FIG 1.

Candidate inhibitors of TonB action identified by primary screening. Among the 44 compounds that inhibited fluorescence >30% in the primary FLHTS screening, we selected 20 compounds for further testing and obtained them from suppliers as fresh powders. These chemicals caused dose-dependent inhibition of fluorescence recovery; we did not consider compounds that reduced initial fluorescence and/or the extent of initial quenching. We also tested compound 120304 from reference 71, but it had no effects in our primary or secondary tests of TonB action (see also Table 2).