PqsR-IN-2 (Compound 19) is a highly potent inhibitor of PqsR, the transcriptional regulator of quorum sensing in Pseudomonas aeruginosa. It efficiently suppresses pyocyanin production without significant cytotoxicity, making it a promising candidate for therapeutic applications [1].

PqsR-IN-2 (Compound 19) effectively inhibits the pqs system in Pseudomonas aeruginosa, with IC50 values of 298 ± 182.0 nM and 265 ± 3.4 nM against PAO1-L and PA14 strains, respectively [1]. It also significantly reduces pyocyanin production in the PAO1-L strain to 36% at 3× IC50 concentration, compared to a 0.1% DMSO control [1]. Importantly, PqsR-IN-2 shows negligible toxicity towards A549 lung epithelial cells across concentrations (0-100 μM) after 16 hours of exposure, as demonstrated in a cell cytotoxicity assay [1].