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-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].
4-(tert-Butyl)-benzhydroxamic Acid is a PqsR antagonist with IC50s of 12.5 μM and 23.6 μM for E. coli and P. aeruginosa, respectively, and it reduces the production of the virulence factor pyocyanin in P. aeruginosa with an IC50 of 87.2 μM[1].
RhlR antagonist 1 is a highly effective antagonist of the RhlR protein, showing an IC50 value of 26 μM. It exhibits selective antagonistic activity against RhlR, with minimal effect on LasR and PqsR. RhlR antagonist 1 strongly inhibits biofilm formation in both static and dynamic environments and reduces the production of virulence factors, such as rhamnolipid and pyocyanin, in P. aeruginosa. These characteristics make RhlR antagonist 1 a valuable tool for the development of molecules that modulate quorum sensing and control P. aeruginosa infections [1].
F-17 is a promising virulence factor inhibitor, displaying substantial inhibitory effects on biofilm formation, elastase activity, pyocyanin production, and swarming motility. Additionally, F-17 exhibits a strong binding affinity towards LasR and PqsR. Notably, F-17 does not exhibit any discernible cytotoxicity [1].
QZN34 is a PqsR inhibitor which prevents S. aureus biofilm formation, severely damaged established S. aureus biofilms, and perturbed P. aeruginosa biofilm development. The mechanism of action of QZN 34 toward Gram-positive bacteria is shown to involve membrane perturbation and dissipation of transmembrane potential.