Exploring rose absolute and phenylethyl alcohol as novel quorum sensing inhibitors in Pseudomonas aeruginosa and Chromobacterium violaceum.

Inter-cellular signaling, referred to as quorum sensing (QS), regulates the production of virulence factors in numerous gram-negative bacteria, such as the human pathogens Pseudomonas aeruginosa and Chromobacterium violaceum. QS inhibition may provide an opportunity for the treatment of bacterial infections. This represents the initial study to examine the antibiofilm and antivirulence capabilities of rose absolute and its primary component, phenylethyl alcohol. QS inhibition was assessed by examining extracellular exopolysaccharide synthesis, biofilm development, and swarming motility in P. aeruginosa PAO1, along with violacein production in C. violaceum ATCC 12472. Molecular docking analysis was conducted to explore the mechanism by which PEA inhibits QS. Our results indicate that rose absolute and PEA caused decrease in EPS production (60.5-33.5%), swarming motility (94.7-64.5%), and biofilm formation (98.53-55.5%) in the human pathogen P. aeruginosa PAO1. Violacein production decreased by 98.1% and 62.5% with an absolute (0.5 v/v %) and PEA (2 mM). Moreover, the molecular docking analysis revealed a promising competitive interaction between PEA and AHLs. Consequently, this study offers valuable insights into the potential of rose absolute and PEA as inhibitors of QS in P. aeruginosa and C. violaceum.

Promoting antihepatocellular carcinoma activity against human HepG2 cells via pyridine substituted palladium complexes: in vitro evaluation and QSAR studies.

Bis(4-(4-nitrobenzyl)pyridine)dichloropalladium(II), [PdCl2L12], bis(2-amino-5-bromopyridine)dichloropalladium(II), [PdCl2L22], bis(2,4-dimethylpyridine)dichloropalladium(II), [PdCl2L32], bis(3,4-dimethylpyridine)dichloropalladium(II), [PdCl2L42] were prepared. The spectroscopic techniques (FT-IR and 1H-NMR, 13C-NMR) were used to characterize the compounds. Theoretical calculations were used to validate the experimental results. The LanL2DZ-based DFT/B3LYP method was used to define the most stable possible molecular structure for the complexes. Potential energy distribution analysis was performed to determine the theoretical vibration bands of the complexes. Molecular electrostatic potential maps, boundary molecular orbitals and Mulliken charge distribution were used to determine the active sites of the molecules. The interaction mechanisms between the complexes and liver cancer protein were investigated via molecular docking. The study on the antiproliferative effects of these complexes on hepatocellular carcinoma cells (HepG2) showed that they are potent candidates for use against this liver cancer cell line.