Synthesis and characterization of water-soluble chitosan derivatives: spectral, thermal and biological studies. Issue 12 (1st December 2020)

• Record Type: Journal Article
• Authors: Lal, Sohan; Arora, Sanjiv; Rani, Shikha; Kumar, Parvin; Dabas, Pooja; Malik, Jaideep
• Is Part Of: Journal of macromolecular science. Volume 57:Issue 12(2020)
• Page Start: 791
• Page End: 799
• Publication Date: 2020-12-01
• Subjects: Antimicrobial activity -- metal complexes -- Schiff base -- thermal study -- water-soluble O-CMC; Polymers -- Periodicals; Polymerization -- Periodicals; 547.7
• DOI: 10.1080/10601325.2020.1784756
• Languages: English
• ISSNs: 1060-1325

Abstract

Abstract: In this study, different water-soluble derivatives of chitosan were synthesized by treating chitosan with monochloroacetic acid to yield O-carboxymethyl chitosan (O-CMC) and this O-CMC treated with vanillin to form Schiff base. Metal complexes of this Schiff base were prepared with different salt of metal ions like Cu(II), Ni(II), Fe(II) and Zn(II). O-CMC and its Schiff base were characterized by FTIR, 1 H-NMR and all other derivatives were characterized by using FTIR, UV-visible and fluorescence spectroscopic techniques. In FTIR study, the main characteristic peaks were observed at 1744 cm −1 (C = O str. in O-CMC), 1666 cm −1 (C = N str. peak in Schiff base) and 600–640 cm −1 (metal-ligand str.). In 1 H-NMR different signals were obtained at δ 9.58 ppm due to the proton of imine group (–CH = N- in Schiff base) and signals in between δ 6.5 and 7.5 ppm due to aromatic protons. Antimicrobial activity of all these derivatives was also investigated against Bacillus subtilis (Gram-positive bacteria), Escherichia coli (Gram-negative bacteria) and Aspergillus niger (fungi). The result shows that Ni- and Zn-complexes of O-CMC Schiff base has almost similar activity as that of standard drug ampicillin. Thermal behavior of all these derivatives was also examined by using TG/DTG techniques. Research Highlights: Water-soluble derivatives of chitosan were synthesized (O-CMC, Schiff base and metal complexes). All derivatives were characterized by using different techniques (FTIR, 1 H-NMR). Thermal, spectral and antimicrobial studies were also carried out. All derivatives are water-soluble and thermally stable and exhibited enhanced antimicrobial activity. Graphical Abstract: