Preparation method and application of eucommia polysaccharide

Abstract

The invention discloses a preparation method and application of eucommia polysaccharide, and belongs to the technical field of medicines. According to the method disclosed by the invention, carbon dioxide supercritical extraction is adopted, and the extraction rate, the recovery rate and the purity of the eucommia polysaccharide can be remarkably improved by optimizing the process and adopting the extraction temperature of 50-60 DEG C and the extraction pressure of 5-10MPa. The preparation method of the eucommia polysaccharide has the advantages of being green, simple and safe, and also has the advantages of being high in efficiency, reserving the physiological activity of the eucommia polysaccharide to a large extent and the like. And meanwhile, a relatively good anti-fatigue effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of medicines, and in particular relates to a preparation method of eucommia polysaccharide and application thereof. Background Art

[0002] Eucommia ulmoides Oliv. is a precious tonic herb in my country, and its resources are very abundant. Many Chinese people have the habit of using Eucommia bark as medicine, but because Eucommia trees grow slowly and extracting the bark may cause the tree to die, Eucommia bark has always been in short supply in the market.

[0003] Polysaccharides, a natural high molecular weight polymer, have anti-tumor, hypoglycemic and anti-aging functions. At present, the main method for extracting plant polysaccharides is solvent extraction, which uses strong polar solvents such as water and alcohol for extraction. However, the glycosidic bonds in polysaccharides are easily broken under excessive acid or alkaline conditions, and the extraction rate of water extraction is relatively low. Several technologies have been developed in the field of biophysics, such as ultrasound, microwave and enzyme-assisted extraction, which can improve the extraction rate and have significant advantages in reducing the requirements for organic solvents, temperature and energy consumption during the extraction process. However, the above-mentioned technologies still have problems such as long processing time, insufficient extraction efficiency and quality, and non-selective extraction.

[0004] The purpose of the present invention is to provide a method for efficiently preparing eucommia polysaccharide and its application in other aspects. Summary of the invention

[0005] In order to overcome the above technical problems, the purpose of the present invention is to provide an efficient preparation method of Eucommia polysaccharide and its application. Compared with the traditional Eucommia polysaccharide extraction and purification process, the present invention adopts carbon dioxide supercritical extraction, and through process optimization, adopts an extraction temperature of 50°C-60°C and an extraction pressure of 5-10MPa, which can significantly improve the extraction rate, recovery rate and purity of Eucommia polysaccharide. The preparation method of Eucommia polysaccharide of the present invention has the advantages of being green, simple and safe, and also has the advantages of high efficiency and retaining the physiological activity of Eucommia polysaccharide to a large extent. The present invention finds that the above-mentioned Eucommia polysaccharide has a good anti-fatigue effect.

[0006] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0007] A method for preparing eucommia polysaccharide comprises the following steps:

[0008] (1) preparing crude extract of Eucommia ulmoides polysaccharide using Eucommia ulmoides bark as raw material;

[0009] (2) The crude extract of Eucommia ulmoides polysaccharide is decolorized by using activated carbon and purified by using macroporous resin to obtain Eucommia ulmoides polysaccharide.

[0010] As a preferred embodiment, in the step (1), the Eucommia bark needs to be sieved after being crushed, and the sieve opening is 60-100 mesh, and the sieve residue is taken.

[0011] As a preferred embodiment, the crude extract of Eucommia polysaccharide prepared in step (1) is extracted by supercritical extraction with carbon dioxide.

[0012] As a preferred embodiment, the temperature of the carbon dioxide supercritical extraction in step (1) is 50°C-60°C, and the extraction pressure is 5-10 MPa.

[0013] As a preferred embodiment, the flow rate of carbon dioxide in the supercritical extraction in step (1) is 15-20 L / h.

[0014] The applicant has found that compared with traditional water extraction or alcohol extraction, the steam distillation method has the problems of long extraction time, high temperature and inactivation of effective ingredients.

[0015] The present application adopts carbon dioxide supercritical extraction, which can separate the effective components of Eucommia bark at a relatively low temperature, avoiding the destruction of the effective components by high temperature and avoiding wastewater pollution caused by the extraction solvent.

[0016] The applicant further discovered that after extraction with carbon dioxide, the mixture flows into a separator for pressurized separation, which can further improve the separation efficiency, increase the dissolution of effective ingredients, and eliminate solvent residues, thereby reducing the pressure of the next separation step.

[0017] As a preferred embodiment, the solvent in the carbon dioxide supercritical extraction in step (1) is a fatty alcohol, and preferably, the fatty alcohol is a fatty alcohol solvent having 8-30 carbon atoms.

[0018] As a preferred embodiment, the fatty alcohol is octyl dodecanol.

[0019] As a preferred embodiment, the activated carbon decolorization in step (2) comprises: dissolving the crude extract of eucommia polysaccharide prepared in 1) in a phosphate buffer solution, adding activated carbon, decolorizing at a temperature of 50°C-55°C, decolorizing for 1-2 hours, filtering, and collecting the filtrate to obtain the decolorized crude extract of eucommia plant polysaccharide.

[0020] Further, as a preferred embodiment, the activated carbon decolorization in step (2) comprises: dissolving the crude extract of Eucommia polysaccharide prepared in 1) in a phosphate buffer solution (pH 5.0) to make the polysaccharide mass concentration be 1 g / L. Adding activated carbon equivalent to 0.4% of the mass of the crude polysaccharide, decolorizing at 50°C, decolorizing for 1 hour, filtering by suction, and collecting the filtrate, which is the decolorized crude extract of Eucommia polysaccharide.

[0021] As a preferred embodiment, the purification in step (2) comprises: loading the decolorized crude extract of Eucommia ulmoides polysaccharide onto a macroporous resin (D-101) at a rate of 1.0 mL / min, eluting with a 60-65% ethanol solution at a flow rate of 0.8-1.0 mL / min, collecting the filtrate, and freeze-drying to obtain purified Eucommia ulmoides polysaccharide.

[0022] The second aspect of the present application provides the application of Eucommia ulmoides polysaccharide for use in the preparation of anti-fatigue products.

[0023] Compared with the prior art, this application has the following beneficial effects:

[0024] (1) The preparation method of Eucommia ulmoides polysaccharide described in the present application can increase the extraction amount of Eucommia ulmoides polysaccharide from Eucommia ulmoides by using supercritical carbon dioxide extraction, an extraction temperature of 50°C-60°C, and an extraction pressure of 5-10MPa, thereby obtaining safe, non-irritating, efficient and potent Eucommia ulmoides polysaccharide.

[0025] (2) The preparation method of Eucommia polysaccharide described in the present application, after extraction with supercritical carbon dioxide, flows into a separator for pressurized separation at 5-10 MPa, which can further improve the separation efficiency and increase the dissolution of effective ingredients, thereby achieving the dual effects of extraction and separation. It has the advantages of simple process flow, high extraction efficiency, no organic solvent residue, and no environmental pollution.

[0026] (3) The eucommia polysaccharide prepared by the preparation method of eucommia polysaccharide described in the present application has obvious anti-fatigue effect. DETAILED DESCRIPTION

[0027] For ease of understanding, the application will be described more fully below, and preferred embodiments of the application are provided. However, the application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. In the embodiment, if specific techniques or conditions are not indicated, the techniques or conditions described in the document in this area or according to the product specification are carried out. Reagents used or instruments that do not indicate manufacturers are conventional products that can be obtained through the market.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0029] In the present invention, the number of ingredients refers to the number of weight parts.

[0030] Example 1

[0031] (1) Crush the bark of Eucommia ulmoides and pass it through an 80-mesh sieve, take the sieve-down material, inject supercritical carbon dioxide fluid into an extraction kettle, extract for 70 minutes at a temperature of 55° C. and a pressure of 10 MPa, and obtain an extract; the extract flows into a separator along with carbon dioxide at a carbon dioxide flow rate of 20 L / h, and is separated at a certain pressure and temperature to obtain a collection liquid, dissolve the collection liquid in an octyl dodecanol solvent, stir evenly, and filter to obtain a crude extract of Eucommia ulmoides polysaccharide.

[0032] (2) decolorizing the crude extract of Eucommia polysaccharide with activated carbon, wherein the activated carbon decolorization comprises: dissolving the crude extract of Eucommia polysaccharide prepared in 1) in a phosphate buffer solution (pH 5.0) to make the polysaccharide mass concentration be 1 g / L, adding activated carbon equivalent to 0.4% of the mass of the crude polysaccharide, decolorizing at 50° C. for 1 hour, filtering by suction, and collecting the filtrate, which is the decolorized crude extract of Eucommia polysaccharide.

[0033] The decolorized crude extract of Eucommia ulmoides polysaccharide was loaded into the macroporous resin (D-101) at a rate of 1.0 mL / min, and eluted with 65% ethanol solution at a flow rate of 1.0 mL / min. The filtrate was collected and freeze-dried to obtain purified Eucommia ulmoides polysaccharide.

