Method for degrading chitosan

A technology of chitosan and chitosan solution, which is applied in chemical instruments and methods, amino sugar, sugar derivatives, etc., can solve the problems of slow degradation rate and chitosan structure damage, and achieve high reaction rate and fast reaction , Improve the effect of reaction conditions

Inactive Publication Date: 2012-10-03
INST OF OCEANOLOGY - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The oxidative degradation method is a low-cost and environmentally friendly method, but the degradation rate of chitosan using hydrogen peroxide alone is slow, and the use of high-concentration hydrogen peroxide may cause damage to the structure of chitosan

Method used

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  • Method for degrading chitosan
  • Method for degrading chitosan

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] High molecular weight chitosan (658kDa) 2g is dissolved in 100ml 2% (mass fraction) acetic acid to obtain chitosan solution, in chitosan solution, add the hydrogen peroxide of a certain amount (accounting for the volume fraction of chitosan solution by hydrogen peroxide), The final concentration of hydrogen peroxide is as figure 1 As shown, two modes of traditional heating and microwave heating were used to degrade chitosan. The reaction temperature was controlled at 70°C, and the degradation was performed for 20 minutes. In the microwave mode, the microwave power was 600W. The molecular weight was determined by gel size exclusion chromatography, such as figure 1 As shown, under the same temperature and degradation time conditions, the concentration of hydrogen peroxide needed to degrade chitosan with similar molecular weight in the microwave-assisted mode is significantly lower than that in the traditional heating mode.

Embodiment 2

[0021] High molecular weight chitosan (658kDa) 2g is dissolved in 100ml 1% (mass fraction) hydrochloric acid to obtain chitosan solution, in chitosan solution, add 1ml 30% hydrogen peroxide, at microwave power 600W, control reaction temperature is 70 ℃, Degrade for 10 minutes, neutralize the reacted solution with lye to neutrality, precipitate with alcohol, collect the precipitate after centrifugation, and freeze-dry to obtain chitosan with low molecular weight. The resulting product was determined to have a molecular weight of 41.2kDa ( Figure 2B shown), the infrared spectrum of the degradation product was compared with that of the initial chitosan raw material ( image 3 Shown), found the characteristic absorption peak 1643cm of raw material chitosan -1 (amide I), 1558cm -1 (Amide II), 1322cm -1 (amide III), 1158895cm -1 (The characteristic absorption peak of the basic skeleton of the sugar ring) still exists after degradation, indicating that the basic structure of chi...

Embodiment 3

[0023] High molecular weight chitosan (658kDa) 2g is dissolved in 100ml 1% (mass fraction) acetic acid to obtain chitosan solution, in chitosan solution, add 1ml 30% hydrogen peroxide, at microwave power 600W, control reaction temperature is 70 ℃, After degrading for 30 minutes, the reacted solution was neutralized with lye to neutrality, alcohol precipitation was performed, and the precipitate was collected after centrifugation, and then freeze-dried to obtain chitosan with low molecular weight. The resulting product was determined to have a molecular weight of 9.0kDa ( Figure 2C shown), the infrared spectrum of the degradation product was compared with that of the initial chitosan raw material ( image 3 Shown), found the characteristic absorption peak 1643cm of raw material chitosan -1 (amide I), 1558cm -1 (Amide II), 1322cm -1 (amide III), 1158895cm -1 (The characteristic absorption peak of the basic skeleton of the sugar ring) still exists after degradation, indicati...

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Abstract

The invention belongs to the marine chemistry engineering technology, and in particular relates to a method for degrading chitosan by hydrogen peroxide with the help of microwave temperature control, comprising the following steps: dissolving high molecular weight chitosan with dilute acid to obtain a chitosan solution; adding hydrogen peroxide in the chitosan solution for reaction under microwave; and heating the obtained solution and controlling the reaction temperature under microwave to obtain chitosan of different molecular weights at different degradation time. Compared with the conventional way of degrading chitosan by heating the hydrogen peroxide, hydrogen peroxide of a lower concentration is required at the same temperature, a low molecular weight chitosan can be obtained in less time, and the basic chemical structure of the obtained low molecular weight chitosan is basically the same as that of the initial chitosan raw material.

Description

technical field [0001] The invention belongs to marine chemical engineering technology, and in particular relates to a method for degrading chitosan with the aid of microwave temperature control by hydrogen peroxide. Background technique [0002] Chitosan is a natural linear polysaccharide composed of glucosamine and acetylglucosamine linked by β-1,4 glycosidic bonds. Because chitosan is rich in sources, safe and non-toxic, has good biocompatibility, and has good compatibility with human cells, it has great application potential in the fields of food, medicine, agriculture, and material science. Low molecular weight chitosan and oligochitosan are degradation products of chitosan. Compared with chitosan, the water solubility of low molecular weight chitosan and chitooligosaccharide is greatly improved, which is beneficial to the absorption and utilization of organisms. Low-molecular-weight chitosan and chitosan have been found to have various physiological activities, such ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C08B37/08C07H5/06C07H1/00
Inventor 李鹏程李克成邢荣娥刘松于华华秦玉坤孟祥涛
Owner INST OF OCEANOLOGY - CHINESE ACAD OF SCI
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