Preparation and Characterization of Polyphenol-Functionalized Chitooligosaccharide Pyridinium Salts with Antioxidant Activity.

As a kind of eco-friendly material with wide application prospects, chitooligosaccharide (COS) has attracted increasing attention because of its unique bioactivities. In this study, novel polyphenol-functionalized COS pyridinium salts were designed and synthesized. The structural characteristics of the desired derivatives were confirmed by FT-IR and H NMR spectroscopy. Their antioxidant activities were evaluated in vitro by DPPH radical scavenging assay, superoxide anion radical scavenging assay, and reducing power assay. The solubility assay in common solvents and cytotoxicity assay against L929 cells using the MTT method in vitro were also performed. The antioxidant assay results showed that the compounds functionalized by polyphenol displayed improved antioxidant activities, which were enhanced with the increase of sample concentration and the number of phenolic hydroxyl groups. The solubility assay indicated that the prepared derivatives had good water solubility. Besides, the modified products were non-toxic to the cells tested. In short, the polyphenol-functionalized COS pyridinium salts with enhanced antioxidant activity and good biocompatibility could be employed as newly safe antioxidant in the fields of biomedicine and food.