[0034] Example 2

[0035] (1) Crush the bark of Eucommia ulmoides and pass it through a 100-mesh sieve, take the sieve-down material, inject supercritical carbon dioxide fluid into an extraction kettle, extract for 70 minutes at a temperature of 60° C. and a pressure of 10 MPa, and obtain an extract; the extract flows into a separator along with carbon dioxide at a carbon dioxide flow rate of 15 L / h, and is separated at a certain pressure and temperature to obtain a collection liquid, dissolve the collection liquid in an octyl dodecanol solvent, stir evenly, and filter to obtain a crude extract of Eucommia ulmoides polysaccharide.

[0036] (2) decolorizing the crude extract of Eucommia polysaccharide with activated carbon, wherein the activated carbon decolorization comprises: dissolving the crude extract of Eucommia polysaccharide prepared in 1) in a phosphate buffer solution (pH 5.0) to make the polysaccharide mass concentration be 1 g / L, adding activated carbon equivalent to 0.4% of the mass of the crude polysaccharide, decolorizing at 50° C. for 1 hour, filtering by suction, and collecting the filtrate, which is the decolorized crude extract of Eucommia polysaccharide.

[0037] The decolorized crude extract of Eucommia ulmoides polysaccharide was loaded into the macroporous resin (D-101) at a rate of 1.0 mL / min, and eluted with 60% ethanol solution at a flow rate of 0.8 mL / min. The filtrate was collected and freeze-dried to obtain purified Eucommia ulmoides polysaccharide.

[0038] Example 3

[0039] (1) Crush the bark of Eucommia ulmoides through a 60-mesh sieve, take the sieve material, inject supercritical carbon dioxide fluid into an extraction kettle, extract for 70 minutes at a temperature of 55° C. and a pressure of 5 MPa to obtain an extract; let the extract flow into a separator with carbon dioxide at a flow rate of 15 L / h, separate at a certain pressure and temperature to obtain a collection liquid, dissolve the collection liquid in an octyl dodecanol solvent, stir evenly, and filter to obtain a crude extract of Eucommia ulmoides polysaccharide.

[0040] (2) decolorizing the crude extract of Eucommia polysaccharide with activated carbon, wherein the activated carbon decolorization comprises: dissolving the crude extract of Eucommia polysaccharide prepared in 1) in a phosphate buffer solution (pH 5.0) to make the polysaccharide mass concentration be 1 g / L, adding activated carbon equivalent to 0.4% of the mass of the crude polysaccharide, decolorizing at 50° C. for 1 hour, filtering by suction, and collecting the filtrate, which is the decolorized crude extract of Eucommia polysaccharide.

[0041] The decolorized crude extract of Eucommia ulmoides polysaccharide was loaded into the macroporous resin (D-101) at a rate of 1.0 mL / min, and eluted with 60% ethanol solution at a flow rate of 1.0 mL / min. The filtrate was collected and freeze-dried to obtain purified Eucommia ulmoides polysaccharide.

[0042] Example 4

[0043] (1) Crush the bark of Eucommia ulmoides and pass it through an 80-mesh sieve, take the sieve-down material, inject supercritical carbon dioxide fluid into an extraction kettle, extract for 70 minutes at a temperature of 60° C. and a pressure of 5 MPa, and obtain an extract; the extract flows into a separator along with carbon dioxide at a carbon dioxide flow rate of 20 L / h, and is separated at a certain pressure and temperature to obtain a collection liquid, dissolve the collection liquid in an octyl dodecanol solvent, stir evenly, and filter to obtain a crude extract of Eucommia ulmoides polysaccharide.

[0044] (2) decolorizing the crude extract of Eucommia polysaccharide with activated carbon, wherein the activated carbon decolorization comprises: dissolving the crude extract of Eucommia polysaccharide prepared in 1) in a phosphate buffer solution (pH 5.0) to make the polysaccharide mass concentration be 1 g / L, adding activated carbon equivalent to 0.4% of the mass of the crude polysaccharide, decolorizing at 50° C. for 1 hour, filtering by suction, and collecting the filtrate, which is the decolorized crude extract of Eucommia polysaccharide.

[0045] The decolorized crude extract of Eucommia ulmoides polysaccharide was loaded into the macroporous resin (D-101) at a rate of 1.0 mL / min, and eluted with 65% ethanol solution at a flow rate of 0.8 mL / min. The filtrate was collected and freeze-dried to obtain purified Eucommia ulmoides polysaccharide.

