Biologically Active Water Soluble Novel Biopolymer/Hydrazide Based O-Carboxymethyl Chitosan Schiff Bases: Synthesis and Characterisation

Six new N , N , O tridentate water soluble hydrazide based O -carboxymethyl chitosan Schiff base derivatives have been prepared through in-situ synthesis. The degree of substitution of schiff base derivatives was calculated theoretically and the derivatives were prepared with 1:1 proportion. Biopolymer Schiff base derivatives with their various bonding sites and different proton-carbon environment were characterised by FT-IR and 1 H, 13 C NMR. The crystallinity of synthesized Schiff bases was studied by X-ray diffraction. Thermal decomposition of all synthesized O -carboxymethyl chitosan Schiff base ligands was investigated by thermo gravimetric analysis which revealed the presence of Schiff base functionality to elongate the temperature to > 300 ºC. Scanning electron microscopic studies revealed that O -carboxymethyl chitosan Schiff base derivatives were affecting the crystallinity of chitosan. Additionally, the synthesized novel Schiff base derivatives were characterized for anti-inflammatory, total antioxidant and antidiabetic studies and they showed better biological and pharmaceutical results with standard drug. Graphic Abstract