Figure 3.

Checkerboard assays for compounds 21–24 in combination with erythromycin vsE. coli BW25113. In each case, the bounded box in the checkerboard assays indicates the combination of compound and antibiotic resulting in the lowest FICI (see Table 1). OD₆₀₀ values were measured using a plate reader and transformed into a gradient: purple represents growth, white represents no growth. An overview of all checkerboard assays with erythromycin can be found in Supporting Information, Figure S1.