A method for removing protein from boletus luridus polysaccharide

Abstract

The application provides a method for removing protein from Boletus aereus polysaccharide, which comprises the following steps: crushing Boletus aereus fruiting bodies, adding an ethanol-ammonium sulfate aqueous two-phase system, and performing ultrasonic extraction; after standing and separation, collecting the water phase, concentrating, adding an ethanol solution, standing, centrifuging, taking the precipitate, and performing freeze-drying to obtain crude Boletus aereus polysaccharide; and performing deproteinization treatment on the crude Boletus aereus polysaccharide by using a cation exchange resin, collecting the eluent, concentrating, adding an ethanol solution, standing, centrifuging, taking the precipitate, and performing freeze-drying to obtain deproteinized Boletus aereus polysaccharide. The method for removing protein from Boletus aereus polysaccharide by using the ethanol-ammonium sulfate aqueous two-phase system for ultrasonic extraction in combination with the 732 cation exchange resin method has the advantages that the deproteinization rate of the extracted Boletus aereus polysaccharide is high, the polysaccharide retention rate is also high, the in-vitro activity of the polysaccharide is improved, and the method provides a research basis for in-depth development and utilization of Boletus aereus fungal resources to prepare functional food.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of active substance extraction, in particular to a deproteinization method of Phlebopus portentosus polysaccharide. BACKGROUND

[0002] Phlebopus portentosus, also known as Phlebopus portentosus, is also called strange Phlebopus portentosus. Phlebopus portentosus is widely distributed in Malaysia, China, Australia, Thailand and Mexico. Its fruiting body contains various amino acids, alkaloids, phenolic acids, terpenes, vitamins, sterols and sugars. Polysaccharide is a kind of natural biological macromolecule with high nutritional value. Due to the unique biological activity of polysaccharide, it has become a research hotspot in recent years. However, the extracted polysaccharide components often contain impurities such as pigments and proteins, which interfere with the structure determination and biological activity research of polysaccharide. Therefore, it is very important to use a deproteinization method that is efficient, low-polluting and does not destroy the structure and activity of polysaccharide. In recent years, domestic and foreign research on Phlebopus portentosus mainly focuses on biological characteristics, artificial cultivation and nutrition, quality evaluation and identification, and medicinal value. In the research on the active ingredients of Phlebopus portentosus, phenolic acids, crude polysaccharide, polysaccharide-protein complex and pyrrole alkaloids are mainly included. At present, there is little research on the deproteinization process of polysaccharide in Phlebopus portentosus fruiting body. The research on the deproteinization process of polysaccharide in Phlebopus portentosus fruiting body can provide a research basis for the further development and utilization of Phlebopus portentosus fungal resources to prepare functional food. SUMMARY

[0003] In view of this, the purpose of the present application is to provide a deproteinization method of Phlebopus portentosus polysaccharide, to screen out the best deproteinization method of Phlebopus portentosus polysaccharide, and to provide a research basis for the further separation and purification of Phlebopus portentosus polysaccharide and the development of functional food.

[0004] The technical scheme of the present application is as follows:

[0005] A deproteinization method of Phlebopus portentosus polysaccharide, comprising the following steps:

[0006] (1) Extraction: crushing Phlebopus portentosus fruiting body, adding ethanol-ammonium sulfate aqueous two-phase system, ultrasonic extraction for 30-50 min, standing and separating, collecting the water phase, concentrating, adding ethanol solution, standing, centrifuging, taking the precipitate for freeze-drying, and obtaining Phlebopus portentosus crude polysaccharide;

[0007] The mass concentration of ethanol in the ethanol-ammonium sulfate aqueous two-phase system is 16-20%, and the mass concentration of ammonium sulfate is 30-35%;

[0008] (2) Deproteinization: the crude polysaccharide solution obtained in step (1) is prepared, and deproteinization treatment is performed on the crude polysaccharide solution by using a cation exchange resin, the elution flow rate of the crude polysaccharide solution is controlled to be 200-250 mL / min, and distilled water is used for elution, the eluate is collected, concentrated, ethanol solution is added, and then the mixture is allowed to stand, centrifuged, and the precipitate is freeze-dried to obtain deproteinized polysaccharide of Phlebopus portentosus.

[0009] Further, in step (1), the power of ultrasonic extraction is 400-500 W, and the water bath temperature of ultrasonic extraction is 30-40℃.

