Synthesis and characterization of selenourea-functionalized chitosan derivatives with enhanced antioxidant activity

Selenium, an essential micronutrient for human health, has garnered significant interest owing to its multifaceted biological activities including antioxidant, anti-inflammatory, and antitumor properties. In this study, 14 novel chitosan derivatives bearing selenourea groups were synthesized by incorporating selenium into chitosan via nucleophilic substitution reactions. Structural confirmation was achieved through FTIR, ¹H NMR, and ICP-MS analyses, confirming successful selenium incorporation. The derivatives demonstrated superior antioxidant performance, achieving >85 % DPPH radical scavenging at 0.8 mg/mL and exceptional superoxide anion radical inhibition (>95 % at 0.4 mg/mL), surpassing conventional urea-chitosan analogues (<75 % under identical conditions) from our previous study. Biocompatibility was assessed via MTT assay, revealing no significant cytotoxicity in L929 cells at concentrations ≤125 μg/mL. These selenourea-modified chitosan derivatives demonstrate potential as novel selenium-enriched dietary supplements and antioxidants for health foods and pharmaceuticals.