WO2022077853A1 - Method for extracting grifola frondosa active polysaccharide, and extracted active polysaccharide and use thereof - Google Patents

Abstract

The present invention relates to a method for extracting grifola frondosa active polysaccharide on the basis of a membrane filtration technology, and grifola frondosa active polysaccharide extracted by the method and a use thereof. The method comprises: (1) adding water to a grifola frondosa sporocarp raw material, and performing combination and vacuum concentration to obtain a grifola frondosa extract concentrate; (2) performing microfiltration pretreatment on the grifola frondosa extract concentrate; (3) performing ultrafiltration treatment on the microfiltration permeate; and (4) drying the ultrafiltration retentate to obtain grifola frondosa polysaccharide. The present invention has beneficial effects that: (1) active components in the grifola frondosa extract are prevented from being damaged to the maximum extent, and a separation process is equivalent to primary pre-concentration; the ultrafiltration technology in the present invention is very suitable for separating effective components in the extract and removing components which are poor and even invalid in efficacy; the purity of the prepared grifola frondosa polysaccharide is higher than that of polysaccharide prepared by means of a conventional process; the ultrafiltration effect is improved, the membrane pollution is reduced, the production efficiency is improved, the service life of the ultrafiltration membrane is prolonged, and the costs are reduced; and the present invention is suitable for industrialization and has good economic prospects.

Description

A kind of extraction method of Grifola frondosa active polysaccharide and extracted active polysaccharide and use technical field

The invention relates to a method for extracting polysaccharide, in particular to a method for extracting active polysaccharide from Grifola frondosa based on membrane filtration technology, and the active polysaccharide from Grifola frondosa extracted by the method and its application.

Background technique

Grifola frondosa is a traditional edible and medicinal fungus in my country, which has good health care function and high medicinal value. Research results at home and abroad show that Grifola has the effects of reducing insulin resistance, controlling blood sugar, inhibiting the accumulation of fat cells, lowering blood pressure, enhancing immunity and anti-cancer.

Grifola frondosa polysaccharide is an extract from Grifola frondosa. It is composed of glucan, small molecule monosaccharide and a small amount of protein heterosaccharide complexes. Animal experiments and clinical experiments have shown that it can activate phagocytes, induce Apoptosis of cancer cells to play anti-cancer and anti-cancer effects.

At present, the extraction and preparation of Grifola frondosa polysaccharides generally adopts water extraction and alcohol precipitation. After hot water extraction, ethanol is added to remove water-soluble small molecular impurities such as water-soluble proteins and monosaccharides, and crude polysaccharides are precipitated. However, because the purification efficiency of alcohol precipitation is low, the composition in the precipitate is complex, the polysaccharide content is reduced, the efficacy and activity is affected, and the amount of ethanol used is large, resulting in high polysaccharide preparation and production cost, and causing a certain degree of environmental pollution.

SUMMARY OF THE INVENTION

In view of the above deficiencies, the present invention provides a method for extracting Grifola frondosa active polysaccharide based on membrane filtration technology, which can greatly simplify the preparation process of Grifola frondosa polysaccharide, the extracted polysaccharide has high purity, and the extraction is performed in reverse according to the effect of the active polysaccharide. Screening of method parameters, such as ultrafiltration parameters, can make the extracted active polysaccharide have a significant effect, and also realize the industrial application of the extraction method.

