Patent ID: 8202971

Claim:
A process for preparing a compound of chitosan saccharified with aminosugar, comprising the steps of: a) reacting an aminosugar derivative with an anhydride derivative to covalently bond the anhydride derivative as a bonding arm to the aminosugar derivative, comprising: (a1) suspending the aminosugar derivative in a first mixed solution comprising methanol and sodium methoxide, wherein a concentration of the aminosugar derivative is 1˜10%, a weight of the sodium methoxide is 0.5˜3 times as great as a weight of the aminosugar derivative, a stirring speed is 30˜80 r/min, a reacting temperature is 20˜30° C., a reacting time is 2˜4 hours, the reacting is protected by an inert gas, then (a2) adding the anhydride derivative into the first mixed solution drop by drop to react, wherein a mole ratio of the anhydride derivative to the aminosugar derivative is 1:1, a stirring speed is 30˜80 r/min, a reacting temperature is 20˜30° C., a reacting time is 24˜60 hours, and then (a3) adding 0.1M hydrochloric acid until a pH=6 to end reacting, drying under 40˜60° C., recrystallizing with absolute alcohol, and processing vacuum drying to obtain a monosaccharide derivative having an end group of carboxyl; and b) reacting the monosaccharide derivative having an end group of carboxyl obtained in the step a) with an chitosan derivative to covalently bond the monosaccharide derivative having an end group of carboxyl to a primary amino group of the chitosan derivative via the carboxyl, comprising: (b1) dissolving the monosaccharide derivative having an end group of carboxyl which is obtained in the step a) with distilled water, and controlling a concentration thereof in 0.5˜10%, and adjusting a pH thereof to 5˜7 with 0.1M hydrochloric acid, so as to obtain a monosaccharide solution, (b2) dissolving the chitosan derivative which has a degree of deacetylation of 50˜100% into a solution comprising 0˜80% methanol, and controlling a concentration of the chitosan derivative in 0.5˜10%, so as to obtain a chitosan solution, then (b3) mixing the monosaccharide solution with the chitosan solution to obtain a second mixed solution, wherein a stirring speed is 30˜80 r/min, a reacting temperature is 20˜30° C., a reacting time is 48˜72 hours, (b4) after reacting of step b.3, condensing the second mixed solution by evaporation under 40˜60° C. to reduce a volume thereof to 1/20˜⅕, and then (b5) depositing the condensed second mixed solution with absolute alcohol which is 10˜20 times the volume of the condensed second mixed solution, processing vacuum filtrating, and processing vacuum drying to obtain a solid compound of chitosan saccharified with aminosugar.