漆酶-TEMPO体系选择性氧化壳聚糖C-6伯羟基提高其抗氧化性能的研究

Study on the selective oxidation of the C-6-hydroxyl of chitosan by laccase-TEMPO system to improve antioxidant capability of the product

利用漆酶-TEMPO体系选择性地氧化壳聚糖C-6伯羟基,对氧化产物分别进行红外光谱、13C NMR、离子色谱和热失重分析,确定产物结构的变化,并进一步对其抗氧化性进行研究。结果表明,经漆酶-TEMPO体系氧化后,壳聚糖分子结构中的C-6伯羟基被选择性地氧化成羧基,其它结构基本不变,其产物为氧化壳聚糖钠盐;壳聚糖氧化产物与原样相比,热稳定性得到了提高;壳聚糖经漆酶-TEMPO体系氧化后的ABTS自由基清除率5min后达到66.36%,抗氧化性能得到改善。

Research adopting laccase-TEMPO system to selectively oxidise the C-6-hydroxyl of chitosan,the FT-IR,^13 C NMR,Na^＋ chromatogram and TGA were used to characterize oxidation products,and further to study its antioxidant capability.Results showed that the C-6-hydroxyl of chitosan were selectively oxidised to carbox-yl,and other basic structure unchanged,the product is sodium salt of oxidised chitosan;compared to the oxida-tion product of chitosan with the original,can improve the thermal stability;after standing for 5 min,the oxi-dation product of chitosan provided an ABTS·＋ radical scavenging ability of 66.36%,indicate that antioxidant capability of the oxidation product was improved.