The present invention achieves the above object through the following schemes:

A first aspect, a method for extracting active polysaccharide from Grifola frondosa, comprising:

(1) Add water 10-40 times the weight of the raw material to the Grifola frondosa fruiting body raw material, extract 1-4 times at 80-105 ° C, extract 1-4 hours each time, filter the extract at 80-200 mesh; merge the extract , vacuum concentrated to solid content 5-20% to obtain Grifola frondosa extract concentrate;

(2) Microfiltration pretreatment is carried out on the extract of Grifola frondosa, the pore size of the microfiltration membrane is 100-400nm, the temperature is controlled at 25-60°C, and the operating pressure is within 1MPa, the microfiltration permeate is collected, and the microfiltration unpermeable liquid is discarded. liquid;

(3) The microfiltration permeate is subjected to ultrafiltration treatment. The pore size of the ultrafiltration membrane corresponds to the intercepted molecular weight of 1-18KDa, the operating pressure is 0.3-1MPa, and the temperature is controlled at 25-40°C. When the volume of the permeate is 40% of the total volume Stop the ultrafiltration when -75%, keep the ultrafiltration retentate that does not permeate the membrane, and discard the ultrafiltration permeate;

(4) drying the ultrafiltration retentate, and controlling the moisture content of the powder to be less than 15%, the obtained dry powder is the Grifola frondosa polysaccharide.

Preferably, the invention further optimizes the parameters of the above extraction method to obtain a method with higher extraction efficiency and better purity: a method for extracting active polysaccharide from Grifola frondosa, comprising:

(1) Add water 10-25 times the weight of the raw material to the Grifola frondosa fruiting body raw material, extract 2-3 times at 95-105°C, extract 1-2 hours each time, filter the extract with 100-200 mesh; merge the extract , vacuum concentrated to solid content 10-18% to obtain Grifola frondosa extract concentrate;

(2) Microfiltration pretreatment is carried out on the extract of Grifola frondosa, the pore size of the microfiltration membrane is 100-200 nm, the temperature is controlled at 25-55 °C, and the operating pressure is within 0.8 MPa, the microfiltration permeate is collected, and the microfiltration unfiltered liquid is discarded. permeate;

(3) The microfiltration permeate is subjected to ultrafiltration treatment, the pore size of the ultrafiltration membrane corresponds to the intercepted molecular weight of 2-15KDa, the operating pressure is 0.3-0.6MPa, and the temperature is controlled at 25-35°C. When the volume of the permeate is 55% of the total volume %-75%, stop the ultrafiltration, keep the ultrafiltration retentate that does not pass through the membrane, and discard the ultrafiltration permeate;

(4) drying the ultrafiltration retentate, and controlling the moisture content of the powder to be less than 12%, the obtained dry powder is the Grifola frondosa polysaccharide.

The inventor found that in the Grifola frondosa extract, the relative molecular weights of the components such as Grifola frondosa water-soluble amino acids and monosaccharides are generally lower than 1KDa, while the relative molecular weights such as starch and cellulose are very large, so the use of ultrafiltration technology is very important. It is suitable for separating the effective components in the extract and removing the components with poor efficacy or even ineffectiveness.

In the preparation method provided by the present invention, the separation process is equivalent to one-time pre-concentration, and then the microfiltration and ultrafiltration technologies are used in combination, which has the advantages of simple operation, low energy consumption, short production cycle, the filter membrane can be used multiple times, and the whole process of filtration is low temperature. There is no solvent residue in the operation, which can prevent the destruction of the active components in the Grifola frondosa extract to the greatest extent.

Further, the inventor continuously adjusted the laboratory-scale extraction method to obtain an industrialized extraction method for Grifola frondosa active polysaccharide, including:

(1) Put the Grifola frondosa fruit body raw material into the extraction tank, add water 10-40 times the weight of the raw material, extract 1-4 times at 80-105 ° C, extract 1-4 hours each time, pass the extract through the filter, The aperture of the filter screen is 80-200 meshes; the extracts are combined and concentrated in vacuo to a solid content of 5-20% to obtain the Grifola frondosa extraction concentrate;

(2) Introduce the extract concentrate of Grifola frondosa into the microfiltration equipment for pretreatment, the pore size of the microfiltration membrane is 100-400nm, the temperature is controlled at 25-60°C, and the operating pressure is within 1MPa, the microfiltration permeate is collected, and the microfiltration is discarded. no permeate;