[0046] Comparative Example 1

[0047] Compared with Example 1, the difference is that a water extraction method is used to obtain the crude polysaccharide extract of Eucommia ulmoides.

[0048] (1) Take dried Eucommia bark, grind it with a grinder, wash it with distilled water to remove impurities, add distilled water to the Eucommia powder at a solid-liquid ratio of 1:15 (g / mL) and soak it for 24 hours, decoct it after soaking, and continue to decoct it for 2 hours on a low heat after the liquid is boiled, filter the supernatant after cooling, and repeat the decoction extraction for 2 times on the residue, combine the filtrate after three decoctions, and concentrate it by rotary evaporation to obtain a concentrated solution; add 4 times the volume of anhydrous ethanol to the concentrated solution, let it stand for 24 hours, collect the precipitate by centrifugation, air-dry it and freeze-dry it, and redissolve the crude polysaccharide in distilled water to obtain a crude Eucommia polysaccharide extract;

[0049] The following steps are the same as in Example 1.

[0050] Comparative Example 2

[0051] Compared with Example 1, the difference is that no alcohol solution is used.

[0052] (1) Crush the bark of Eucommia ulmoides and pass it through an 80-mesh sieve, take the sieve-down material, inject supercritical carbon dioxide fluid into an extraction kettle, extract for 70 minutes at a temperature of 55° C. and a pressure of 10 MPa, and obtain an extract; the extract flows into a separator along with carbon dioxide at a carbon dioxide flow rate of 20 L / h, and is separated at a certain pressure and temperature to obtain a collection liquid, and the collection liquid is filtered to obtain a crude extract of Eucommia ulmoides polysaccharide.

[0053] (2) decolorizing the crude extract of Eucommia polysaccharide with activated carbon, wherein the activated carbon decolorization comprises: dissolving the crude extract of Eucommia polysaccharide prepared in 1) in a phosphate buffer solution (pH 5.0) to make the polysaccharide mass concentration be 1 g / L, adding activated carbon equivalent to 0.4% of the mass of the crude polysaccharide, decolorizing at 50° C. for 1 hour, filtering by suction, and collecting the filtrate, which is the decolorized crude extract of Eucommia polysaccharide.

[0054] The decolorized crude extract of Eucommia ulmoides polysaccharide was loaded into the macroporous resin (D-101) at a rate of 1.0 mL / min, and eluted with 65% ethanol solution at a flow rate of 1.0 mL / min. The filtrate was collected and freeze-dried to obtain purified Eucommia ulmoides polysaccharide.

[0055] Comparative Example 3

[0056] Compared with Example 1, the difference is that the carbon dioxide supercritical extraction parameters are different.

[0057] (1) Crush the bark of Eucommia ulmoides through an 80-mesh sieve, take the sieve-down material, inject supercritical carbon dioxide fluid into an extraction kettle, extract for 70 minutes at a temperature of 40° C. and a pressure of 20 MPa, and obtain an extract; the extract flows into a separator along with carbon dioxide at a carbon dioxide flow rate of 30 L / h, and is separated at a certain pressure and temperature to obtain a collection liquid, dissolve the collection liquid in an octyl dodecanol solvent, stir evenly, and filter to obtain a crude extract of Eucommia ulmoides polysaccharide.

[0058] (2) decolorizing the crude extract of Eucommia polysaccharide with activated carbon, wherein the activated carbon decolorization comprises: dissolving the crude extract of Eucommia polysaccharide prepared in 1) in a phosphate buffer solution (pH 5.0) to make the polysaccharide mass concentration be 1 g / L, adding activated carbon equivalent to 0.4% of the mass of the crude polysaccharide, decolorizing at 50° C. for 1 hour, filtering by suction, and collecting the filtrate, which is the decolorized crude extract of Eucommia polysaccharide.

[0059] The decolorized crude extract of Eucommia ulmoides polysaccharide was loaded into the macroporous resin (D-101) at a rate of 1.0 mL / min, and eluted with 65% ethanol solution at a flow rate of 1.0 mL / min. The filtrate was collected and freeze-dried to obtain purified Eucommia ulmoides polysaccharide.

