Synthesis, biological activity and in silico studies of pyrazole appended thiosemicarbazone

Abstract

The seven thiosemicarbazones containing pyrazole frame 2a–g have been synthesized under catalyst-free condition. All the compounds have been characterized by means of nuclear magnetic resonance, and mass spectrometric data. The antimicrobial efficacy was evaluated in vitro against Gram-positive and Gram-negative bacterial strains, subsequently leading to the determine the minimum inhibitory concentration (MIC) of the compounds. It was observed that the synthesized thiosemicarbazones 2a (30.5 ± 0.0991 μM) and 2f (30.3 ± 0.1251 μM) was found to be more potent against E-coli comparable with streptomycin, as a standard. The molecular docking studies indicated that, these compounds have good binding affinity through hydrogen and amide-π stacked interactions. Including, the half minimum inhibition concentration against antioxidative activity has been also studied. Amongst, the compound 2a (IC50 = 1.139 ± 0.11 μM) and 2f (IC50 = 1.212 ± 0.13 μM) were found be more potent towards antioxidant activity.