Synthesis and in vitro antimicrobial evaluation of benzothiazolylindenopyrazoles

In the present study, a series of benzothiazolylindenopyrazoles 5a-o has been efficiently synthesized by refluxing a solution of 2-(3-substitutedbenzoyl)-(1H)-indene-1,3(2H)-diones 1a-c and 2-hydrazinylbenzo[d]thiazole/2-hydrazinyl-6-substitutedbenzo[d]thiazoles 4a-e in presence of dry ethanol and glacial acetic acid in good yields. The newly synthesized derivatives 5a-o were well characterized by using different physical and spectral techniques (FTIR, H-1 NMR, C-13 NMR and HRMS). All the derivatives 5a-o were subjected to their preliminary antimicrobial assay against two Gram-positive bacterial strains [Bacillus subtilis (MTCC 441) and Staphylococcus aureus (MTCC 7443)], two Gram-negative bacterial strains [Escherichia coli (MTCC 1652) and Pseudomonas aeruginosa (MTCC 424)], and two fungal strains [Candida albicans (MTCC 227) and Aspergillus niger (MTCC 8189)] employing serial dilution method using Ciprofloxacin and Fluconazole as standard drugs for bacterial and fungal strains, respectively. Among all the tested derivatives, 5m (MIC = 0.0255 mu mol/mL) and 5o (MIC = 0.0232 mu mol/mL) exhibited maximal inhibition against fungal strain C. albicans. Overall, the investigation revealed that the titled compounds were found more potent against C. albicans.