(3) The microfiltration permeate is introduced into the ultrafiltration equipment, and the polysaccharides of different molecular weights are intercepted and purified with an ultrafiltration membrane. The pore size of the ultrafiltration membrane corresponds to the intercepted molecular weight of 1-18KDa, the operating pressure is 0.3-1MPa, and the temperature is controlled at 25-40 ℃, when the volume of the permeate is controlled at 40%-75% of the total volume, the ultrafiltration is stopped, the ultrafiltration retentate that does not permeate the membrane is retained, and the ultrafiltration permeate is discarded;

(4) drying the ultrafiltration retentate, and controlling the moisture content of the finished powder to be less than 15%, the obtained dry powder is the finished product of Grifola frondosa polysaccharide.

Further, the inventor has successfully optimized the extraction method of the industrialized Grifola frondosa active polysaccharide in the laboratory-scale extraction method in combination with the above-mentioned research on extraction efficiency and purity, including:

(1) put the Grifola frondosa fruit body raw material into the extraction tank, add 10-25 times of water of the raw material weight, extract 2-3 times at 95-105 ° C, extract 1-2 hours each time, and pass the extract through the filter screen, The aperture of the filter screen is 100-200 meshes; the extracts are combined and concentrated to a solid content of 10-18% in a vacuum to obtain a Grifola frondosa extraction concentrate;

(2) Introduce the concentrated liquid of Grifola frondosa extraction into the microfiltration equipment for pretreatment, the microfiltration membrane pore size is 100-200nm, the temperature is controlled at 25-55°C, and the operating pressure is within 0.8MPa, the microfiltration permeate is collected, and the microfiltration permeate is discarded. Filter the permeate;

(3) The microfiltration permeate is introduced into the ultrafiltration equipment, and the polysaccharides of different molecular weights are intercepted and purified by the ultrafiltration membrane. The pore size of the ultrafiltration membrane corresponds to the intercepted molecular weight of 2-15KDa, the operating pressure is 0.3-0.6MPa, and the temperature is controlled at 25-35 ℃, when the volume of the permeate is controlled at 55%-75% of the total volume, the ultrafiltration is stopped, the ultrafiltration retentate that does not permeate the membrane is retained, and the ultrafiltration permeate is discarded;

(4) drying the ultrafiltration retentate, and controlling the moisture content of the finished powder to be less than 12%, the obtained dry powder is the finished product of Grifola frondosa polysaccharide.

Preferably, the drying of the ultrafiltration retentate includes: one or more of spray drying, freeze drying, vacuum drying or normal pressure drying.

Preferably, the microfiltration membrane material is one or more of ceramic membranes, organic polymer membranes, and metal membranes.

Preferably, the pore size of the ultrafiltration membrane is less than 100 nm, the molecular weight cutoff is in the range of 1-18KDa, and the ultrafiltration membrane material is one or more of ceramic membranes, organic polymer membranes, and metal membranes.

In the above-mentioned extraction method of Grifola frondosa active polysaccharide, the microfiltration operation belongs to a physical extraction liquid pretreatment method, and similar pretreatments such as vacuum filtration, activated carbon decolorization, low-speed centrifugation, and high-speed centrifugation can also be used. method; however, the inventor found that the combination of microfiltration and ultrafiltration is more conducive to the extraction of Grifola frondosa active polysaccharide and the life of the ultrafiltration membrane, and the extraction cost is saved.

The second method, the present invention provides a Grifola frondosa polysaccharide extracted by the above extraction method.

The composition analysis of the Grifola frondosa polysaccharide is shown in Figure 2 and Table 2.

Compared with the Grifola frondosa polysaccharide prepared by the traditional method, the molecular weight distribution of the Grifola frondosa active polysaccharide is more concentrated and the purity is higher.

In a third aspect, the present invention provides the use of the Grifola frondosa active polysaccharide obtained by the above extraction in hypoglycemic.

