One-step procedure for enhancing the antibacterial and antioxidant properties of a polysaccharide polymer: Kojic acid grafted onto chitosan

The purpose of this work was to develop a nontoxic bioactive material based on a natural pyrone compound (kojic acid, KA) and chitosan oligosaccharides (COS). The bioactive material, chitosan oligosaccharide-N-kojic acid polymer (COS-N-KA), was prepared by one-step environmentally friendly approach. Then, the physicochemical properties and biological activities of COS-N-KA as a prepared water-soluble COS derivative were evaluated. The polymer was characterized by using UV-vis, FTIR, H-1 NMR, and C-13 NMR spectroscopy, Mw, PID, TGA, water solubility, hemolysis assay, and animal toxicity studies. Particularly, the antioxidant and antimicrobial assays revealed that COS-N-KA significantly enhanced the antimicrobial and antioxidant activities, which remarkably stronger than that of free COS and KA. Hence, the low hemolytic activity to human red blood cells, and nontoxic to female mice of SLAC KM strain made this novel polymer material a promising and effective compound for food and pharmaceutical industries. (C) 2018 Elsevier B.V. All rights reserved.