Silica supported synthesis and quorum quenching ability of Isoxazolones against both Gram positive and Gram negative bacterial pathogens

Abstract

Isoxazolones are synthesised using easily available, economical and reusable silica (TLC grade) catalyst. High yields are obtained in aqueous reaction system with substrate tolerance without affecting the yield. This multigram scale, purification free method exhibits prospects for a large scale use in future. These compounds were screened for their potential application as quorum quenchers in pathogenic bacteria. The prepared compounds were analysed for quorum quenching (QQ) activity on Gram negative bioreporter strain Chromobacterium violaceum by inhibiting its pigment production i.e. violacein production in a concentration dependent manner. Some Isoxazolone derivatives showed very good quorum quenching activity. Moreover these derivatives also showed very good antibiofilm activity against both Gram negative (Pseudomonas aeruginosa ATCC 27853) and Gram positive (Staphylococcus aureus ATCC 6538) bacterial human pathogens through Quorum Quenching mechanism. Isoxazolones thus have enormous potential to be exploited in the medical field against bacterial infections caused by both Gram negative and Gram positive bacterial human pathogens.