[0010] Further, in step (1), the ratio of the mass of Phlebopus portentosus fruiting bodies to the volume of the ethanol-ammonium sulfate aqueous two-phase system is 1 g: 25-30 mL.

[0011] Further, in step (2), the pH value of the crude polysaccharide solution is 7.0-8.0.

[0012] Further, the mass concentration of the crude polysaccharide solution is 8-12 mg / mL.

[0013] Further, in step (2), the ratio of the diameter to the height of the resin is 1: 3-5, and 4-5 times the column volume of distilled water is used for elution.

[0014] Further, in step (2), the concentrated extract has a relative density of 1.2-1.3 at 60-65℃ under reduced pressure.

[0015] Further, in step (2), when the crude polysaccharide solution is loaded onto the resin, it also includes standing and adsorbing for 1-3 h.

[0016] Further, the present application provides the polysaccharide of Phlebopus portentosus obtained by the above-mentioned deproteinization method.

[0017] Further, the present application provides the polysaccharide of Phlebopus portentosus obtained by the above-mentioned deproteinization method, and the deproteinization rate of the polysaccharide of Phlebopus portentosus is greater than 88%, and the polysaccharide retention rate is greater than 85%.

[0018] Compared with the prior art, the present application has the following beneficial effects:

[0019] The present application uses an ethanol-ammonium sulfate aqueous two-phase system for ultrasonic extraction combined with a 732 cation exchange resin method for deproteinization, and the polysaccharide of Phlebopus portentosus obtained by extraction has a high deproteinization rate and a high polysaccharide retention rate, and the in vitro activity of the polysaccharide is improved, which provides a research basis for the in-depth development and utilization of Phlebopus portentosus fungal resources to prepare functional foods.

[0020] The ethanol-ammonium sulfate aqueous two-phase system ultrasonic-assisted extraction method provided by the present application is suitable for extracting Boletus aereus polysaccharide, can effectively maintain the activity and conformation of polysaccharide substances, and is helpful to improve the deproteinization efficiency of the subsequent 732 cation exchange resin method, and has mild operation conditions and high efficiency.

[0021] The ethanol-ammonium sulfate aqueous two-phase system ultrasonic extraction combined with the 732 cation exchange resin method is adopted in the present application, the Boletus aereus polysaccharide obtained by extraction has good in-vitro activity and good antioxidant capacity, and the in-vitro activity is improved. DETAILED DESCRIPTION

[0022] In order to better understand the technical content of the present application, specific examples are provided below to further illustrate the present application.

[0023] The experimental methods used in the embodiments of the present application are conventional methods unless otherwise specified.

[0024] The materials, reagents and the like used in the embodiments of the present application can be obtained from commercial channels unless otherwise specified.

[0025] The Boletus aereus fruiting body is purchased from Xishuangbanna Dai Autonomous Prefecture, Yunnan, and is identified by Professor Zeng Niankai of the School of Pharmacy, Hainan Medical College as the fruiting body of the fungus Phlebopus portentosus of the small boletus family and the vein boletus genus.

[0026] Example 1 - Deproteinization process of Boletus aereus crude polysaccharide

[0027] (1) Extraction test

[0028] The Boletus aereus polysaccharide sample subjected to ultrasonic extraction and deproteinization by using the ethanol-ammonium sulfate aqueous two-phase system is prepared as follows: the dried Boletus aereus fruiting body is crushed, the mass concentration of the ethanol solution is adjusted to 16%, the mass concentration of the ammonium sulfate is adjusted to 34%, and the solid-liquid mass / volume ratio is adjusted to 1g:30mL. The ethanol-ammonium sulfate aqueous two-phase system is added to the Boletus aereus fruiting body powder, and the mixture is stirred uniformly. The ultrasonic power is adjusted to 500W, and the water bath temperature is adjusted to 30℃. The mixture is subjected to ultrasonic water bath extraction for 40min. After the ultrasonic extraction is completed, the solution is cooled and separated, and the aqueous phase is collected, filtered, and concentrated to 1 / 3 of the original volume. Then, 4 times the volume of 95% ethanol is added, and the mixture is allowed to stand at 4℃ for 12h. The mixture is centrifuged (3500r / min, 20min), and the precipitate is taken out and subjected to vacuum freeze-drying to obtain Boletus aereus crude polysaccharide.

