SFC inactivates B1 MBLs. (A) Summary plot of all 22,671 compounds; values are demonstrated as residual ratios. The dashed line indicates a temporary cutoff value (residual ratio, 0.6) for initial selection of an effective IMP-1 enzyme inhibitor. (B) Representative results of the susceptibility test for IMP-1-producing E. coli cells (E. coli DH5α/pBC-IMP-1). The MIC value of MPM was determined in the presence of 10 μg/ml of the tested compounds. The chemical structure of the 243-G03 compound, 2,5-dimethyl-4-sulfamoylfuran-3-carboxylic acid (SFC), is shown. (C) Inhibition of subclass B1 (IMP-1, NDM-1, and VIM-2), B2 (SFH-1), and B3 (L1 and SMB-1) MBLs by SFC. Data represent the means ± standard deviations (SD) of results from three replicate experiments. (D) Heat maps obtained from checkerboard analyses of IMP-1-producing E. coli strains (E. coli DH5α/pBC-IMP-1, MPM MIC = 1.0 μg/ml), NDM-1-producing (E. coli DH5α/pBC-NDM-1, MPM MIC = 64 μg/ml), and VIM-2-producing (E. coli DH5α/pBC-VIM-2, CAZ MIC = 16 μg/ml).