CN102766225A - Preparation method of peritosan polysulfate sodium and xylooligosaccharide - Google Patents

Abstract

The invention discloses a preparation method of xylo-oligosaccharide, which comprises the following steps: (1) in an aqueous alkali solution, oxidizing and depolymerizing xylan with hydrogen peroxide; (2) step (1) After the reaction, adjust the pH of the reaction solution to 4-7, add C ₁ to C ₄ fatty alcohol to the reaction solution, and precipitate a white solid to obtain xylo-oligosaccharide; the weight-average molecular weight of xylo-oligosaccharide is 2000-4000; wherein, the aqueous alkali solution is an aqueous solution of alkaline earth metal and/or alkali metal hydroxide, the concentration of alkali is 1 mg/ml-40 mg/ml; the mass ratio of alkali to xylan is 0.01-0.4; The mass ratio of hydrogen peroxide to xylan is 0.03:1-0.3:1; the temperature of oxidative depolymerization reaction is 80° C. to reflux temperature. The preparation method of the present invention is different from the prior art, and has simple operation and easy purification, is suitable for industrialization, and does not cause the problem of reduced sulfate content.

Description

A kind of preparation method of sodium pentosan polysulfate and a kind of xylooligosaccharide

technical field

The invention specifically relates to a preparation method of pentosan polysulfate sodium and a kind of xylooligosaccharide.

Background technique

该产品尚未在中国大陆上市。The molecular weight range of pentosan polysulfate sodium [37319-17-8] is 4000-6000 (structural formula 2), is a kind of medicine for the treatment of kidney infection, interstitial cystitis and tumor, produced by Ortho McNeil Company, trade name for

The product is not yet available in mainland China.

Structural formula 2

Sodium pentosan polysulfate is a semi-synthetic heparin-like macromolecular carbohydrate. It is a white, odorless powder with weak hygroscopicity and soluble in water.

The known sodium pentosan polysulfate is based on xylan (which can be extracted from bark) as a raw material, through four steps of operation: the first step into sulfuric acid ester, the second step into sodium salt, the third step of depolymerization, The fourth step is separation and purification.

The patent US2689848 mentions that xylan is operated in the following four steps: the first step is to prepare xylan sulfate with the participation of chlorosulfonic acid in pyridine; the second step is to react with sodium hydroxide in a mixed solvent of methanol and water, Sodium xylan polysulfate is prepared; the third step is oxidative depolymerization in acidic or neutral aqueous solution to obtain depolymerization products; the fourth step is desalination of depolymerization products by dialysis, fractional sedimentation, and filtration to obtain a patent The target product mentioned in. The Z _η value of the target product is between 0.0030 and 0.015, and the sulfur content is between 13.5 and 17%.

However, the content of this patent does not relate to the specific molecular weight of its target product, and it also has the following disadvantages: 1. The operation is cumbersome, the cost is high, and the yield is low; Inconvenient filtering operation; 3. Dialysis membrane is used in the fourth step of purification, which cannot be adapted to industrial production.

Patent WO2009/087581 optimized the above process: in the first step of sulfation of xylose, picolin (α, β, γ-picoline was used respectively) was used instead of pyridine, which improved the yield; In the second step of sodium salt formation, pure methanol is used as a solvent to reduce the difficulty of post-processing; in the fourth step of separation and purification, a nanofiltration membrane system is used to obtain a product with a molecular weight of 4000-6000.

There are still the following problems in the prior art: 1. In order to obtain the product with the target molecular weight of 4000-6000, it is necessary to pass more cumbersome purification means, such as US2689848 adopts the method of fractional sedimentation, and WO2009/087581 adopts the nanofiltration membrane system. 2. The operation of oxidative depolymerization is carried out in the stage of pentosan polysulfate sodium. Due to the instability of sulfate radical, side reactions of desulfation radical are prone to occur, resulting in the problem of the decrease of the degree of sulfation. In order to avoid the sulfation degree decreasing too much and affecting the drug efficacy, the depolymerization time must be strictly controlled, which in turn leads to incomplete degradation of the polysaccharide chain, making the yield of the target product with a molecular weight of 4000-6000 too low. (The yields of the depolymerization steps of US2689848 are all less than 50%, and the yields of the depolymerization steps of WO2009/087581 are all less than 55%).

