PqsR-IN-1 (Compound 18) is a potent inhibitor of PqsR, which is a transcriptional regulator involved in the quorum sensing mechanism of Pseudomonas aeruginosa. This compound effectively reduces the production of pyocyanin and exhibits minimal cytotoxicity [1].

PqsR-IN-1 (Compound 18) inhibits pqs system with IC 50 values of 313 ± 156.2 nM and 342 ± 39.4 nM against two different PA strains PAO1-L and PA14, respectively [1]. PqsR-IN-1 significantly reduces pyocyanin production to 23% against a control of 0.1% DMSO at 3 × the IC 50 value in P. aeruginosa strain PAO1-L [1]. PqsR-IN-1 (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.