[0060] Example 5

[0061] 1. Determination of Eucommia polysaccharide and protein content

[0062] 1. Determination of Eucommia Polysaccharide Content

[0063] The phenol-sulfuric acid method was used to determine the content of Eucommia polysaccharides. In this experiment, 100 μg / mL glucose was used as the standard solution. 0 mL, 1 mL, 2 mL, 3 mL, 4 mL, 5 mL of glucose solution and 10 mL (11 mg / mL) of Eucommia polysaccharides were transferred into 10 mL and 50 mL volumetric flasks, respectively. 5 mL of 5% phenol solution and 10 mL of concentrated sulfuric acid were added, respectively. After fully mixing, the mixture was shaken. The above solution was placed in boiling water for color development for 15 min. After the solution was cooled, UV-visible absorption spectroscopy was performed to obtain a linear curve of mass-absorbance. The polysaccharide content was measured based on the linear curve and absorbance.

[0064] The extraction rate formula of polysaccharides is:

[0065] N=M1 / M2×100%

[0066] Wherein, N is the extraction rate of Eucommia ulmoides polysaccharide (%); M1 is the mass of polysaccharide in the crude extract (g); M2 is the mass of Eucommia ulmoides (g).

[0067] The recovery formula of polysaccharide after purification is:

[0068] Z=B1 / B2×100%

[0069] Wherein, Z is the recovery rate of Eucommia polysaccharide after purification (%); B1 is the content of polysaccharide after purification (g); B2 is the content of polysaccharide in the crude extract (g).

[0070] 2. Determination of protein content in Eucommia polysaccharides

[0071] The BCA (Bicinchoninic Acid Assay) method was used to detect the protein content in the Eucommia polysaccharide sample. The protein clearance formula in the polysaccharide is:

[0072] W=(1-Y1 / Y2)×100%

[0073] Wherein, W is the protein clearance rate after purification (%); Y1 is the protein content after purification (g); Y2 is the protein content in the crude extract (g).

[0074] A total of 7 groups were set up, including Example 1-4, Comparative Example 1-3, and 3 replicates in each group. The extraction rate, recovery rate, and protein clearance rate of each group are shown in Table 1:

[0075] Table 1 Results of extraction rate, recovery rate and protein clearance rate of Eucommia polysaccharide

[0076]

[0077]

[0078] The above results show that the extraction rate and recovery rate of Eucommia polysaccharide in Examples 1-4 of the present invention are much higher than those in Comparative Examples 1-3.

[0079] 2. Evaluation of anti-fatigue effect

[0080] After the mice were adaptively fed for 1 week, they were randomly divided into 13 groups according to body weight: blank control group, samples of Examples 1-4 of the present invention, Comparative Examples 1-4, commercially available sea cucumber peptide products, Rhodiola rosea, ginseng, and Red Bull beverage, with 10 mice in each group. The groups of Example 3 of the present invention, Comparative Examples 1-8, commercially available sea cucumber peptide products, Rhodiola rosea, ginseng, etc. were all gavaged at a dose of 2g / kg / d (in terms of crude drug amount), Red Bull beverage was gavaged at 2ml / d, and the blank control group was given an equal volume of normal saline, and each group was gavaged once a day for 15 consecutive days.

[0081] Mouse weighted swimming test: 30 minutes after the last administration, the mouse tail was loaded with a weight, the weight of which was 10% of the mouse's own weight, and placed in a mouse constant temperature swimming pool, the water temperature was (25.0±0.5)℃, and the timer was started after the mouse was placed in. The time when the mouse sank under the water surface and could not float to the surface after 10s was recorded as the exhaustive swimming time. After swimming, blood was collected from the mouse's eye sockets and serum was separated. The mouse was killed by dislocation of the neck and the mouse's hind leg muscles were taken. The serum samples were tested for blood lactate, serum urea nitrogen and muscle glycogen levels.

[0082] The experimental data were statistically analyzed using SPSS 22.0 statistical software, and the statistical value was expressed as mean ± standard deviation (x ± s). One-way analysis of variance was used for comparison between groups. The statistical results are shown in Table 2.

[0083] Table 2 Anti-fatigue effect data

[0084]

[0085]

[0086] Compared with the blank group, * P<0.05, ** P<0.01. Compared with the commercially available sea cucumber peptide group, △ P<0.05, △△ P<0.01. Compared with the Rhodiola rosea group, # P<0.05, ## P<0.01. Compared with the ginseng group, & P<0.05, && P<0.01. Compared with the Red Bull group, § P<0.05, §§ P<0.01.

