Preparation of l-Arginine Schiff Bases Modified Chitosan Derivatives and Their Antimicrobial and Antioxidant Properties

We successfully prepared a series ofl-arginine Schiff bases acylated chitosan derivatives, aiming to improve the antioxidant activity and antimicrobial activity of chitosan by introducing a furan ring, pyridine ring, andl-arginine structure. The accuracy of the structures of ten compounds was characterized by FT-IR and1H NMR. In terms of DPPH radical scavenging activity, except for compound CR3PCA, the scavenging rate of other compounds was higher than chitosan, especially CRCF and CRBF had strong scavenging abilities. At the same time, in the superoxide-radical scavenging activity assay, CRCF, CRBF, CR3PCA, CR2C3PCA, and CR2B3PCA were comparable to positive control at 1.60 mg/mL. Simultaneously, CRFF, CRCF, and CRBF had a certain inhibitory effect onBotrytis cinerea. Furthermore, the inhibitory effect of CRFF, CRCF, and CR3PCA onStaphylococcus aureuswas very well, close to the positive control at 1.00 mg/mL. CRCF and CR2B3PCA showed better inhibitory effects onEscherichia colithan other compounds. The MTT assay was used to determine the cytotoxicity of the chitosan derivatives, which proved their safety to fibroblast cells. In summary, the study indicated that some of these compounds have the potential for further development and utilization in the preparation of antioxidants and antimicrobial agents.Keywords:chitosan;l-arginine Schiff bases;heterocyclic compounds