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

PqsR-IN-2 (Compound 19) inhibits pqs system with IC 50 values of 298 ± 182.0 nM and 265 ± 3.4 nM against two different PA strains PAO1-L and PA14, respectively [1]. PqsR-IN-2 significantly reduces pyocyanin production to 36% against a control of 0.1% DMSO at 3 × the IC 50 value in P. aeruginosa strain PAO1-L [1]. PqsR-IN-2 (0-100 μM, 16 h) shows no significant toxicity to A549 cells [1]. Cell Cytotoxicity Assay [1] Cell Line: A549 lung epithelial cells Concentration: 0.1, 1, 12.5, 25, 50, and 100 μM Incubation Time: 16 h Result: Showed no significant toxicity.