[0087] The results of the anti-fatigue effect experiment are shown in Table 2. The sample groups of Examples 1-4 of the present invention, the commercially available sea cucumber peptide group, the rhodiola rosea group, the ginseng group, and the Red Bull beverage group can all prolong the weight-bearing swimming time of mice, and there are significant differences compared with the blank group (P<0.05 or 0.01); the blood lactate and serum urea nitrogen levels of the above groups are all decreased, and there are significant differences compared with the blank group (P<0.05 or 0.01); and the muscle glycogen levels of the above groups are all increased, and there are significant differences compared with the blank group (P<0.05 or 0.01); indicating that the above samples have obvious anti-fatigue effects.

[0088] The results in Table 2 also show that the weighted swimming time, blood lactate, serum urea nitrogen, muscle glycogen and other indicators of the sample groups of Comparative Examples 1-3 are lower than those of the sample groups of Examples 1-4, and there is no significant change compared with the blank group, indicating that the anti-fatigue effect of the samples of Comparative Examples 1-3 is not great. In addition, the weighted swimming time, blood lactate, serum urea nitrogen, muscle glycogen and other indicators of the sample groups of Examples 1-4 of the present invention are compared with the control groups such as the commercial sea cucumber peptide group, rhodiola rosea group, ginseng group, and Red Bull beverage group, and there are significant differences (P<0.05 or 0.01), indicating that the composition sample containing eucommia alcohol and quercetin prepared by the method of the present invention has a significant anti-fatigue effect, and its effect is also better than commercially available anti-fatigue products.

[0089] The above anti-fatigue experimental results show that the composition containing eucommia alcohol and quercetin prepared by the method of the present invention has a clear anti-fatigue effect.

[0090] The above-mentioned embodiments only express the implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for preparing Eucommia ulmoides polysaccharide, characterized in that: The following steps are involved: (1) preparing crude extract of Eucommia ulmoides polysaccharide using Eucommia ulmoides bark as raw material; (2) The crude extract of Eucommia ulmoides polysaccharide is decolorized by using activated carbon and purified by using macroporous resin to obtain Eucommia ulmoides polysaccharide.

2. The method for preparing eucommia polysaccharide according to claim 1, characterized in that: In the step (1), the Eucommia bark needs to be sieved after being crushed, and the sieve opening is 60-100 meshes, and the sieve residue is taken.

3. The method for preparing eucommia polysaccharide according to claim 1, characterized in that: In the step (1), the crude extract of Eucommia ulmoides polysaccharide is prepared by supercritical extraction with carbon dioxide.

4. The method for preparing eucommia polysaccharide according to claim 3, characterized in that: The flow rate of carbon dioxide in the supercritical extraction of step (1) is 15-20 L / h.

5. The method for preparing eucommia polysaccharide according to claim 3, characterized in that: The solvent in the carbon dioxide supercritical extraction in step (1) is a fatty alcohol, and the carbon number of the fatty alcohol is a fatty alcohol solvent of 8-30.

6. The method for preparing eucommia polysaccharide according to claim 5, characterized in that: The fatty alcohol is octyl dodecanol.

7. The method for preparing eucommia polysaccharide according to claim 1, characterized in that: The activated carbon decolorization in step (2) comprises: dissolving the crude extract of eucommia polysaccharide prepared in (1) in a phosphate buffer solution, adding activated carbon, decolorizing at a temperature of 50°C-55°C, decolorizing for 1-2 hours, filtering, and collecting the filtrate to obtain the decolorized crude extract of eucommia polysaccharide.

8. The method for preparing eucommia polysaccharide according to claim 1, characterized in that: The activated carbon decolorization in step (2) comprises: dissolving the crude extract of eucommia polysaccharide prepared in (1) in a phosphate buffer solution (pH 5.0) to make the polysaccharide mass concentration be 1 g / L, adding activated carbon equivalent to 0.4% of the mass of the crude polysaccharide, decolorizing at a temperature of 50° C. for a decolorizing time of 1 hour, filtering by suction, and collecting the filtrate to obtain the decolorized crude extract of eucommia plant polysaccharide.

9. The method for preparing eucommia polysaccharide according to claim 1, characterized in that: The purification in step (2) comprises: loading the decolorized eucommia plant polysaccharide crude extract onto a macroporous resin (D-101) at a rate of 1.0 mL / min, eluting with a 60-65% ethanol solution at a flow rate of 0.8-1.0 mL / min, collecting the filtrate, and freeze-drying to obtain purified eucommia polysaccharide.

10. Use of the eucommia polysaccharide according to any one of claims 1 to 9 in the preparation of anti-fatigue products.

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