In a fourth aspect, the present invention provides the use of the Grifola frondosa active polysaccharide obtained by the above extraction in preparing a hypoglycemic drug.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The use of microfiltration and ultrafiltration technology has the advantages of simple operation, low energy consumption, short production cycle, and the filter membrane can be used multiple times. Active ingredients, while the separation process is equivalent to a pre-concentration;

(2) The relative molecular weights of components such as Grifola frondosa water-soluble amino acids and monosaccharides are generally lower than 1KDa, while relative molecular weights such as starch and cellulose are very large, so the ultrafiltration technology of the present invention is very suitable for separating the effective The purity of the prepared Grifola polysaccharide is higher than that of the polysaccharide prepared by the traditional process;

(3) In the present invention, the extraction solution is treated by microfiltration before ultrafiltration to remove larger suspended particles or colloidal substances in the extraction solution, thereby improving the ultrafiltration effect, reducing membrane pollution, helping to improve production efficiency and prolonging the service life of ultrafiltration membranes ,cut costs;

(4) The operation process does not involve ethanol, which saves the production cost and improves the convenience and safety of the production operation at the same time.

(5) The method of the present invention is suitable for industrialization and has good economic prospects.

(6) The Grifola frondosa polysaccharide extracted by the present invention has higher purity, more concentrated molecular weight distribution, and more significant hypoglycemic effect.

Description of drawings

FIG. 1 is a molecular weight distribution diagram of Grifola frondosa polysaccharide (GFE) in Test Example 1. FIG.

FIG. 2 is a molecular weight distribution diagram of the Grifola frondosa active polysaccharide (GFH5) of the present invention in Test Example 1. FIG.

Detailed ways

The present invention will be further described below in conjunction with specific embodiments.

Example 1:

(1) Put 100kg of Grifola frondosa fruit bodies with a moisture content of about 12% into the extraction tank, add 25 times of water, extract at 100 ° C for 4 hours, pass the extract through a 100-mesh filter screen, introduce a double-effect concentration device, and concentrate to a solid content of 10 % concentrated solution to obtain 470L of concentrated solution;

(2) The concentrated solution is introduced into the microfiltration equipment, the pore size of the filter membrane is 200 nm, the temperature is 55 ° C, the operating pressure is lower than 0.5 MPa, and the permeate yield is 90%;

(3) The microfiltration permeate is introduced into the ultrafiltration equipment. The pore size of the ultrafiltration membrane corresponds to the molecular weight of 5KDa or more, the operating pressure is 0.5MPa, and the temperature is controlled at 35°C. When the permeate reaches 60% of the total volume, the ultrafiltration is stopped. , retaining the ultrafiltration retentate that did not permeate the membrane to obtain 170L of the retentate;

(4) Introducing the ultrafiltration retentate into a spray drying device, controlling the inlet air temperature to 170° C., spray drying to a powder moisture content of about 10%, and the obtained dry powder is the Grifola frondosa polysaccharide finished product.

Finally, 9.57kg of finished product was obtained, and the polysaccharide content in the finished product was 4.38g/100g.

Test Example 1

Using the Grifola frondosa polysaccharide sample (named GFH5) in Example 1, and preparing common Grifola frondosa polysaccharide (named GFE) at the same time, the polysaccharide molecular weight distribution of the two samples was determined.

Wherein, the preparation method of common Grifola frondosa polysaccharide:

(1) Put 100kg of Grifola frondosa fruit bodies with a moisture content of about 12% into the extraction tank, add 25 times of water, extract at 100 ° C for 4 hours, pass the extract through a 100-mesh filter screen, introduce a double-effect concentration device, and concentrate to a solid content of 10 % concentrated solution to obtain 470L of concentrated solution;

(2) Introducing the concentrated solution into a spray drying device, controlling the inlet air temperature to 170° C., spray drying to a powder moisture content of about 10%, and the obtained dry powder is the finished product of Grifola frondosa polysaccharide.

