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.

Biological Control of Pseudomonas syringae in Tomato Using Filtrates and Extracts Produced by Alternaria leptinellae

“…This antimicrobial activity observed in A. leptinellae E138 filtrates and extracts may be attributed to the secondary metabolites produced by the endophyte, which could possess biocontrol properties. Several studies have already demonstrated this ability of endophytes to produce antimicrobial compounds that effectively inhibit the growth of bacterial pathogens [62,63] or disrupt bacterial communication mechanisms [63][64][65]. This is in clear agreement with the compounds tentatively identified by mass spectrometry in the methanolic fungal extract of A. leptinellae E138: altechromone A, maculosin, ciclo(L-Phe-L-Pro), and phomopsinone A.…”

Na2S2O3 Catalyzed Three‐Component Synthesis and Anti‐Bacterial Activity of 3‐Methyl‐4‐(hetero)arylmethylene isoxazole‐5(4H)‐ones

“…Many drugs containing isoxazole structure have been used in clinic, such as oxacillin, cloxacillin and dichloropenicillin, which are all effective penicillin antibiotics and can be used for bacterial infection [13] . Especially, recent studies have found that substituted isoxazolone has good resistance to some bacteria like Gram negative bacteria, Gram positive bacteria and mycobacterium tuberculosis [14,15] . Thus, the synthesis of isoxazolone derivatives is of great importance.…”

“…[13] Especially, recent studies have found that substituted isoxazolone has good resistance to some bacteria like Gram negative bacteria, Gram positive bacteria and mycobacterium tuberculosis. [14,15] Thus, the synthesis of isoxazolone derivatives is of great importance. At present, some methods were found to synthesize substituted isoxazole-5(4H)-ones such as cyclization of o-propionyl oximes [16] and one-pot three-component reaction of ethyl acetoacetate, hydroxylamine hydrochloride and aromatic aldehydes.…”