Hemolytic activities on healthy human erythrocytes of 7 potential YycG inhibitors. The MICs of 7 inhibitors are compound 1 (50 μM), compound 2 (25 μM), compound 3 (12.5 μM), compound 4 (12.5 μM), compound 5 (6.25 μM), compound 6 (100 μM), and compound 7 (0.2 μM), respectively. The MICs of Tet and Cip are both 0.25 μg/ml. Each assay was performed in quadruplicate and repeated twice. The values represented the mean and SD from one separate experiment. Cells with no compounds treatment and with 1% Triton-100 treatment were for the zero and 100% hemolysis controls, respectively. Black and white columns represented the concentrations of 4×MICs and MICs of 7 inhibitors and two conventional antibiotics, respectively. Tet: tetracycline, Cip: ciprofloxacin.