The measurement results are shown in Table 1-Table 2 and Figure 1 and Figure 2:

Table 1: Grifola frondosa polysaccharide (GFE)

serial number	keep time	Peak area%	number average molecular weight	weight average molecular weight
1	44.967	2.66	13452	13945
2	50.025	16.69	1415	1501
3	51.800	80.65	515	536

Table 2: Grifola frondosa active polysaccharide (GFH5)

serial number	keep time	Peak area%	number average molecular weight	weight average molecular weight
1	17.417	7.21	14032	16892
2	19.217	36.00	1960	2755
3	20.052	56.79	302	397

As can be seen from the results of Figure 1 and Figure 2 and Table 1 and Table 2, compared with the common Grifola frondosa polysaccharide prepared by the traditional process, the molecular weight distribution of the Grifola frondosa active polysaccharide extracted by the present invention is more concentrated, and the purity is higher than Polysaccharides prepared by traditional techniques.

Test Example 2

Using the Grifola frondosa polysaccharide in Example 1 as a sample (named GFH5), animal experiments were performed to evaluate the hypoglycemic activity. At the same time, Grifola frondosa polysaccharide (GFE) was prepared as a control.

The preparation of Grifola frondosa polysaccharide (GFE) refers to the method of Test Example 1.

1. Method

Healthy male SD rats, weighing 160-180 g, with 111 rats, were purchased from the Guangdong Provincial Medical Laboratory Animal Center. The rats were housed in the SPF animal room of the Guangdong Provincial Laboratory Animal Monitoring Institute at a temperature of 22-23°C and a relative humidity of 50-60%.

Modeling method: Feeding animals with high-sugar and high-fat diet can form an animal model of glucose metabolism disorder, and then intraperitoneal injection of alloxan can form insulin resistance, induce experimental diabetes, and form a type 2 diabetes rat model.

Dosing method: The recommended dose of human body (1.8g/d) was set as 112.5, 225, 675 mg/kg·BW for low, medium and high dose groups, which is equivalent to 5 times, 10 times and 30 times of the recommended dose of human body. The GFE group was given 675 mg/kg·BW by intragastric administration, which was equivalent to 30 times the recommended human dose. At the same time, a normal control group and a negative control group were set up, and the same amount of vehicle was administered orally, and the positive control group was administered with metformin hydrochloride tablets 200 mg/kg by intragastric administration. The body weight was weighed every 3 days, and the amount of gavage was adjusted accordingly. The test samples were continuously gavaged for 48 days. Test method: After the adaptation period, the rats were randomly divided into groups according to their body weight, with 15 rats in each of the normal group, model group and positive group, and 16 rats in each of the three dose groups of GFE and GFH5. The test samples of different concentrations were given to the stomach, the model control group was given the same volume of solvent, and the normal group was left untreated. After 3 consecutive weeks, the model control group and the sample group were fasted for 24 hours (without water), and given alloxan 103 mg/kg.BW intraperitoneal injection, the injection volume was 1 mL/100 g body weight. Continue to give high-calorie feed for 20 days after injection. On the 20th day after injection, the rats in each group were fasted for 4 hours, and fasting blood glucose and glucose tolerance were detected.

Animal groupings are shown in Table 3:

Table 3 Experimental animal groupings and doses

Group (n=7)	Number of animals/only	Dosage/mg/kg
normal control group	15
High glucose model control group	15	solvent
Positive control group (metformin)	15	200
GFH5 - low dose	16	112.5
GFH5-medium dose	16	225
GFH5 - high dose	16	675
GFE	16	675

2. Results

The results of fasting blood glucose and glucose tolerance of rats on the 20th day of modeling are shown in Table 4.

Table 4 Effects of different samples on blood glucose and glucose tolerance in diabetic rats

Note: Compared with the normal group, *P<0.05;**P<0.01; compared with the model group, ^# P<0.05;^## P≤0.01.

