as Inhibitor of Quorum Sensing System and Biofilm Forming Ability of .

Endophytic fungi provide rich reservoir for novel antimicrobial compounds. An endophytic fungus, from plant identified as , was investigated for attenuating the quorum sensing mediated pathogenicity of PAO1. Crude extract of was found to reduce the production of redox-active pigments-pyocyanin and pyoverdine in PAO1 by 92.46% and 71.55%, respectively at sub-MIC concentration of 900 μg/mL. In addition, the crude extract was also able to inhibit the expression of virulence factors involved in biofilm formation: exopolysaccharide (72.21%) and alginate (72.50%). Secretion of cell-lytic enzymes was also found to be reduced: chitinase by 79.73% and elastase by 74.30%. 3-Isobutylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione identified from GC-MS analysis, displayed favorable molecular interactions with transcriptional regulators, LasR and RhlR with good docking scores of - 6.873 kJ/mol and - 6.257 kJ/mol, respectively. The study thus reveals the potential use of for discovering drugs against infectious pathogens.