Contents of the invention

The technical problem to be solved by the present invention is in order to overcome in the existing preparation method of pentosan polysulfate sodium, the operation is loaded down with trivial details, and cost is high, and productive rate is low, and the defect such as sulfate radical content reduces during depolymerization, and provides a kind of pentosan polysulfate A preparation method of polysaccharide polysulfate sodium and a kind of xylooligosaccharide. The present invention directly oxidizes and depolymerizes xylan, and can realize controllable and sufficient depolymerization because there is no side reaction such as desulfation; thereby obtaining high-yield, uniform molecular weight distribution and satisfactory xylo-oligosaccharides; It undergoes sulfation to give the desired product. Therefore, the preparation method of the present invention is completely different from the prior art, and is simple to operate, easy to purify, suitable for industrialization, and does not cause the problem of reduced sulfate content.

At first, the present invention relates to a kind of preparation method of xylo-oligosaccharide, it comprises the following steps:

(1) In an aqueous alkali solution, the xylan is subjected to an oxidative depolymerization reaction with hydrogen peroxide;

(2) After the reaction in step (1), adjust the pH of the reaction solution to 4-7, add C ₁ to C ₄ fatty alcohol to the reaction solution, and precipitate a white solid to obtain xylo-oligosaccharide; The weight-average molecular weight of xylo-oligosaccharide is 2000-4000;

Wherein, the aqueous solution of alkali is the aqueous solution of the hydroxide of alkaline earth metal and/or alkali metal, and the concentration of alkali is 1mg/ml～40mg/ml; The mass ratio of alkali and xylan is 0.01～0.4; Hydrogen peroxide and xylan The mass ratio of the polysaccharide is 0.03:1-0.3:1; the temperature of the oxidative depolymerization reaction is 80° C. to reflux temperature.

In step (1), in the aqueous alkali solution, the concentration of the alkali is preferably 10 mg/ml-20 mg/ml. The temperature of the oxidative depolymerization reaction is preferably from 95° C. to reflux temperature. The C ₁ -C ₄ fatty alcohol is preferably methanol or ethanol. The mass ratio of hydrogen peroxide and xylan is preferably 0.09:1-0.18:1. The hydrogen peroxide is pure hydrogen peroxide in solution. Generally speaking, hydrogen peroxide participates in the reaction in the form of aqueous solution, and its mass concentration is preferably 20%-40%, more preferably 30%. In the aqueous alkali solution, the alkaline earth metal and/or alkali metal hydroxide is preferably sodium hydroxide and/or potassium hydroxide. The mass ratio of alkali and xylan is preferably 0.1-0.25. The xylan described above can be conventional xylan in the field, and its weight average molecular weight is preferably 10000-40000. The oxidative depolymerization reaction generally takes 20 minutes to 2 hours to stop the reaction, and the product quality is confirmed by conventional methods in the field.

In step (1), preferably, first xylan is added in the aqueous solution of alkali, becomes the suspension liquid of partial dissolution, adds the aqueous hydrogen peroxide solution of mass concentration 20%～40% (preferably 30%), at 80 ℃ to reflux temperature for the reaction.

In step (2), preferably, before adding the C ₁ -C ₄ fatty alcohol, it is cooled first, and then the pH of the reaction solution is adjusted to 4-7 (preferably 4-6, more preferably 5). The pH adjustment method described in step (2) can be a conventional pH adjustment method in the art, such as adding dilute acid aqueous solution for adjustment.

In step (2), the added volume of the C ₁ -C ₄ fatty alcohol is until the white solid is no longer precipitated, preferably 3-8 times the volume of the reaction solution.

The present invention further relates to the xylo-oligosaccharide prepared by the above preparation method.

The present invention also relates to a preparation method of sodium pentosan polysulfate, which comprises the following steps: performing a sulfonate ester reaction and a salt formation reaction on the above-mentioned xylooligosaccharide.

Wherein, the method and the condition of the described reaction of forming sulfonate can be the conventional method and condition of preparing pentosan polysulfonate in this field, and the following method is preferred in the present invention: under the action of alkali, the above-mentioned oligosaccharide The polyxylose reacts with chlorosulfonic acid and/or pyridine sulfur trioxide to form a sulfonate ester.

