CN101220061A - Method for producing chitosan oligosaccharide with self-warming up oxidative degradation - Google Patents
Method for producing chitosan oligosaccharide with self-warming up oxidative degradation Download PDFInfo
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- CN101220061A CN101220061A CNA2008100066408A CN200810006640A CN101220061A CN 101220061 A CN101220061 A CN 101220061A CN A2008100066408 A CNA2008100066408 A CN A2008100066408A CN 200810006640 A CN200810006640 A CN 200810006640A CN 101220061 A CN101220061 A CN 101220061A
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Abstract
The invention relates to a preparation method of a chito-oligosaccharide, which is precisely a chito-oligosaccharide preparation method by means of self reaction heating and oxidation degradation. The invention firstly heats the water to a temperature of 25 to 60 DEG C, then puts high molecular weight chito-oligosaccharide raw material into the water and mixes well, whereafter adds hydrogen peroxide aqueous and acid and mixes well, and then the degradation reaction begins. The oxidation degradation reaction is exothermic, which needs no extra energy supply for the reaction system after the reaction begins. As the reaction carries on, the material gradually heats while the reaction speed gradually quickens. The even chito-oligosaccharide solution is gained after about two hours when the reaction completes, from which the chito-oligosaccharide powder with less than 2000 Dalton average molecular weight, narrow molecular weight distribution and high physiological activity effective polysaccharide with high content can be gained through direct spray drying, vacuum drying or lyophilization or drying after condensation. The preparation method of the invention can maintain the reaction system in higher temperature without heating for a long period, which needs very few production equipment investment and is characterized by simplicity, convenience, safety, economy, utility, high efficiency, low production cost and having no influence on the environment , etc.
Description
Technical field
The present invention relates to a kind ofly utilize reaction make reaction system maintain low optimal temperature from heating up to carry out the method that oxidative degradation prepares oligochitosan.
Background technology
Chitosan is to reach glucosamine polysaccharide more than 70% by the deacetylation that chitin makes through deacetylation reaction, contains free amine group in the molecule, is alkaline polysaccharide unique in the natural polysaccharide.Usually about hundreds of thousands of, the effect because of hydrogen bond in its molecule can only be dissolved in the minority dilute acid soln molecular weight of chitosan, and can not be directly soluble in water, and its range of application is very limited.Oligochitosan is meant that molecular-weight average is lower than 2000 daltonian chitosans.The chitosan of different molecular weight has different effects, the physiologically active of oligochitosan and their molecular dimension, amino content, physical properties and chemical structure are closely related, show that according to the study molecular weight is that 800～2000 daltonian oligochitosans have the special anticancer physiologically active that waits.Oligochitosan has many functional propertys that are better than the macromolecule chitosan, also has good water-solubility, character such as the humidification of preserving moisture, bacteriostasis antibiosis effect.Peculiar various physiologically actives of oligochitosan and functional property make it have unique using value at aspects such as protective foods, biological medicine, plant-growth promotion, daily cosmetics, make the application of chitosan be able to real realization.Therefore, in the application and product development of chitosan, the problem that must solve is to reduce the molecular weight of chitosan by proper method, the preparation oligochitosan.
The preparation method of oligochitosan mainly comprises hydrolysis method, physics method, utilizes sugared shift reaction, utilizes several big classes such as changeing base is synthetic, chemical synthesis.Based on hydrolysis method, specifically can be divided into acid degradation method, enzyme liberating method and oxidation degradation method at present.
