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.