Figure 2.

Intracellular accumulation of compounds (A) 7, (B) 8, (C) 10, and (D) 11 in E. coli cells with different genetic backgrounds. Doubling concentrations of compounds from 1 to 32 μM were added to WT (blue), WT-pore (yellow), ΔtolC (gray), and ΔtolC-pore (orange); cells were incubated at room temperature for indicated periods of time, and fluorescence was measured in real time. Data from at least two independent experiments were fitted to a two-exponential equation to extract the steady-state intracellular concentrations. Error bars are SD (n = 2).