At present the domestic patent of utilizing oxidation degradation method to prepare low-molecular water-soluble chitosan or oligochitosan has: (1) patent No. is the method that 00114484.7 Chinese patent has been announced a kind of high concentration process of preparing water soluble oligomerized chitosan, though its chitosan concentration expressed in percentage by weight＞20～50%, also add acetic acid or hydrochloric acid and promoted reaction, but because its first step is that the macromole chitosan is dispersed in concentration expressed in percentage by weight is in 0.01～2.0% the aqueous hydrogen peroxide solution, content of hydrogen peroxide initial in the reaction system is lower, so oxidative degradation is carried out very slowly, the temperature that must take the mode of heating in water bath to keep reaction system makes DeR continue to carry out.(2) patent No. is that 02135410.3 Chinese patent has been announced a kind of normal temperature oxidation degradation method, specifically is that chitosan is added in the acid solution, adds H again
2O
2With FeSO
4Mixed solution, stirring reaction under the normal temperature.The subject matter that this method exists is to have added Fe
2+, be difficult to remove; And this method is only prepared the above low molecular chitosan of molecular weight 3000 dalton, and fails to prepare oligochitosan.(3) in publication number is the patent application of CN1602891A the method that a kind of oxidative degradation prepares the chitosan oligomer oral liquid is disclosed, it is this that method is simple, but need to adopt outer heating to control and keep temperature of reaction system, 40～60 ℃ of reaction needed 12 hours, 95～110 ℃ of reaction needed 0.5～2 hour.This method low-temp reaction needs for a long time, and pyroreaction then can produce coloured by product.(4) patent No. is that 200410020831.1 Chinese patent has been announced a kind of method for preparing the chitin oligosaccharide compound.This method need adopt outer heating to keep temperature of reaction system; Reaction is successively carried out under acidity, alkaline condition, and is consuming time longer; The amount of the acid of using in the reaction system is a lot, and product colour can be darker, can be higher with saltiness in the product of in the alkali and back; Products obtained therefrom need carry out aftertreatments such as ethanol sedimentation, and technology is comparatively complicated, and production cost is higher; Fail to prepare molecular weight less than 2000 daltonian oligochitosans.(5) number of patent application is the preparation method that the Chinese patent of CN200510009669.8 has been announced a kind of water-soluble chitosan oligosaccharide.This method needs outer heating to keep temperature of reaction system at 60～80 ℃; Introduced the Na ion in the reaction, separation difficulty; The hydrogen peroxide that adds in the reaction is disposable adding, and the amount that adds is bigger, and chitosan: the weight ratio of hydrogen peroxide is 1: 2～4, causes the reaction product molecular-weight average too low, is 609 dalton, causes the medicinal physiologically active of its product relatively poor.
In sum, utilize various oxidation degradation methods that chitosan is handled in the existing Chinese patent, can make its degraded, but at present, most degradation method also just is in the laboratory study stage, has such or such deficiency.To really prepare oligochitosan and final industrial large-scale production, the generation significant social economic benefit of realizing, also must carry out more deep research at aspects such as the separation of the molecular weight distribution of its mechanism of degradation, degradation efficiency, degraded product, degraded product, purifying, and explore new environmental protection, safety, economically viable degradation method, develop new production technique.
Summary of the invention
The object of the present invention is to provide and a kind ofly utilize reaction make reaction system maintain the preparation method that low optimal temperature is carried out oxidative degradation, products obtained therefrom is light yellow, sense organ is good oligochitosan from heating up, and present method environmental protection, safety, economically feasible, the degraded product narrow molecular weight distribution, monose and molecular weight are 10, chitosan more than 000 dalton is few, and effective polysaccharide content height of high physiologically active is water-soluble fully, need not separate, purifying, be convenient to realize industrialization production and application.
In order to the technical scheme that realizes the object of the invention be, a kind ofly utilize reaction to make reaction system maintain low optimal temperature from heating up to carry out the method that oxidative degradation prepares oligochitosan that its operation steps is:
(1) earlier the water in the reaction vessel is warming up to 25～60 ℃, adds macromolecule chitosan raw material in the entry then and stir evenly, the mass concentration of chitosan is 8～30%.Wherein the macromolecule chitosan is meant that molecular-weight average is at 100,000 dalton to 100, ten thousand daltonian chitosans.
(2) add aqueous hydrogen peroxide solution and stirring evenly in reaction vessel, wherein the mass concentration of pure hydrogen peroxide is 10～50% in the aqueous hydrogen peroxide solution.
(3) add Glacial acetic acid and stirring evenly again in reaction vessel, the add-on of Glacial acetic acid should make the pH value of reaction system be controlled at 6～7, and DeR promptly begins subsequently.Carry out adding aqueous hydrogen peroxide solution again in the process in reaction, wherein aqueous hydrogen peroxide solution is that gradation adds, more than in steps the accumulation add-on of pure hydrogen peroxide be 0.5～1.0 times of chitosan mass.Finish through reaction in about 2 hours, obtain the homogeneous aqueous solution of oligochitosan.
(4) directly or carry out spraying drying, vacuum-drying or frost drying after concentrating and to obtain light yellow oligochitosan powder with the aqueous solution.
