Method for preparing chitosan oligosaccharide by degrading chitosan by performing enzymatic hydrolysis and clean oxidation coupling

Abstract

The invention provides a method for preparing chitosan oligosaccharide by degrading chitosan by performing enzymatic hydrolysis and clean oxidation coupling. The method for preparing the chitosan oligosaccharide by degrading the chitosan by performing enzymatic hydrolysis and clean oxidation coupling comprises the following steps: (1) weighing chitosan so as to prepare a chitosan solution of certain concentration, and adding activated degrading enzyme so as to be subjected to enzymatic hydrolysis reaction, thereby obtaining a primary chitosan degradation solution; (2) adding a hydrogen peroxide solution into the primary chitosan degradation solution so as to be subjected to oxidative degradation reaction, thereby obtaining a degradation solution containing chitosan oligosaccharide; and (3)naturally cooling the degradation solution containing the chitosan oligosaccharide to room temperature, carrying out filtration so as to obtain a filtrate, removing unreacted solid chitosa raw-material from the filtrate, adding anhydrous alcohol into the filtrate so as to be subjected to alcohol precipitation to separate the chitosan oligosaccharide out, and performing decompressing-drying on theseparated chitosan oligosaccharide, thereby obtaining the chitosan oligosaccharide. By taking the chitosan as the raw material, as well as adopting the enzymatic hydrolysis and oxidative degradationcoupling technology, the method for preparing the chitosan oligosaccharide is capable of realizing convenient, efficient, economical and clean preparation of chitosan oligosaccharide; and moreover, the method has significant characteristics of being simple in technique, mild in reaction conditions, high in yield and clean in process. Thus, the method for preparing the chitosan oligosaccharide by degrading the chitosan by performing enzymatic hydrolysis and clean oxidation coupling is a chitosan oligosaccharide preparation technology with industrial application prospects.

Description

technical field [0001] The invention relates to the field of natural polymer degradation and fine transformation, in particular to a method for preparing chitosan oligosaccharide by degrading chitosan coupled with enzymatic hydrolysis and clean oxidation. Background technique [0002] Chitosan is a derivative of chitin after deacetylation, and its yield in nature is second only to cellulose (document: Rojas G, Silva J, Flores JA, et al. Adsorption of chromium onto cross-linked chitosan[J] .Separation and Purification Technology, 2005, 44 (1): 31-36.), is the only natural basic amino polysaccharide found so far, the free amino group after its deacetylation has a positive charge, making chitosan present Unique characteristics and a variety of physiological activities, but due to the large molecular weight of chitosan, it is insoluble in some common solvents such as water, which greatly limits its application. Oligochitosan is a high-end derivative obtained from the degradatio...

AI Technical Summary

Problems solved by technology

Lin Qiang et al. used cellulase and hydrogen peroxide to degrade chitosan. The optimal reaction conditions were: pH 5.6, enzyme / sugar 0.1, reaction temperature 54°C, reaction time 6 hours. 0.5h before the end of the reaction, add a certain amount of hydrogen peroxide for oxidative degradation to obtain chitosan oligosaccharides with an average molecular weight of 1500 (document: Lin Qiang, Ma Keli. Cellulase-hydrogen peroxide degradation method to prepare chitosan oligosaccharides [J]. Marine Science, 2003.27 (6): 7.), the reaction time is relatively long, the price of cellulase is relatively high, and the yield data of the product are not given, so it is impossible to evaluate its advanced nature