As can be seen from Table 4, on the 20th day of modeling, compared with the model control group, the GFH5 low-dose and middle-dose administration groups had fasting blood glucose, blood glucose at 0.5, 2 hours after glucose administration, and 0, 0.5, and 2 hours. The reduction of the area under the blood glucose curve was statistically significant, so the results of fasting blood glucose and glucose tolerance indexes in the low-dose and middle-dose groups of GFH5 were determined to be positive. Compared with the model group, there was no significant difference in the decrease of fasting blood glucose at high dose of GFH5, but the decrease of blood glucose and the area under the curve of blood glucose at 0.5 and 2 hours after glucose administration was statistically significant.

The results showed that the GFE administration group had no hypoglycemic effect, and the hypoglycemic effect of each dose group of GFH5 was significant, especially the low dose group and the middle dose group of GFH5. It shows that the Grifola frondosa polysaccharide prepared by the method of the present invention has good hypoglycemic activity.

The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. The equivalent replacement or modification of the solution and its concept shall be included within the protection scope of the present invention.

Claims (9)

1. A method for extracting Grifola frondosa active polysaccharide, comprising:

   (1) Add water of 10-40 times the weight of the raw material to the Grifola frondosa fruiting body raw material, extract 1-4 times at 80-105 ° C, extract 1-4 hours each time, filter the extract at 80-200 mesh; merge the extract , vacuum concentrated to solid content 5-20% to obtain Grifola frondosa extract concentrate;

   (2) Microfiltration pretreatment is carried out on the extract of Grifola frondosa, the pore size of the microfiltration membrane is 100-400nm, the temperature is controlled at 25-60°C, and the operating pressure is within 1MPa, the microfiltration permeate is collected, and the microfiltration unpermeable liquid is discarded. liquid;

   (3) The microfiltration permeate is subjected to ultrafiltration treatment. The pore size of the ultrafiltration membrane corresponds to the intercepted molecular weight of 1-18KDa, the operating pressure is 0.3-1MPa, and the temperature is controlled at 25-40°C. When the volume of the permeate is 40% of the total volume Stop the ultrafiltration when -75%, keep the ultrafiltration retentate that does not permeate the membrane, and discard the ultrafiltration permeate;

   (4) drying the ultrafiltration retentate, and controlling the moisture content of the powder to be less than 15%, the obtained dry powder is the Grifola frondosa polysaccharide.
2. The extraction method of a kind of Grifola frondosa active polysaccharide according to claim 1, is characterized in that, comprises:

   (1) add water 10-25 times the weight of the raw material to the Grifola frondosa fruiting body raw material, extract 2-3 times at 95-105 ° C, extract 1-2 hours each time, filter the extract at 100-200 mesh; merge the extract , vacuum concentrated to solid content 10-18% to obtain Grifola frondosa extract concentrate;

   (2) Perform microfiltration pretreatment on the extract of Grifola frondosa, the pore size of the microfiltration membrane is 100-200 nm, the temperature is controlled at 25-55 °C, and the operating pressure is within 0.8 MPa, the microfiltration permeate is collected, and the microfiltration untreated permeate;

   (3) The microfiltration permeate is subjected to ultrafiltration treatment, the pore size of the ultrafiltration membrane corresponds to the intercepted molecular weight of 2-15KDa, the operating pressure is 0.3-0.6MPa, and the temperature is controlled at 25-35°C. When the volume of the permeate is 55% of the total volume %-75%, stop the ultrafiltration, keep the ultrafiltration retentate that does not pass through the membrane, and discard the ultrafiltration permeate;

   (4) drying the ultrafiltration retentate, and controlling the moisture content of the powder to be less than 12%, the obtained dry powder is the Grifola frondosa polysaccharide.
3. An industrialized method for extracting active polysaccharide from Grifola frondosa, characterized in that it comprises:

   (1) Put the Grifola frondosa fruit body raw material into the extraction tank, add water 10-40 times the weight of the raw material, extract 1-4 times at 80-105 ° C, extract 1-4 hours each time, pass the extract through the filter, The aperture of the filter screen is 80-200 meshes; the extracts are combined and concentrated in vacuo to a solid content of 5-20% to obtain the Grifola frondosa extraction concentrate;

   (2) Introduce the extract concentrate of Grifola frondosa into the microfiltration equipment for pretreatment, the pore size of the microfiltration membrane is 100-400nm, the temperature is controlled at 25-60°C, and the operating pressure is within 1MPa, the microfiltration permeate is collected, and the microfiltration is discarded. no permeate;

   (3) The microfiltration permeate is introduced into the ultrafiltration equipment, and the polysaccharides of different molecular weights are intercepted and purified with an ultrafiltration membrane. The pore size of the ultrafiltration membrane corresponds to the intercepted molecular weight of 1-18KDa, the operating pressure is 0.3-1MPa, and the temperature is controlled at 25-40 ℃, when the volume of the permeate is controlled at 40%-75% of the total volume, the ultrafiltration is stopped, the ultrafiltration retentate that does not permeate the membrane is retained, and the ultrafiltration permeate is discarded;

   (4) the ultrafiltration retentate is dried, and the moisture content of the finished powder is controlled to be less than 15%, and the obtained dry powder is the Grifola frondosa polysaccharide finished product.
4. The extraction method of industrialized Grifola frondosa active polysaccharide according to claim 3, is characterized in that, comprises:

   (1) put the Grifola frondosa fruit body raw material into the extraction tank, add 10-25 times of water of the raw material weight, extract 2-3 times at 95-105 ° C, extract 1-2 hours each time, and pass the extract through the filter screen, The pore size of the filter screen is 100-200 mesh; the extracts are combined and concentrated in vacuo to a solid content of 10-18% to obtain the Grifola frondosa extraction concentrate;

   (2) Introduce the concentrated liquid of Grifola frondosa extraction into the microfiltration equipment for pretreatment, the microfiltration membrane pore size is 100-200nm, the temperature is controlled at 25-55°C, and the operating pressure is within 0.8MPa, the microfiltration permeate is collected, and the microfiltration permeate is discarded. Filter the permeate;

   (3) The microfiltration permeate is introduced into the ultrafiltration equipment, and the polysaccharides of different molecular weights are intercepted and purified by the ultrafiltration membrane. The pore size of the ultrafiltration membrane corresponds to the intercepted molecular weight of 2-15KDa, the operating pressure is 0.3-0.6MPa, and the temperature is controlled at 25-35 ℃, when the volume of the permeate is controlled at 55%-75% of the total volume, the ultrafiltration is stopped, the ultrafiltration retentate that does not permeate the membrane is retained, and the ultrafiltration permeate is discarded;

   (4) drying the ultrafiltration retentate, and controlling the moisture content of the finished powder to be less than 12%, the obtained dry powder is the finished product of Grifola frondosa polysaccharide.
5. The extraction method according to any one of claims 1-4, wherein the drying of the ultrafiltration retentate comprises: one or more of spray drying, freeze drying, vacuum drying or atmospheric drying methods .
6. The extraction method according to any one of claims 1-4, wherein the microfiltration membrane material is one or more of a ceramic membrane, an organic polymer membrane, and a metal membrane.
7. The extraction method according to any one of claims 1-4, wherein the pore size of the ultrafiltration membrane is less than 100 nm, the molecular weight cut-off range is 1-18KDa, and the ultrafiltration membrane material is ceramic membrane, organic polymer membrane, metal one or more of the membranes.
8. A Grifola frondosa polysaccharide obtained by the extraction method according to any one of claims 1-7.
9. The use of the Grifola frondosa active polysaccharide according to claim 8 in the preparation of a hypoglycemic medicament.

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