incubated in LB medium in the presence of DMSO, 100 μM CB81, or 73 μM rifampin, and the ODλ₆₀₀ was measured over the course of 12 h in a plate reader (n = 3 replicates).