Wherein, the base is preferably one or more of pyridine, α-picoline, β-picoline and γ-picoline. The amount of alkali used is preferably 2-10 times, preferably 5-10 times, the mass of xylo-oligosaccharide. The dosage of the chlorosulfonic acid and/or pyridine sulfur trioxide is preferably 3-6 times the mass of xylo-oligosaccharide. The temperature of the reaction to form sulfonate is preferably 60-80°C. The reaction to form a sulfonate ester can be terminated after confirming the quality of the product according to conventional methods in the art, generally within 2 to 24 hours, preferably within 3 to 10 hours.

In the present invention, the method and condition of described salt-forming reaction all can be the conventional method and condition in the salt-forming reaction of pentosan polysulfate sodium prepared in this area, and the present invention preferably following method: will become sulfonate ester reaction system The obtained product is subjected to a salt-forming reaction with a water-alcohol mixed solution of alkali, and then the inorganic salt is removed by dialysis, then concentrated to a suitable volume, dropped into alcohol for crystallization, and a product with a weight average molecular weight of 4000-6000 is obtained. Wherein, the alkali in the described salt-forming reaction is preferably one or more of sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate and potassium bicarbonate, more preferably hydrogen Sodium Oxide and/or Potassium Hydroxide.

On the basis of conforming to common knowledge in the field, the above-mentioned preferred conditions can be combined arbitrarily to obtain preferred examples of the present invention.

The reagents and raw materials used in the present invention are all commercially available.

The positive and progressive effect of the present invention is that: the present invention adopts the method of oxidizing and depolymerizing under alkaline conditions and then forming sulfonate to prepare polypentose polysulfonate and its salt, that is, the target molecular weight of 4000-6000 can be obtained. products, avoiding complex purification methods. Moreover, the problem of reducing the content of sulfate radicals produced during the first sulfonation and then depolymerization is avoided. Moreover, the invention has simple and convenient operation and low cost, and can meet the needs of industrialized production.

Detailed ways

The present invention is further illustrated below by means of examples, but the present invention is not limited to the scope of the examples. For the experimental methods that do not specify specific conditions in the following examples, select according to conventional methods and conditions, or according to the product instructions.

In each of the following examples:

The identification method of xylo-oligosaccharides, that is, gel filtration method, can refer to the literature: "Chemistry and Pharmacology of Traditional Chinese Medicine Polysaccharides" Ji Yubin, People's Health Publishing House, the method is briefly described as follows: SephadexG-75 column, 0.2M NaCl aqueous solution After elution, the molecular weight of xylo-oligosaccharide was measured to be 2000-4000.

The weight average molecular weight of the raw material xylan is 30000.

The pentosan polysulfate sodium that makes at last is by capillary electrophoresis method, and fingerprint spectrogram is consistent with standard product, and gel filtration method measures molecular weight at 4000～6000, and elemental analysis measures sulfur content 15～17.5%, proves that the product obtained is consistent with Elmiron standards are consistent. References for detection and identification methods: Arch.Pharm.Pharm.Med.Chem.2001, 334, 27-29.

Example 1

Add 10g xylan to 100mL 1mg/mL sodium hydroxide aqueous solution, stir at 80°C to become a suspension; add 1.5mL 20% hydrogen peroxide solution, and react at 80°C for 2 hours; Hydrochloric acid was used to adjust the pH to 4; 300 mL of methanol was added, and a white solid precipitated out. Filter and dry in vacuo to obtain 6.2 g of white solid. The yield is 62%, and the molecular weight of xylo-oligosaccharide measured by gel filtration method is 2000-4000.

Add 25mL of pyridine to the above 6.2g of white solid; stir and heat to 60°C, then slowly add 20g of sulfur trioxide pyridine to the reaction system while vigorously stirring; after the addition of sulfur trioxide and pyridine is completed, keep the reaction at 60°C for 2 hours After the reaction is completed, the system is poured into 125mL of methanol, while vigorously stirring to obtain a yellowish solid; after filtration, the filter cake is dissolved in 20mL of water, and then dripped into a mixed solvent of 250mL of methanol and 13mL of 33% aqueous sodium hydroxide solution , stirring continuously; after the reaction, add acetic acid dropwise to the system to pH = 6 to obtain a white solid; filter, wash the filter cake with methanol, acetone and ether respectively; finally dissolve the filter cake in water, and treat it with a dialysis membrane to remove Inorganic salt; concentrated to 50 ml, dropped into 150 ml of ethanol, filtered to collect the white solid, dried in vacuo to obtain 10.3 g of the target product. The molecular weight of pentosan polysulfate sodium measured by gel filtration method is 4000-6000, and the S content of elemental analysis is 17.2%.

