Synthesis, biological evaluation, and molecular docking of some new oxadiazole-incorporated pyrazole derivatives as potent antimicrobial agents

Our continuous effort in search of potent clubbed heterocycles and their newly designed derivatives, we have synthesized a series of some new of 1-(3,5-substituted diphenyl-4,5-dihydro-1-pyrazol-1-yl)-2-((5-phenyl-1,3,4-oxadiazol- 2-yl)thio)ethan-1-ones (5a-o) by reacting 5-phenyl-1,3,4-oxadiazole-2-thiol (4) with 2-chloro-1-(3-(substituted phenyl)-5- substituted phenyl-4,5-dihydro-1H-pyrazol-1-yl)ethan-1-ones (3a-o). In silico molecular docking of new compounds has been demonstrated against 1BAG, 1JIJ, 1KZN, and 1Y54 using ciprofloxacin as a standard drug to ensure their potential. All compounds 5a-o were subjected to antibacterial and antifungal biological evaluation. Antibacterial screening was carried out against two different Gram +ve strains Staphylococcus aureus and Bacillus subtilis as well as two Gram -ve strains, Escherichia coli and Enterobacter aerogenes. Antifungal activities were carried out against Candida albican and Aspergillus niger. Compound 5o showed excellent inhibition values of 37, 23, 20, and 20 mm against S. aureus, B. subtilis, E. coli, and E. aerogenes, respectively, whereas compound 5e exhibited good antibacterial activities against Gram-negative stains. We observed that compounds having electron-withdrawing groups are more effective against the Gram-positive strain, whereas compounds bearing electron-donating groups have displayed tremendous antifungal activities.. KEYWORDS :Antibacterial, Antifungal, Molecular docking, Oxadiazole, Pyrazole.