A nano-organo catalyst mediated approach towards the green synthesis of 3-methyl-4-(phenyl)methylene-isoxazole-5(4H)-one derivatives and biological evaluation of the derivatives as a potent anti-fungal and anti-tubercular agent

An efficient and green protocol for the one-pot synthesis of 3-methyl-4-(phenyl)methyleneisoxazole-5(4H)-one derivatives catalyzed by a novel acid functionalized Fe3O4 nanoparticles (NPs) is reported herein. The catalyst was synthesized and characterized by various analytical techniques. Ultrasound energy has been efficiently exploited for the preparation of the catalyst as well as the synthesis of a series of the aforesaid compounds. The salient features of this protocol include mild reaction condition, easy catalyst recovery, shorter reaction time and use of environmental-friendly solvents. In addition, preliminary in-vitro antifungal and antimycobacterial screening of the synthesized compounds were conducted against three pathogenic fungi viz., Aspergillus fumigatus, Aspergillus flavus, Fusarium oxysporum and M. tuberculosis H37Rv respectively. Interestingly, 3-chloromethyl-4-(phenyl) methylene-isoxazole-5(4H)-one series exhibited over 50% growth inhibition against the mycelial growth of the fungi Fusarium oxysporum at 100 & mu;g/ mL. Whereas 4-(1H-indol-3-ylmethylene)-3-methyl-4H-isoxazol-5-one and 3-chloromethyl-4(2,4,6-trimethyl-benzylidene)-4H-isoxazol-5-one displayed antimycobacterial activity against Mycobacterium tuberculosis H37Rv strain equipotent to the standard drug, ethambutol (MIC 1.56 & mu;g/mL).

Automated summary

An efficient and green one-pot synthesis of 3-methyl-4-(phenyl)methyleneisoxazole-5(4H)-one derivatives was achieved using a novel acid functionalized Fe3O4 nanoparticles (NPs) as the catalyst. Ultrasound energy was utilized for the preparation of the catalyst and the synthesis of the compounds. The protocol featured mild reaction conditions, easy catalyst recovery, shorter reaction time, and the use of environmentally friendly solvents. In addition, the synthesized compounds exhibited significant antifungal and antimycobacterial activities.