Example 2

Add 10g xylan to 135mL 15mg/mL sodium hydroxide aqueous solution, stir at 80°C to become a suspension; add 3.7mL 30% hydrogen peroxide solution, and reflux for 1.5 hours; Adjust the pH to 5; add 600 mL of ethanol, and a white solid precipitates out. Filter and dry in vacuo to obtain 7.8 g of white solid. The yield is 78%, and the molecular weight of the xylo-oligosaccharide measured by gel filtration method is 2000-4000.

Add 40mL of γ-picoline to the above 7.8g of white solid; stir and heat to 60°C, slowly add 40g of pyridine sulfur trioxide to the reaction system while vigorously stirring; after adding pyridine sulfur trioxide, heat up to React at 80°C for 4 hours; after the reaction is completed, pour the system into 200mL of methanol and stir vigorously at the same time to obtain a yellowish solid; after filtering, dissolve the filter cake in 30mL of water, and then drop into 400mL of methanol and 20mL of 33% sodium hydroxide In the mixed solvent of the aqueous solution, stir continuously; after the reaction is completed, add acetic acid dropwise to the system to pH = 6 to obtain a white solid; filter, wash the filter cake with methanol, acetone and ether respectively; finally dissolve the filter cake in water, after Dialysis membrane treatment, removal of inorganic salts; concentration to 270 ml, dropwise into 800 ml of ethanol, filtration to collect white solid, vacuum drying to obtain 11.2 g of the target product. The molecular weight of pentosan polysulfate sodium is 4000-6000 as measured by gel filtration method, and the S content of elemental analysis is 16.2%.

Example 3

Add 10g xylan to 50mL 40mg/mL aqueous sodium hydroxide solution, stir at 80°C to become a suspension; add 9mL 40% hydrogen peroxide solution, and react at 95°C for 1.5 hours; Adjust the pH to 5; add 400 mL of propanol, and a white solid precipitates out. Filter and dry in vacuo to obtain 5.3 g of white solid. The yield is 53%, and the molecular weight of xylo-oligosaccharide measured by gel filtration method is 2000-4000.

Add 50mL of α-picoline to the above 5.3g of white solid; stir and heat to 60°C, slowly add 32g of pyridine sulfur trioxide to the reaction system while stirring vigorously; React at 60°C for 6 hours; after the reaction, pour the system into 270mL of methanol and stir vigorously at the same time to obtain a yellowish solid; after filtering, dissolve the filter cake in 40mL of water, and then drop into 500mL of methanol and 25mL of 33% sodium hydroxide In the mixed solvent of the aqueous solution, stir continuously; after the reaction is completed, add acetic acid dropwise to the system to pH = 6 to obtain a white solid; filter, wash the filter cake with methanol, acetone and ether respectively; finally dissolve the filter cake in water, after Dialysis membrane treatment, removal of inorganic salts; concentration to 270 ml, dropwise into 800 ml of ethanol, filtration to collect white solid, vacuum drying to obtain 8.5 g of the target product. The molecular weight of pentosan polysulfate sodium is 4000-6000 as measured by gel filtration method, and the S content of elemental analysis is 16.4%.

Example 4

Add 10g xylan to 100mL 40mg/mL sodium hydroxide aqueous solution, stir at 80°C to become a suspension; add 3mL 40% hydrogen peroxide solution, keep at 80°C for 20 minutes; Adjust the pH to 6 with hydrochloric acid; add 400 mL of butanol, and a white solid precipitates out. Filter and dry in vacuo to obtain 7g of white solid. The yield is 70%, and the molecular weight of the xylo-oligosaccharide is 2000-4000 as measured by the gel filtration method.

Measure 21mL of chlorosulfonic acid, slowly add it to 60mL of pyridine, and control the temperature below 40°C; after the dropwise addition, raise the temperature of the system to 60°C, and add 7g of the product prepared above; after the addition, raise the temperature to 80°C React for 12 hours; after the reaction is complete, pour the system into 280mL of methanol and stir vigorously at the same time to obtain a slightly yellow solid; Stir continuously in the mixed solvent; after the reaction is completed, add acetic acid dropwise to the system to pH = 6 to obtain a white solid; filter and wash the filter cake with methanol, acetone and ether respectively; finally dissolve the filter cake in water and pass through the dialysis membrane treatment to remove inorganic salts; concentrate to 120 ml, drop into 360 ml of ethanol, collect the white solid by filtration, and dry in vacuo to obtain 9.3 g of the target product. The molecular weight of xylo-oligosaccharide measured by gel filtration method is 4000-6000, and the S content of elemental analysis is 15.3%.