[0029] (2) Pretreatment of resin

[0030] The resin was first soaked in 2 volumes of distilled water for 24 h, then washed with distilled water until the effluent was clear, then soaked in 1 M NaOH solution for 24 h, washed with distilled water until the effluent was neutral, and finally soaked in 1 M HCI solution for 24 h, and washed with distilled water until the effluent was neutral.

[0031] (3) Deproteinization test

[0032] The cation exchange resin 732 was packed into a column (35 mm x 250 mm) with a resin packing volume of about 2.5 L, a glass resin chromatography column with a diameter of 10 mm, a diameter-height ratio of 1:3, the pH value of the crude polysaccharide solution was adjusted to 8.0, the mass concentration was 10 mg / mL, the crude polysaccharide solution was slowly loaded onto the resin column, and after standing for 2 h of adsorption, the elution flow rate of the crude polysaccharide solution was controlled at 200-250 mL / min, 4 volumes of distilled water were used for elution, the eluate was collected, concentrated under reduced pressure to a relative density of 1.2 (60°C) of the extract, 4 volumes of 95% ethanol solution were added to the extract, and the mixture was stood at 4°C for 12 h, centrifuged (3500 r / min, 20 min), and the precipitate was vacuum freeze-dried to obtain deproteinized dark brown polyporus polysaccharide.

[0033] Test Example 1 - Extraction process

[0034] Determination of polysaccharide: The content of polysaccharide was determined by the phenol-sulfuric acid method, a glucose standard solution with a concentration of 0.1 mg / mL was prepared to draw a glucose standard curve; 0.1 mL of polysaccharide extract was taken, water was added to make up to 2 mL, and the phenol-sulfuric acid method was used for color development, the absorbance was measured at 490 nm, and the concentration of polysaccharide in the test solution (mg / mL) was calculated by the standard curve to determine the yield of polysaccharide (%):

[0035] Polysaccharide yield (mg / g) = C x V1 x V2 / (m x V3) x 100%

[0036] Note: C is the polysaccharide concentration of the sample (mg / mL); V1 is the volume of the extract (mL); V2 is the volume of the sample solution after dilution (mL); m is the mass of the sample (g); V3 is the sample volume.

[0037] According to the extraction process of the aqueous two-phase system in Example 1, the results are as follows:

[0038] Table 1 Extraction results of the aqueous two-phase system

[0039] Item Polysaccharide yield (mg / g) Sample 1 16.8 Sample 2 16.7 Sample 3 17.5 Sample 4 17.0 Sample 5 17.2 Average 17.0

[0040] From Table 1 above, it can be seen that the polysaccharide yield of dark brown polyporus polysaccharide extracted by ultrasonic extraction using the ethanol-ammonium sulfate aqueous two-phase system in Example 1 is an average of 17.0 mg / g.

[0041] Test Example 2 - Deproteinization Process

[0042] Determination of polysaccharide: The content of polysaccharide was determined by phenol-sulfuric acid method, a glucose standard solution with a concentration of 0.1 mg / mL was prepared to draw a glucose standard curve; 0.1 mL of polysaccharide solution with a concentration of 1 mg / mL was taken, water was added to make up to 2 mL, and coloration was performed by phenol-sulfuric acid method, the absorbance was determined at 490 nm, and the mass m (mg) of glucose in the test solution was calculated through the standard curve, the mass of polysaccharide before and after treatment of the crude polysaccharide solution was determined, and the polysaccharide retention rate was calculated by the formula:

[0043] Polysaccharide retention rate (%) = m 后 / m 前 x 100%

[0044] Note: m 前 is the mass of polysaccharide before treatment (mg); m 后 is the mass of polysaccharide after treatment (mg).

[0045] Determination of protein content: The content of protein was determined by Coomassie brilliant blue method, a bovine serum albumin standard solution with a concentration of 0.1 mg / mL was prepared to draw a bovine serum albumin standard curve; 1 mL of polysaccharide solution with a concentration of 1 mg / mL was taken, coloration was performed by Coomassie brilliant blue method, the absorbance was determined at 595 nm, the mass m (mg) of protein in the test solution was calculated through the standard curve, the mass of protein before and after treatment of the crude polysaccharide solution was determined, and the deproteinization rate was calculated by the formula:

[0046] Deproteinization rate (%) = (m 前 -m 后 ) / m 前 x 100%

[0047] Note: m 前 is the mass of protein before treatment (mg); m 后 is the mass of protein after treatment (mg).

