Synthesis of pyrazole-based Schiff bases of Chitosan: Evaluation of antimicrobial activity

In this work, a novel series of Schiff base has been reported by the reaction of Chitosan with different substituted pyrazole-4-carbaldehydes in acidic media. The synthesized compounds were characterized by Fourier-transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), X-ray diffraction (XRD) and 13C NMR techniques. Chitosan and the Schiff bases were compared for their antimicrobial activity against the bacteria; Staphylococcus aureus, Bacillus subtilis, Klebsiella pneumonia, Escherichia coli and a fungi, Candida albicans. The results indicated stronger inhibitory effect of the Schiff bases on these microorganisms compared to Chitosan and the extent of inhibition varied with the nature of substitution. •A novel series of Chitosan Schiff base has been reported.•Synthesized compounds were screened for antimicrobial activity.•The results showed good antimicrobial property compared to the parent moiety chitosan.