The method that the present invention takes elder generation that water is heated up after stirring evenly in the water after macromolecule chitosan, hydrogen peroxide and the Glacial acetic acid adding intensification, promptly begins to take place the oxidative degradation thermopositive reaction.The liberated heat of reaction own just is enough to keep the optimal temperature of material, makes reaction steadily to carry out, and can not rise to comparatively high temps again and cause producing by product.
Mostly be to adopt once to add hydrogen peroxide in the prior art, such operation is unfavorable for that stable reaction ground carries out, harsh requirement has been proposed for reaction unit in the actual production or others, simultaneously the ratio of high physiologically active oligochitosan in product not high (being generally about 10～20%).The present invention's gradation in different operation stepss adds hydrogen peroxide, in conjunction with operation before to the water heating, realized the self-warming up oxidative degradation reaction of system, a large amount of generations of by product have not only been avoided in such operation, the more important thing is and have improved the ratio (ratio reaches more than 60%) of high physiologically active oligochitosan in the product.
With Glacial acetic acid the pH value of the mixed material of chitosan and hydrogen peroxide is adjusted to 6～7, can make speed of response all compare from start to finish evenly, easily control, and prevented because the low excessively product colour that causes of the pH of initial reaction system is dark, the phenomenon of sense organ difference, the finished product have pale yellow color and luster, and sense organ is better.
Method of the present invention can be prepared molecular-weight average and be lower than 2000 daltonian light yellow oligochitosans.
Embodiment
Below by embodiment the present invention is described in more detail.
Embodiment 1.
1. 7 kilograms water is joined in the reaction vessel, heating makes water be warming up to 30 ℃; Be that 450,000 daltonian chitosan 2Kg join in the container then with molecular weight, stir, make the raw material homogeneous immersion.
2. hydrogen peroxide (mass concentration the is 35%) aqueous solution with 1.5Kg joins in the chitosan infiltrate, and mixes.At this moment, the mass concentration of chitosan is 19% in the mixture, and the mass concentration of hydrogen peroxide is 5%.
3. immediately add the 100ml Glacial acetic acid in above-mentioned mixing solutions, and stir evenly, obtain the pH value of mixture this moment between 6～7.
4. after above-mentioned material added, DeR promptly began to carry out, and material also slowly heats up thereupon.After reaction was carried out 50 minutes, hydrogen peroxide (mass concentration the is 35%) aqueous solution with 0.5Kg added in the material again, and mixes.
5. after reaction was carried out 20 minutes again, hydrogen peroxide (mass concentration the is 35%) aqueous solution with 0.5Kg added in the material again, and mixes.
6. the operation of repeating step 5 once.React again and can obtain the uniform oligochitosan aqueous solution in 30 minutes.At this moment, total add-on of pure hydrogen peroxide is 1.05Kg, with the mass ratio of chitosan raw material be 0.525: 1; Reaction times is 2 hours.
7. measuring the oligochitosan aqueous temperature, is 80 ℃.
8. sampling, the oven dry back adopts high-efficient liquid phase technique to measure the molecular-weight average and the distribution thereof of oligochitosan, and molecular-weight average is 1670 dalton.
Table 1:
Oligochitosan molecular weight product (unit: dalton) distribute
| Molecular weight | ＞10000 | 10000～5000 | 5000～3000 | 3000～2000 | ＜2000 |
| Ratio % | 0 | 2.23 | 10.62 | 17.87 | 69.28 |
Embodiment 2.
1. 7 kilograms water is joined in the reaction vessel, heating makes water be warming up to 60 ℃; Be that 450,000 daltonian chitosan 2Kg join in the container then with molecular weight, stir, make the raw material homogeneous immersion.
2. hydrogen peroxide (mass concentration the is 35%) aqueous solution with 1.0Kg joins in the chitosan infiltrate, and mixes.At this moment, the mass concentration of chitosan is 20% in the mixture, and the mass concentration of hydrogen peroxide is 3.5%.
3. immediately add the 100ml Glacial acetic acid in above-mentioned mixing solutions, and stir evenly, obtain the pH value of mixture this moment between 6～7.
4. after above-mentioned material added, DeR promptly began to carry out, and material also slowly heats up thereupon.After reaction was carried out 30 minutes, hydrogen peroxide (mass concentration the is 35%) aqueous solution with 1Kg added in the material again, and mixes.
5. after reaction was carried out 30 minutes again, hydrogen peroxide (mass concentration the is 35%) aqueous solution with 1Kg added in the material again, and mixes.