Example 5

Add 10g xylan to 135mL 15mg/mL potassium hydroxide aqueous solution, stir at 80°C to become a suspension; add 3.7mL 30% hydrogen peroxide solution, and reflux for 20 minutes; Adjust the pH to 4; add 500 mL of methanol, and a white solid precipitates out. Filter and dry in vacuo to obtain 7.2 g of white solid. The yield is 72%, and the molecular weight of the xylo-oligosaccharide is 2000-4000 as measured by the gel filtration method.

Add 15mL of pyridine to the above 7.2g of white solid; stir and heat to 60°C, slowly add 29g of pyridine sulfur trioxide to the reaction system while vigorously stirring; after adding pyridine sulfur trioxide, heat up to 80°C to react 6 hour; after the reaction was completed, the system was poured into 70mL of methanol, while vigorously stirring to obtain a yellowish solid; after filtration, the filter cake was dissolved in 12mL of water, and then dripped into a mixed solvent of 140mL of methanol and 8mL of 33% aqueous sodium hydroxide solution During the process, stir continuously; after the reaction is completed, add acetic acid dropwise to the system to pH = 6 to obtain a white solid; filter and wash the filter cake with methanol, acetone and ether respectively; finally dissolve the filter cake in water and treat it with a dialysis membrane. Remove inorganic salts; concentrate to 30 ml, drop into 100 ml of ethanol, collect the white solid by filtration, and dry in vacuo to obtain 11.3 g of the target product. The molecular weight of pentosan polysulfate sodium measured by gel filtration method is 4000-6000, and the S content of elemental analysis is 17.1%.

Example 6

Add 10g of xylan to 135mL of 15mg/mL potassium hydroxide aqueous solution, stir at 80°C to become a suspension; add 11mL of 30% hydrogen peroxide solution, and reflux for 20 minutes; quickly cool in an ice-water bath, and adjust with 1mol/L hydrochloric acid pH=6; 600mL of ethanol was added, and a white solid was precipitated. Filter and dry in vacuo to obtain 7.6 g of white solid. The yield is 76%, and the molecular weight of the xylo-oligosaccharide is 2000-4000 as measured by the gel filtration method.

Add 40mL of γ-picoline to the above 7.6g of white solid; stir and heat to 60°C, slowly add 38g of pyridine sulfur trioxide to the reaction system while stirring vigorously; React at 60°C for 12 hours; after the reaction, pour the system into 190mL of methanol and stir vigorously at the same time to obtain a yellowish solid; after filtering, dissolve the filter cake in 30mL of water, and then drop into 380mL of methanol and 19mL of 33% sodium hydroxide In the mixed solvent of the aqueous solution, stir continuously; after the reaction is completed, add acetic acid dropwise to the system to pH = 6 to obtain a white solid; filter, wash the filter cake with methanol, acetone and ether respectively; finally dissolve the filter cake in water, after Dialyzed membrane treatment to remove inorganic salts; concentrated to 80 ml, dropped into 240 ml of ethanol, filtered to collect white solid, vacuum dried to obtain 11.9 g of the target product. The molecular weight of pentosan polysulfate sodium measured by gel filtration method is 4000-6000, and the S content of elemental analysis is 17.2%.

Example 7

Add 10g xylan to 100mL 40mg/mL potassium hydroxide aqueous solution, stir at 80°C to become a suspension; add 9mL 40% hydrogen peroxide solution, and reflux for 1.5 hours; cool rapidly in an ice-water bath, and adjust with 1mol/L hydrochloric acid pH=4; 600 mL of propanol was added, and a white solid precipitated out. Filter and dry in vacuo to obtain 6.3 g of white solid. The yield is 63%, and the molecular weight of xylo-oligosaccharide measured by gel filtration method is 2000-4000.

