Chitosan oligosaccharide sulfate and preparation method thereof
The present disclosure belongs to the field for preparation of chitosan oligosaccharide, and particularly relates to a chitosan oligosaccharide sulfate and a preparation method thereof. The method is as follows: adding an equal volume of 1.0%-2.0% by mass of potassium sulfate solution into 2.0%-4.0% by mass of chitosan oligosaccharide hydrochloride solution and evenly mixing to obtain a mixed solution, allowing a molar ratio of amino to sulfate ions in the mixed solution to be 2:1, then adding absolute ethyl alcohol to obtain a chitosan oligosaccharide sulfate suspension, standing, filtering, collecting precipitates, washing, drying and smashing to finally obtain the chitosan oligosaccharide sulfate. This method cleverly utilizes a characteristic that the chitosan oligosaccharide sulfate is difficultly dissolved into 75% ethyl alcohol aqueous solution, while potassium chloride is slightly dissolved into 75% ethyl alcohol aqueous solution, the chitosan oligosaccharide sulfate is obtained using a precipitation method. Moreover, the preparation method used in the present disclosure is simple to operate, economic and environmental-friendly, does not need the use of highly corrosive sulfuric acid, and is friendly to operation staffs, environments and production equipment.
1 . A preparation method of a chitosan oligosaccharide sulfate, comprising the following steps: adding an equal volume of 1.0%-2.0% by mass of potassium sulfate solution into 2.0%-4.0% by mass of chitosan oligosaccharide hydrochloride solution and evenly mixing to obtain a mixed solution, allowing a molar ratio of amino to sulfate ions in the mixed solution to be 2:1, then adding absolute ethyl alcohol to obtain a chitosan oligosaccharide sulfate suspension, standing, filtering, collecting precipitates, washing, drying and smashing to finally obtain the chitosan oligosaccharide sulfate; wherein the solvent for washing is a 75% ethyl alcohol aqueous solution.
2 . The preparation method according to claim 1 , wherein the polymerization degree of the chitosan oligosaccharide hydrochloride is 2-10.
3 . The preparation method according to claim 1 , wherein the molecular weight of the chitosan oligosaccharide hydrochloride is less than or equal to 2000 Da.
4 . The preparation method according to claim 1 , wherein a volume ratio of the absolute ethyl alcohol to the mixed solution is 3:1.
5 . The preparation method according to claim 1 , wherein the duration for standing is 10 h.
6 . The preparation method according to claim 1 , wherein the washing is that the collected precipitate is washed three times with a solvent.
7 . The preparation method according to claim 6 , wherein the duration for washing is 10 min/time.
8 . The preparation method according to claim 1 , wherein the temperature of drying is 50° C.-60° C.