In the current study, five novel urea-functionalized chitosan derivatives were synthesized via condensation reactions of chloroacetyl chitosan (CTCS) with urea groups bearing nitrogen-containing heterocycles. In order to identify the structure characteristics of chitosan derivatives, FT-IR, ¹H NMR spectroscopy, and elemental analysis were carried out. The antifungal activity of the derivatives against four species of phytopathogen (Fusarium oxysporum f. sp. niveum, Phomopsis asparagus, Fusarium oxysporum f. sp. cucumebrium Owen, and Botrytis cinerea) was evaluated. Furthermore, the antioxidant activity of chitosan derivatives was tested by hydroxyl-radical scavenging and superoxide-radical scavenging assays. The results indicated that chitosan derivatives bearing urea groups displayed superior bioactivity compared with chitosan. Besides, L929 cells were adopted for cytotoxicity test of chitosan and synthesized samples by CCK-8 assay and all samples showed decreased cytotoxicity. These results suggested that the novel urea-functionalized chitosan derivatives could be an ideal biomaterial for antifungal and antioxidant applications.

在当前的研究中，通过氯乙酰壳聚糖（CTCS）与带有含氮杂环的脲基团的缩合反应合成了五种新颖的脲官能化壳聚糖衍生物。为了鉴定壳聚糖衍生物的结构特征，进行了FT-IR，¹ H NMR光谱和元素分析。针对四种植物病原菌的衍生物的抗真菌活性（尖孢镰刀菌和发音属niveum，拟茎点霉芦笋，尖孢镰孢F。菌属cucumebrium欧文，和灰葡萄孢）进行了评估。此外，壳聚糖衍生物的抗氧化活性通过羟基自由基清除和超氧化物自由基清除测定来测试。结果表明，带有壳基的壳聚糖衍生物比壳聚糖具有更好的生物活性。另外，采用L929细胞进行壳聚糖和合成样品的细胞毒性测试（通过CCK-8分析），所有样品均显示出降低的细胞毒性。这些结果表明，新型脲官能化的壳聚糖衍生物可能是抗真菌和抗氧化剂应用的理想生物材料。