[0048] According to the deproteinization process of the cation exchange resin method in Example 1, the results are as follows:

[0049] Table 2 Deproteinization results of resin treatment

[0050] Item Deproteinization rate (%) Polysaccharide retention rate (%) Sample 1 90.12 86.51 Sample 2 89.21 86.42 Sample 3 89.75 87.17 Sample 4 88.87 85.77 Sample 5 89.07 86.60 Average 89.40 86.50

[0051] From Table 2 above, it can be seen that the deproteinization process of Example 1 using 732 cation exchange resin method has a high removal rate of protein, with an average value of 89.40%, and the average value of polysaccharide retention rate is 86.50%, and the deproteinization rate of each sample is 88.87% to 90.12%, and the polysaccharide retention rate is 85.77% to 87.17%, the deproteinization process of 732 cation exchange resin method is stable, and the quality of the obtained samples is consistent.

[0052] Test Example 3 - Activity Assay

[0053] DPPH radical scavenging assay: The dark brown vein polyporus polysaccharide was prepared into a sample with a mass concentration of 10 mg / mL, mixed with an equal amount of DPPH solution (0.16 mM prepared with anhydrous ethanol), mixed quickly, reacted for 30 min at room temperature in the dark, measured the absorbance value at 517 nm, anhydrous ethanol was used as a blank control, and the DPPH radical scavenging rate was calculated by the formula:

[0054] DPPH radical scavenging rate (%) = [1-(A0-A1) / A2] x 100%

[0055] Note: A0 is the absorbance value of the sample; A1 is the absorbance value of the sample and anhydrous ethanol; A2 is the absorbance value of the blank control.

[0056] According to the dark brown vein polyporus polysaccharide decolorization method of Chinese patent CN117186262A, the combined use method of HPD-100 macroporous adsorption resin method and polyamide column chromatography method is selected, and the polysaccharide sample obtained by extraction is used as a comparative sample, wherein the amount of macroporous resin is 50%, the oscillation time is 6.3 h, the adsorption temperature is 75°C, the adsorption time of polyamide column chromatography method is 4 h, the amount of polyamide is 12%, and the sample concentration is 3 mg / mL.

[0057] According to the process of Example 1, the results are as follows:

[0058] Table 3 DPPH radical scavenging rate results

[0059] Item Removal rate (%) Sample 1 75.7 Sample 2 77.0 Sample 3 80.2 Sample 4 76.8 Sample 5 78.6 Average 77.7 Comparative sample 65.6

[0060] From Table 3 above, it can be seen that the dark brown vein polyporus polysaccharide obtained by the ethanol-ammonium sulfate aqueous two-phase system ultrasonic extraction combined with the 732 cation exchange resin method for deproteinization in Example 1 has a high DPPH radical scavenging rate, and the average value of the scavenging rate is 77.7%, which is better than the comparative sample, indicating that the ethanol-ammonium sulfate aqueous two-phase system ultrasonic extraction method and the 732 cation exchange resin method have good deproteinization effect on the dark brown vein polyporus polysaccharide, and the dark brown vein polyporus polysaccharide obtained by extraction has good antioxidant capacity and improved in vitro activity.

[0061] Example 2 - Concentration investigation of extraction test

[0062] The ethanol-ammonium sulfate aqueous two-phase system is used for ultrasonic extraction of deproteinized polysaccharide samples of Boletus aereus, the dried Boletus aereus fruiting body is crushed, the mass concentration of ethanol solution is adjusted, the mass concentration of ammonium sulfate is adjusted, 1 g:30 mL of the material liquid mass volume ratio is used, the ethanol-ammonium sulfate aqueous two-phase system is added into the Boletus aereus fruiting body powder, and the mixture is fully stirred and uniformly mixed, the ultrasonic power is adjusted to 500 W, the water bath temperature is 30 DEG C, and the ultrasonic water bath extraction is performed for 40 min, after the ultrasonic extraction, the solution is cooled and separated, the water phase is collected, filtered, concentrated to 1 / 3 of the original volume, 4 times the volume of 95% ethanol is added, the mixture is placed at 4 DEG C for 12 h, centrifuged (3500 r / min, 20 min), and the precipitate is taken out and vacuum freeze-dried to obtain the crude polysaccharide of Boletus aereus.