6. the operation of repeating step 5 once.React again and can obtain the uniform oligochitosan aqueous solution in 30 minutes.At this moment, total add-on of pure hydrogen peroxide is 1.4Kg, with the mass ratio of chitosan raw material be 0.7: 1; Reaction times is about 2 hours.
7. measuring the oligochitosan aqueous temperature, is 85 ℃.
8. sampling, the oven dry back adopts high-efficient liquid phase technique to measure the molecular-weight average and the distribution thereof of oligochitosan, and molecular-weight average is 1124 dalton.
Table 2:
Oligochitosan molecular weight product (unit: dalton) distribute
| Molecular weight | ＞10000 | 10000～5000 | 5000～3000 | 3000～2000 | ＜2000 |
| Ratio % | 0 | 1.04 | 5.19 | 10.76 | 83.01 |
The reaction times of present method is determined according to real reaction situations such as charging capacitys.Under the situation of and equal quality product identical in charging capacity, reaction times of present method and technology of preparing obviously are better than method of the prior art.
Claims (10)
1. method for preparing oligochitosan, it comprises:
(1) earlier the water in the reaction vessel is heated up, then macromolecule chitosan raw material is added in the entry;
(2) in reaction vessel, add aqueous hydrogen peroxide solution;
(3) add acid again in reaction vessel, DeR begins immediately, carries out adding aqueous hydrogen peroxide solution again in the process in reaction, after reaction finishes, promptly obtains the homogeneous aqueous solution of oligochitosan;
(4) directly or carry out spraying drying, vacuum-drying or frost drying after concentrating and to obtain molecular-weight average less than 2000 daltonian light yellow oligochitosan powders with the aqueous solution;
Above-mentioned macromolecule chitosan raw material is meant that molecular-weight average is at 100,000 dalton to 100, ten thousand daltonian chitosans;
Add aqueous hydrogen peroxide solution in above-mentioned (3), be meant that gradation adds.
2. the method for preparing oligochitosan as claimed in claim 1 is characterized in that: in the first step, earlier the water in the reaction vessel is warming up to 25～60 ℃.
3. the method for preparing oligochitosan as claimed in claim 1 is characterized in that: in the first step, adding macromolecule chitosan raw material also stirs evenly, and the mass concentration of chitosan is 8～30%.
4. as the said method for preparing oligochitosan of claim 1, it is characterized in that: the adding aqueous hydrogen peroxide solution also stirs evenly, wherein the mass concentration of pure hydrogen peroxide is 10～50% in the aqueous hydrogen peroxide solution, and the accumulation add-on of pure hydrogen peroxide is 0.5～1 times of chitosan mass.
5. as the said method for preparing oligochitosan of claim 1, it is characterized in that: in the 3rd step, the acid that is added is mineral acid and/or organic acid.
6. as the said method for preparing oligochitosan of claim 5, it is characterized in that: described mineral acid is selected from one or more in hydrochloric acid, nitric acid and the sulfuric acid.
7. as the said method for preparing oligochitosan of claim 5, it is characterized in that: described organic acid selects one or more in light-coloured vinegar acid, citric acid and the lactic acid.
8. as the said method for preparing oligochitosan of claim 5～7, it is characterized in that: the add-on of acid should make the pH value of reaction system be controlled at 6～7.
9. method for preparing oligochitosan, it comprises as follows:
(1) 7 kilograms water is joined in the reaction vessel, heating makes water be warming up to 30 ℃, is that 450,000 daltonian chitosan 2Kg join in the container then with molecular-weight average, stirs, and makes the raw material homogeneous immersion;
(2) hydrogen peroxide (mass concentration the is 35%) aqueous solution with 1.5Kg joins in the chitosan infiltrate, and mixes, and at this moment, the mass concentration of chitosan is 19% in the mixture, and the mass concentration of hydrogen peroxide is 5%;
(3) immediately add the 100ml Glacial acetic acid in above-mentioned mixing solutions, and stir evenly, obtain the pH value of mixture this moment between 6～7;
(4) after above-mentioned material added, DeR promptly began to carry out, and material also slowly heats up thereupon, and after reaction was carried out 50 minutes, hydrogen peroxide (mass concentration the is 35%) aqueous solution with 0.5Kg added in the material again, and mixes;
(5) after reaction was carried out 20 minutes again, hydrogen peroxide (mass concentration the is 35%) aqueous solution with 0.5Kg added in the material again, and mixes;
(6) operation of repeating step 5 is once reacted and can be obtained the uniform oligochitosan aqueous solution in 30 minutes, and at this moment, total add-on of pure hydrogen peroxide is 1.05Kg, with the mass ratio of chitosan raw material be 0.525: 1; Reaction times is 2 hours;
(7) measuring the oligochitosan aqueous temperature, is 80 ℃;
(8) sampling, the oven dry back adopts high-efficient liquid phase technique to measure the molecular-weight average and the distribution thereof of oligochitosan, promptly obtains product.
