Synthesis and antimicrobial studies of novel derivatives of 4-(4-formyl-3-phenyl-1H-pyrazol-1-yl)benzoic acid as potent anti-Acinetobacter baumannii agents

Abstract

Microbial resistance to antibiotics is a global concern. The World Health Organization (WHO) has identified antimicrobial resistance as one the three greatest threats for human beings in the 21st century. Without urgent and coordinated action, the world is moving toward a post-antibiotic era, in which normal infections or minor injuries may become fatal. In an effort to find new agents, we report the synthesis and antimicrobial activities of 40 novel 1,3-diphenyl pyrazole derivatives. These compounds have shown zones of growth inhibition up to 85 mm against Acinetobacter baumannii. We tested the active compounds against this Gram-negative bacterium in minimum inhibitory concentration (MIC) tests and found activity with concentration as low as 4 μg/mL.

Synthesis and antimicrobial studies of hydrazone derivatives of 4-[3-(2,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid and 4-[3-(3,4-difluorophenyl)-4-formyl-1H-pyrazol-1-yl]benzoic acid

“…Compounds showing activity against tested bacteria were also evaluated for growth inhibition of Human Embryonic Kidney (HEK-293) cell line at 25 and 50 μg/mL concentration via resazurin assay. 13 To our delight, none of these active compounds showed any significant growth inhibition at 25 μg/mL concentration. HEK293 cells also tolerated the active compounds at 50 μg/mL concentration after incubating for 24 h. Cell viability was more than 80% for all the compounds except 6e , which showed 69% viability at 50 μg/mL concentration (Fig.…”

“…13,19 To our delight, we found several molecules with broader and several fold improved activities against both Gram-positive and Gram-negative bacteria. Reaction of 4-hydrazinobenzoic acid ( 1 ) with bisfluoro acetophenyl derivatives ( 2 ) led to the formation of hydrazones ( 3 ).…”

Hybrid Approach for Synthesis and Antimicrobial Activity of Heterocyclic Compounds

“…Singlet signal of pyrazole ring was given by C 5 -H at 7.96 ppm. All other aromatic 13 protons showed multiple in range of 6 4 and C 5 signals appeared at 149.5, 123.8 and 117.8 ppm. One carbon of -CH=N-displayed peak at 156.3 ppm.…”

“…IR spectra of all compounds were recorded on a Perkin-Elmer FT-IR spectrophotometers in KBr. 1 H NMR and 13 C NMR spectra were recorded on Varian Gemini 500 MHz in DMSO-d 6 as a solvent and tetramethylsilane (TMS) as an internal standard. Mass spectra were scanned on a Shimadzu LC-MS 2010 spectrometer.…”

“…1) celecoxibe, zibotentan and sulphapyridine sequentially contain pyrazole [4], 1,3,4-oxadiazole [5] and pyridine heterocycles. Among the important heterocyclic scaffolds of biological and pharmacological interest, the pyrazole ring is able with diverse medicinal activities [6][7][8][9][10][11][12].…”