壳聚糖的复合法降解及降解产物降血糖活性的研究

Research on Chitosan Degradation by Combined Method and Hypoglycemic Activity of its Degradation Products

目的研究复合法降解壳聚糖及降解产物的生物活性方法在纤维素酶降解的后期引入H2O2氧化降解壳聚糖。观察其降解产物对糖尿病小鼠生化指标的影响。结果最佳工艺条件为：纤维素酶降解时酶糖比0．2，pH4．6、50％、时间为3h，后续H2O2降解时H2O2用量为0．8～1．0（ml／g）、75％、时间为1．5h，所得降解产物的平均分子量约为1700。工艺所生产的低聚壳聚糖用量为100mg／kg时具有明显的降血糖生物活性，其功效甚至优于拜糖苹。结论该复合降解工艺具有成本低，易于工业化，而且所得产品具有较高的生物活性。

Objective To investigate chitosan degradated by combined method and production biological activity of degradation. Methods Cbitosan was first degradated by cellulase depolymerization, and then was oxidated by H2O2. The effects of degradation on diabetic mice was observed. Results The optimum cellulase depolymerization conditions were the mass of cellulase to chitosan （n） 0.1, pH4.6,temperature（T） 50℃ and time （t）3h. The optimum H2O2 oxidation conditions were the proportion of H2 02 to chitosan （n）0. 8 - 1 mE/g, temperature（T）75℃, time（t） 1.5h. Under the optimum degradation condition about 1700 oligoehitosan could be obtained. Moreover, the prepared oligochitosan showed obviously lowering blood - glucose activity when given to mice at a dose of 100 mg/kg and its effect was even over acarbose. Conclusion This combined degradation method to chitosan is not only lowly cost and easy to industrialize, but also its preduct has a higher biological activity.