10. method for preparing oligochitosan, it comprises as follows:
(1) 7 kilograms water is joined in the reaction vessel, heating makes water be warming up to 60 ℃, is that 450,000 daltonian chitosan 2Kg join in the container then with molecular-weight average, stirs, and makes the raw material homogeneous immersion;
(2) hydrogen peroxide (mass concentration the is 35%) aqueous solution with 1.0Kg joins in the chitosan infiltrate, and mixes, and at this moment, the mass concentration of chitosan is 20% in the mixture, and the mass concentration of hydrogen peroxide is 3.5%;
(3) immediately add the 100ml Glacial acetic acid in above-mentioned mixing solutions, and stir evenly, obtain the pH value of mixture this moment between 6～7;
(4) after above-mentioned material added, DeR promptly began to carry out, and material also slowly heats up thereupon, and after reaction was carried out 30 minutes, hydrogen peroxide (mass concentration the is 35%) aqueous solution with 1Kg added in the material again, and mixes;
(5) after reaction was carried out 30 minutes again, hydrogen peroxide (mass concentration the is 35%) aqueous solution with 1Kg added in the material again, and mixes;
(6) operation of repeating step 5 is once reacted and can be obtained the uniform oligochitosan aqueous solution in 30 minutes, and at this moment, total add-on of pure hydrogen peroxide is 1.4Kg, with the mass ratio of chitosan raw material be 0.7: 1; Reaction times is 2 hours;
(7) measuring the oligochitosan aqueous temperature, is 85 ℃;
(8) sampling, the oven dry back adopts high-efficient liquid phase technique to measure the molecular-weight average and the distribution thereof of oligochitosan, promptly obtains product.
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103435717A (en) * | 2013-08-16 | 2013-12-11 | 江苏顺心德生物科技有限公司 | Chitosan oligosaccharide |
| CN104045742A (en) * | 2014-06-19 | 2014-09-17 | 广西大学 | Carboxyl-containing chitosan oligosaccharide-rare earth nitrate complex and application thereof |
| CN112159283A (en) * | 2020-10-18 | 2021-01-01 | 山东喜美农业科技有限公司 | Preparation and use methods of chitosan oligosaccharide coated slow-release fertilizer |
| CN112175143A (en) * | 2020-10-18 | 2021-01-05 | 山东喜美农业科技有限公司 | Preparation method of chitosan oligosaccharide coated sustained release agent |
-
2008
- 2008-01-30 CN CNA2008100066408A patent/CN101220061A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103435717A (en) * | 2013-08-16 | 2013-12-11 | 江苏顺心德生物科技有限公司 | Chitosan oligosaccharide |
| CN103435717B (en) * | 2013-08-16 | 2014-06-25 | 江苏顺心德生物科技有限公司 | Chitosan oligosaccharide |
| CN104045742A (en) * | 2014-06-19 | 2014-09-17 | 广西大学 | Carboxyl-containing chitosan oligosaccharide-rare earth nitrate complex and application thereof |
| CN112159283A (en) * | 2020-10-18 | 2021-01-01 | 山东喜美农业科技有限公司 | Preparation and use methods of chitosan oligosaccharide coated slow-release fertilizer |
| CN112175143A (en) * | 2020-10-18 | 2021-01-05 | 山东喜美农业科技有限公司 | Preparation method of chitosan oligosaccharide coated sustained release agent |
| CN112175143B (en) * | 2020-10-18 | 2022-03-29 | 山东喜美农业科技有限公司 | Preparation method of chitosan oligosaccharide coated sustained release agent |
| CN112159283B (en) * | 2020-10-18 | 2022-05-13 | 史丹利化肥（平原）有限公司 | Preparation and use methods of chitosan oligosaccharide coated slow-release fertilizer |
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