Synthesis, Characterization and Antibacterial Activity of New 5-Aryl Pyrazole Oxime Ester Derivatives

Eleven new 1-{5-[4-(benzyloxy)phenyl]-3-methyl-4,5-dihydropyrazol-1-yl} oxime ester derivatives were synthesized and characterized by elemental analysis, HRMS, 1H NMR data. All the compounds were screened for their antibacterial potential in vitro against Bacillus subtilis, Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The results indicate that compounds 8c and 8f possess potent activity with the minimum inhibitory concentrations(MIC) of 1.562-3.125 μg/mL against all the four bacteria. Compounds 8c, 8e and 8f show moderate inhibition against the DNA gyrase(IC50=1.9-2.5 μg/mL). On the basis of the biological activities, structure-activity relationship was discussed.