[0063] Table 4 extraction results of different aqueous two-phase system concentrations

[0064] Ethanol mass concentration (%) Ammonium sulfate mass concentration (%) Polysaccharide yield (mg / g) 16 34 17.0 18 32 15.7 20 30 16.5 22 28 14.8 24 26 13.4

[0065] From the above table 4, with the increase of the mass concentration of ethanol, the mass concentration of ammonium sulfate is reduced, and the yield of polysaccharide is gradually reduced.

[0066] Example 3 - investigation of the material liquid ratio of the extraction test

[0067] The ethanol-ammonium sulfate aqueous two-phase system is used for ultrasonic extraction of deproteinized polysaccharide samples of Boletus aereus, the dried Boletus aereus fruiting body is crushed, the mass concentration of ethanol solution is adjusted, the mass concentration of ammonium sulfate is adjusted, 1 g:30 mL of the material liquid mass volume ratio is used, the ethanol-ammonium sulfate aqueous two-phase system is added into the Boletus aereus fruiting body powder, and the mixture is fully stirred and uniformly mixed, the ultrasonic power is adjusted to 500 W, the water bath temperature is 30 DEG C, and the ultrasonic water bath extraction is performed for 40 min, after the ultrasonic extraction, the solution is cooled and separated, the water phase is collected, filtered, concentrated to 1 / 3 of the original volume, 4 times the volume of 95% ethanol is added, the mixture is placed at 4 DEG C for 12 h, centrifuged (3500 r / min, 20 min), and the precipitate is taken out and vacuum freeze-dried to obtain the crude polysaccharide of Boletus aereus.

[0068] Table 5 extraction results of different material liquid ratio aqueous two-phase systems

[0069] Mass volume ratio of feed solution Polysaccharide yield (mg / g) 1 g: 20 mL 16.8 1 g: 30 mL 17.3 1 g: 40 mL 15.2

[0070] From the above table 5, the material liquid mass volume ratio of 1 g:30 mL has a higher polysaccharide yield.

[0071] Example 4 - investigation of the ultrasonic conditions of the extraction test

[0072] The ethanol-ammonium sulfate aqueous two-phase system is used for ultrasonic extraction of deproteinized polysaccharide sample of Boletus aereus. The dried Boletus aereus fruiting body is crushed, the mass concentration of ethanol solution is adjusted to 16%, the mass concentration of ammonium sulfate is adjusted to 34%, the mass volume ratio of solid to liquid is 1 g:30 mL, the ethanol-ammonium sulfate aqueous two-phase system is added into the Boletus aereus fruiting body powder, and the mixture is stirred uniformly, the ultrasonic power and water bath temperature are adjusted, and then ultrasonic water bath extraction is carried out. After the ultrasonic extraction, the solution is cooled and separated, the water phase is collected, filtered, concentrated to 1 / 3 of the original volume, 4 times the volume of 95% ethanol is added, and the mixture is placed at 4°C for 12 hours, centrifuged (3500 r / min, 20 min), and the precipitate is vacuum freeze-dried to obtain the crude polysaccharide of Boletus aereus.

[0073] Table 6: Extraction results of different ultrasonic conditions of aqueous two-phase system

[0074] Power (W) Temperature (℃) Time (min) Polysaccharide yield (mg / g) 400 30 30 15.6 400 30 30 17.5 400 40 40 16.6 400 50 40 16.0 500 40 40 17.7 500 50 50 14.7 600 30 30 13.2

[0075] From the above table 6, it can be seen that when the ultrasonic power is 400-500 W, the temperature is 30-40°C, and the ultrasonic time is 30-40 min, the polysaccharide yield is relatively high.