Add 60mL of β-picoline to the above 6.3g white solid; stir and heat to 60°C, slowly add 19g of pyridine sulfur trioxide to the reaction system while vigorously stirring; after adding pyridine sulfur trioxide, heat up to React at 80°C for 4 hours; after the reaction, pour the system into 320mL of methanol and stir vigorously at the same time to obtain a yellowish solid; after filtering, dissolve the filter cake in 50mL of water, and then drop into 630mL of methanol and 32mL of 33% sodium hydroxide In the mixed solvent of the aqueous solution, stir continuously; after the reaction is completed, add acetic acid dropwise to the system to pH = 6 to obtain a white solid; filter, wash the filter cake with methanol, acetone and ether respectively; finally dissolve the filter cake in water, after Dialyzed membrane treatment to remove inorganic salts; concentrated to 120 ml, dropped into 360 ml of ethanol, filtered to collect white solid, vacuum dried to obtain 9.5 g of the target product. The molecular weight of pentosan polysulfate sodium is 4000-6000 as measured by gel filtration method, and the S content of elemental analysis is 16.5%.

Example 8

Add 10g xylan to 100mL 1mg/mL potassium hydroxide aqueous solution, stir at 80°C to become a suspension; add 5.3mL 20% hydrogen peroxide solution, and reflux for 2 hours; Adjust the pH to 5; add 600 mL of propanol, and a white solid precipitates out. Filter and dry in vacuo to obtain 6.2 g of white solid. The yield is 62%, and the molecular weight of xylo-oligosaccharide measured by gel filtration method is 2000-4000.

Measure 25mL of chlorosulfonic acid, slowly add it to 65mL α-picoline, control the temperature below 40°C; after the dropwise addition, raise the temperature of the system to 60°C, and add 6.2g of the product prepared above; , heated to 80°C and reacted for 6 hours; after the reaction, pour the system into 320mL methanol and stir vigorously at the same time to obtain a yellowish solid; In the mixed solvent of sodium hydroxide aqueous solution, stir continuously; after the reaction is completed, add acetic acid dropwise to the system to pH = 6 to obtain a white solid; filter, wash the filter cake with methanol, acetone and ether respectively; finally dissolve the filter cake in Water was treated with dialysis membrane to remove inorganic salts; it was concentrated to 120 ml, dropped into 400 ml of ethanol, and the white solid was collected by filtration and vacuum-dried to obtain 21 g of the target product. The molecular weight of xylo-oligosaccharide measured by gel filtration method is 4000-6000, and the S content of elemental analysis is 15.3%.

Example 9

Add 10g xylan to 100mL 10mg/mL barium hydroxide aqueous solution, stir at 80°C to become a suspension; add 9mL 30% hydrogen peroxide solution, and reflux for 1.5 hours; quickly cool in an ice-water bath, adjust with 1mol/L hydrochloric acid pH=5; 400mL of ethanol was added, and a white solid was precipitated. Filter and dry in vacuo to obtain 6.4 g of white solid. The yield is 64%, and the molecular weight of the xylo-oligosaccharide measured by gel filtration method is 2000-4000.

Add 60mL of α-picoline to the above 6.4g white solid; stir and heat to 60°C, slowly add 20g of pyridine sulfur trioxide to the reaction system while vigorously stirring; after adding pyridine sulfur trioxide, heat up to React at 80°C for 4 hours; after the reaction, pour the system into 320mL of methanol and stir vigorously at the same time to obtain a yellowish solid; after filtering, dissolve the filter cake in 50mL of water, and then drop into 630mL of methanol and 32mL of 33% sodium hydroxide In the mixed solvent of the aqueous solution, stir continuously; after the reaction is completed, add acetic acid dropwise to the system to pH = 6 to obtain a white solid; filter, wash the filter cake with methanol, acetone and ether respectively; finally dissolve the filter cake in water, after Dialysis membrane treatment, removal of inorganic salts; concentration to 120 ml, dropwise into 360 ml of ethanol, filtration to collect white solid, vacuum drying to obtain 10.4 g of the target product. The molecular weight of pentosan polysulfate sodium measured by gel filtration method is 4000-6000, and the S content of elemental analysis is 16.8%.

