Synthesis, characterization, and biological evaluation of new chitosan derivative bearing diphenyl pyrazole moiety

This work reports the synthesis of a new pyrazole derivative by reacting 5-amino-1,3-diphenyl pyrazole with succinic anhydride and bearing the product chemically on the chitosan chains via amide linkage to achieve a new chitosan derivative (DPPS-CH). The prepared chitosan derivative was analyzed by IR, NMR, elemental analysis, XRD, TGA-DTG, and SEM. As compared with chitosan, DPPS-CH showed an amorphous and porous structure. Coats-Redfern results showed that the thermal activation energy for the first decomposition of DPPS-CH is 43.72 KJ mol-1 lower than that required for chitosan (88.32 KJ mol-1), indicating the accelerating effect of DPPS on the thermal decomposition of DPPS-CH. The DPPS-CH manifested a powerful wide spectrum antimicrobial potential against pathogenic gram-positive and gram-negative bacteria and Candida albicans at minute concentrations (MIC = 50 μg mL-1) compared to chitosan (MIC = 100 μg mL-1). The MTT assay proved the toxic properties of DPPS-CH against a cancer cell line (MCF-7) at a minute concentration (IC50 = 15.14 μg mL-1) while affecting normal cells (WI-38) at seven times this concentration (IC50 = 107.8 μg mL-1). According to the current findings, the chitosan derivative developed in this work appears to be a promising material for use in biological domains.