[0076] Example 5: Investigation of deproteinization conditions

[0077] The cation exchange resin 732 is packed into a column (35 mm x 250 mm) with a resin packing volume of about 2.5 L. A glass resin chromatography column with a diameter of 10 mm is used. The crude polysaccharide solution prepared in step (1) of Example 1 is adjusted to a pH value of 10 mg / mL, and then slowly added onto the resin column. The elution flow rate of the crude polysaccharide solution is controlled, and 4 times the volume of distilled water is used for elution. The eluate is collected, concentrated under reduced pressure to a relative density of 1.2 (60°C), 4 times the volume of 95% ethanol solution is added, and the mixture is placed at 4°C for 12 hours. The mixture is centrifuged (3500 r / min, 20 min), and the precipitate is vacuum freeze-dried to obtain the deproteinized polysaccharide of Boletus aereus.

[0078] Table 7: Deproteinization results of different resin treatment conditions

[0079] Diameter-height ratio pH value Standing adsorption (h) Elution flow rate (mL / min) Deproteinization rate (%) Polysaccharide retention rate (%) 1：3 7.0 - 200～250 87.06 86.87 1：3 7.0 2 200～250 89.41 86.52 1：3 8.0 4 200～250 85.48 89.26 1：3 7.0 2 300～350 85.17 84.58 1：5 7.0 2 300～350 86.11 81.60 1：5 7.0 2 200～250 89.07 86.60 1：7 7.0 2 200～250 88.73 80.16

[0080] From the above table 7, it can be seen that when the diameter-height ratio increases, the removal rate of protein increases relatively, but the retention rate of polysaccharide decreases significantly. Standing adsorption for 2 hours helps to improve the deproteinization rate, and increasing the elution flow rate reduces the deproteinization rate, which reduces the adsorption time of the resin and protein.

[0081] The above merely provides the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A method for deproteinization of a Boletus aereus polysaccharide, characterized by, It comprises the following steps: (1) Extraction: crushing the Boletus aereus fruiting body, adding an ethanol-ammonium sulfate aqueous two-phase system, and performing ultrasonic extraction for 30-50 min; after separation, the water phase is collected, concentrated, ethanol solution is added, and then it is left to stand, centrifuged, and the precipitate is freeze-dried to obtain the Boletus aereus crude polysaccharide; In the ethanol-ammonium sulfate aqueous two-phase system, the mass concentration of ethanol is 16-20%, and the mass concentration of ammonium sulfate is 30-35%. (2) Deproteinization: the Boletus aereus crude polysaccharide obtained in step (1) is prepared into a crude polysaccharide solution, and deproteinization treatment is performed using cation exchange resin 732, the elution flow rate of the crude polysaccharide solution is controlled to be 200-250 mL / min, and distilled water is used for elution; the eluate is collected, concentrated, ethanol solution is added, left to stand, centrifuged, and the precipitate is freeze-dried to obtain the deproteinized Boletus aereus polysaccharide.

2. A method of deproteinization of a Boletus aereus polysaccharide according to claim 1, characterized in that, In step (1), the ultrasonic extraction power is 400-500 W, and the water bath temperature is 30-40 ℃.

3. A method of deproteinization of a Boletus aereus polysaccharide according to claim 1, characterized in that, In step (1), the solid-liquid mass volume ratio of the Boletus aereus fruiting body and the ethanol-ammonium sulfate aqueous two-phase system is 1 g:25-30 mL.

4. A method of deproteinization of a Boletus aereus polysaccharide according to claim 1, characterized in that, In step (2), the pH value of the crude polysaccharide solution is 7.0-8.

0.

5. A method of deproteinization of a Boletus aereus polysaccharide according to claim 1, characterized in that, The mass concentration of the crude polysaccharide solution is 8-12 mg / mL.

6. A method of deproteinization of a Boletus aereus polysaccharide according to claim 1, characterized in that, In step (2), the diameter-height ratio of the resin is 1:3-5, and 4-5 times the column volume of distilled water is used for elution.

7. A method of deproteinization of a Boletus aereus polysaccharide according to claim 1, characterized in that, In step (2), the concentrated solution is reduced in pressure to a relative density of 1.2-1.3 at 60-65 ℃.

8. A method of deproteinization of a Boletus aereus polysaccharide according to claim 1, characterized in that, In step (2), when the crude polysaccharide solution is loaded onto the resin, it also includes standing for 1-3 h.

9. The Boletus aereus polysaccharide obtained by the deproteinization method according to any one of claims 1-8.

10. The Boletus aereus polysaccharide according to claim 9, characterized in that, The deproteinization rate of the Boletus aereus polysaccharide is greater than 88%, and the polysaccharide retention rate is greater than 85%.