Claims (17)

1. the preparation method of an oligomeric xylose is characterized in that comprising the following step:

(1) in the aqueous solution of alkali, xylan is carried out the oxidation depolymerization reaction with hydrogen peroxide;

(2) after the reaction of step (1) finished, conditioned reaction liquid pH was 4～7, in reaction solution, adds C ₁～C ₄Fatty Alcohol(C12-C14 and C12-C18), separate out white solid, promptly make oligomeric xylose; The weight-average molecular weight of described oligomeric xylose is 2000～4000;

Wherein, the aqueous solution of alkali is the aqueous solution of earth alkali metal and/or alkali-metal oxyhydroxide, and the concentration of alkali is 1mg/ml～40mg/ml; The mass ratio of alkali and xylan is 0.01～0.4; The mass ratio of hydrogen peroxide and xylan is 0.03: 1～0.3: 1; The temperature of oxidation depolymerization reaction be 80 ℃ to reflux temperature.

2. preparation method as claimed in claim 1 is characterized in that:

In the step (1), in the aqueous solution of described alkali, the concentration of alkali is 10mg/ml～20mg/ml.

3. preparation method as claimed in claim 1 is characterized in that: in the step (1), the temperature of described oxidation depolymerization reaction be 95 ℃ to reflux temperature.

4. preparation method as claimed in claim 1 is characterized in that: in the step (1), and described C ₁～C ₄Fatty Alcohol(C12-C14 and C12-C18) be methyl alcohol or ethanol.

5. preparation method as claimed in claim 1 is characterized in that: in the step (1), the mass ratio of described hydrogen peroxide and xylan is 0.09: 1～0.18: 1; Described hydrogen peroxide is participated in reaction with the form of the aqueous solution, and the mass concentration of described aqueous hydrogen peroxide solution is 20%～40%.

6. preparation method as claimed in claim 1 is characterized in that: in the step (1), in the aqueous solution of described alkali, described earth alkali metal and/or alkali-metal oxyhydroxide are sodium hydroxide and/or Pottasium Hydroxide.

7. preparation method as claimed in claim 1 is characterized in that: in the step (1), the mass ratio of described alkali and xylan is 0.1～0.25.

8. preparation method as claimed in claim 1 is characterized in that: in the step (1), the weight-average molecular weight of described xylan is 10000～40000.

9. preparation method as claimed in claim 1 is characterized in that: the described oxidation depolymerization reaction time is 20 minutes～2 hours.

10. preparation method as claimed in claim 1 is characterized in that: in the step (1), earlier xylan is added in the aqueous solution of alkali; Become partly soluble suspension liquid; Add the aqueous hydrogen peroxide solution of mass concentration 20%～40%, to reflux temperature, react, get final product at 80 ℃.

11. preparation method as claimed in claim 1 is characterized in that: in the step (2), adding C ₁～C ₄Fatty Alcohol(C12-C14 and C12-C18) before, cooling earlier, the pH of re-adjustment reaction solution is 4～6.

12. preparation method as claimed in claim 1 is characterized in that: in the step (2), described C ₁～C ₄The adding volume of Fatty Alcohol(C12-C14 and C12-C18) be 3～8 times of reaction solution volume.

13. the oligomeric xylose that makes like each described preparation method of claim 1～12.

14. a piperylene gathers the Preparation of sodium method, it is characterized in that comprising the following step: the described oligomeric xylose of claim 13 is carried out to the reaction of sulphonate, and salt-forming reaction, get final product.

15. preparation method as claimed in claim 14; It is characterized in that: the reaction of described one-tenth sulphonate comprises the following step: under the effect of alkali; The described oligomeric xylose of claim 13 and chlorsulfonic acid and/or sulphur trioxide pyridine are carried out to the reaction of sulphonate, get final product.

16. preparation method as claimed in claim 15 is characterized in that: described alkali is one or more in pyridine, α-Jia Jibiding, beta-picoline and the γ-picoline; The consumption of alkali is 2～10 times of quality of oligomeric xylose; The consumption of described chlorsulfonic acid and/or sulphur trioxide pyridine is 3～6 times of quality of oligomeric xylose; The temperature of the reaction of described one-tenth sulphonate is 60～80 ℃; The time of the reaction of described one-tenth sulphonate is 2～24 hours.

17. preparation method as claimed in claim 14; It is characterized in that: described salt-forming reaction comprises the following step: will become product that sulphonate reaction makes to be carried out to reactant salt with the water-mixed alkoxide solution of alkali; Again after dialysis method is removed inorganic salt; Concentrate, splash in the alcohol crystallization and separate out, promptly obtain weight-average molecular weight and be 4000～6000 product.