Synthesis of New Benzofuran-Pyrazole Hybrids as Potential Antibiofilm Agents

A new series of 3-aryl/heteroaryl-5-benzofurnyl pyrazoles [5(a-l)] were synthesized from 1,3-β-monothiodiketones through the cyclocondensation reaction with phenyl hydrazine in good yield and characterized by IR, 1H and 13C NMR, Mass and elemental analyses. All compounds were subjected to evaluate antimicrobial activity against various bacteria viz Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Klebsiella pneumoniae and fungal strains viz Fusarium oxysporum and Aspergillus flavus. Further, the inhibition of biofilm formation of Pseudomonas aeruginosa was also carried out. The results showed that some of the synthesized compounds displayed significant antimicrobial activity against tested pathogens. Compounds bearing 3,4,5-trimethoxy (5c) and 4-chloro (5j) substituents on phenyl ring of pyrazole showed the prominent activity against all strains except Lactobacillus species. Among the compounds screened for antibiofilm activity, compounds 5b-d recorded good antibiofilm potential with <50% biofilm formation at 100 μM of which 5b recorded MIC as low as 20 μM.