Fig. 3.

Graphical description of the inhibitor accumulation experiments. The key idea of the method is to measure the change of extracellular inhibitor concentration, after incubation of the compound in the presence of H. pylori cells, to estimate the intracellular accumulation of the tested compound. Quantification of the extracellular concentration of inhibitors in the supernatants was done with the aid of one or more detection methods: ultra-performance liquid chromatography–tandem mass spectrometry, UV absorption measurement or determination of the inhibition of the target enzyme for the tested compound, as described in “Materials and methods” (based on Zhou et al. 2015)