School of Food Science and Biotechnology, Zhejiang Gongshang University, Xiasha, Hangzhou, Zhejiang 310018, PR China.
Department of Food Science, Faculty of Hospitality Management, Shanghai Business School, Shanghai 200235, PR China.
Food Chem. 2023 Sep 15;420:136093. doi: 10.1016/j.foodchem.2023.136093. Epub 2023 Apr 7.
Two novel chitosan oligosaccharide (COS)-hydroxypyridone (HPO) conjugates were prepared by reacting chitosan oligosaccharide with 2-chloromethyl-5-hydroxypyridone (HPO), which was synthesized by a series of reactions starting from kojic acid. The degree of substitution of COS-HPO2 reached 1.2, with a yield of 74.9%. The structure of the two conjugates (COS-HPO1 and COS-HPO2) was identified by NMR and FT-IR analysis. The two conjugates showed significantly higher free radical (DPPH•, ABTS and •OH) scavenging activity and reducing power than those of COS and HPO (p < 0.05). Both COS-HPO1 and COS-HPO2 possessed significantly stronger tyrosinase inhibitory activity than those of COS, with IC values of 0.67 and 0.28 mg/mL for monophenolase, 0.73 and 0.30 mg/mL for diphenolase, respectively. In addition, the conjugates were found to be non-toxic to RAW264.7 macrophages and MRC-5 human lung cells. This work proposes a facile method to enhance the oxidative and tyrosinase inhibitory properties of COS.
两种新型壳聚糖寡糖（COS）-羟基吡啶酮（HPO）缀合物是通过壳聚糖寡糖与 2-氯甲基-5-羟基吡啶酮（HPO）反应制备的，HPO 是由曲酸经一系列反应合成的。COS-HPO2 的取代度达到 1.2，产率为 74.9%。通过 NMR 和 FT-IR 分析鉴定了两种缀合物（COS-HPO1 和 COS-HPO2）的结构。与 COS 和 HPO 相比，两种缀合物均显示出显著更高的自由基（DPPH•、ABTS 和 •OH）清除活性和还原能力（p < 0.05）。COS-HPO1 和 COS-HPO2 对酪氨酸酶的抑制活性均显著强于 COS，对单酚酶的 IC 值分别为 0.67 和 0.28 mg/mL，对二酚酶的 IC 值分别为 0.73 和 0.30 mg/mL。此外，还发现这些缀合物对 RAW264.7 巨噬细胞和 MRC-5 人肺细胞无毒性。本工作提出了一种增强 COS 的氧化和酪氨酸酶抑制性能的简便方法。
