Allium fistulosum bolete polysaccharide as well as preparation method and application thereof

Abstract

The invention discloses allium fistulosum and bolete polysaccharide as well as a preparation method and application thereof. The allium fistulosum and bolete polysaccharide is a glycopolymer composed of arabinose, xylose, mannose, glucose and galactose. The allium fistulosum bolete polysaccharide disclosed by the invention has strong antioxidant capacity, has a stimulation and activation effect on macrophage immune response, has an inhibition effect on alpha-glucosidase, has the effects of resisting oxidation, enhancing immunity and reducing blood sugar, and can be applied to development of health-care foods and functional foods.

Description

Technical Field

[0001] The present invention relates to the field of pharmaceutical technology, and particularly relates to a polysaccharide from Butyriboletus roseoflavus, a preparation method thereof, and an application thereof. Background Art

[0002] As a natural active ingredient, fungal polysaccharide has various activities such as anti-tumor, antioxidant, anticoagulant, and immunomodulatory activities, and has the characteristics of being safe and non-toxic, and has great potential for development into functional foods or health products in the future.

[0003] The extraction method of fungal polysaccharide will affect the yield of fungal polysaccharide, and will also affect the structure and activity of the extracted polysaccharide. The crude fungal polysaccharide obtained by extraction often contains impurities such as proteins and pigments, and purified polysaccharide components can be obtained only after removing them by different methods. The structure of polysaccharide will also affect the active function of polysaccharide. On the basis of correctly analyzing the polysaccharide structure, the structure-activity relationship of polysaccharide can be better understood.

[0004] Butyriboletus roseoflavus, also known as Butyriboletus roseoflavus, Butyriboletus flavipes, belongs to Agaricomycetes, Basidiomycota, Boletales, Boletaceae, and grows between 900 and 2200 meters above sea level in the pine-oak mixed forest in Yunnan and Sichuan. Some studies have shown that Butyriboletus roseoflavus has a relatively high crude protein content (46.20 g / 100 g dry weight), crude fiber 15%, crude fat 2%, soluble sugar 9.6%, and the ratio of essential amino acids to non-essential amino acids (E / N) is 0.68, and the ratio of essential amino acids to total amino acids > 40%, meeting the standard of FAO high-quality protein source. However, there is no report on the polysaccharide of Butyriboletus roseoflavus. Summary of the Invention

[0005] The present invention aims to at least solve one of the above technical problems in the prior art. For this reason, the purpose of the present invention is to provide a polysaccharide from Butyriboletus roseoflavus, a preparation method thereof, and an application thereof.

[0006] In order to achieve the above purpose, the technical solutions adopted by the present invention are as follows:

[0007] In the first aspect of the present invention, there is provided a polysaccharide from Butyriboletus roseoflavus, which is a sugar polymer composed of arabinose, xylose, mannose, glucose, and galactose.

[0008] In some embodiments of the present invention, the molar ratio of arabinose, xylose, mannose, glucose and galactose is 1.00:(0.20 - 0.30):(1.40 - 1.70):(2.30 - 2.50):(3.80 - 4.10); such as 1.00:(0.23 - 0.27):(1.55 - 1.59):(2.40 - 2.45):(3.90 - 4.00), 1.00:0.25:1.57:2.42:3.96.

[0009] In some embodiments of the present invention, the Boletus impolitus polysaccharide comprises the following sugar residues: T-Glcp, T-Galp, 1,4-Glcp, 1,3-Galp, 1,2-Glcp and 1,4-Galp.

[0010] In some embodiments of the present invention, the molar percentages of T-Glcp, T-Galp, 1,4-Glcp, 1,3-Galp, 1,2-Glcp and 1,4-Galp are 12.50% - 13.50%, 5.0% - 5.5%, 13.00% - 14.00%, 17.00% - 18.50%, 57.00% - 58.00% and 16.00% - 17.10% respectively; such as 12.90% - 13.10%, 5.1% - 5.3%, 13.50% - 13.90%, 17.50% - 17.90%, 57.20% - 57.90% and 16.50% - 17.00%; 13.03 ± 0.2%, 5.2 ± 0.2%, 13.75 ± 0.2%, 17.68 ± 0.2%, 57.55 ± 0.2% and 16.79 ± 0.2%; 13.03%, 5.2%, 13.75%, 17.68%, 57.55% and 16.79%.

[0011] In some embodiments of the present invention, the structural fragment of the Boletus impolitus polysaccharide is as shown in Formula I:

[0012]

[0013] In some embodiments of the present invention, the Boletus impolitus polysaccharide comprises 68 - 71 wt% of total sugar, 2.0 - 3.2 wt% of protein and 2.7 - 2.9 wt% of uronic acid, such as 69 - 70 wt% of total sugar, 2.9 - 3.1 wt% of protein and 2.75 - 2.85 wt% of uronic acid; 69.74 wt% of total sugar, 3.09 wt% of protein and 2.81 wt% of uronic acid.

[0014] In some embodiments of the present invention, the weight-average molecular weight of the polysaccharide from Boletus impolitus is 8,000 - 30,000 Da; such as 10,000 - 25,000 Da, 12,000 - 20,000 Da, 14,000 - 15,000 Da, 14,500 - 14,900 Da, 14,800 - 14,850 Da, 14,835 ± 10 Da, 14,835 Da.

[0015] The second aspect of the present invention provides a method for preparing the polysaccharide from Boletus impolitus as described above, comprising the following steps:

[0016] S1: The fruiting body powder of Boletus impolitus is subjected to water extraction, the extract is concentrated, and the supernatant is decolorized, deproteinized, and precipitated with alcohol to obtain the crude polysaccharide from Boletus impolitus.

[0017] S3: After the crude polysaccharide from Boletus impolitus is eluted by a chromatography column, the eluate is concentrated, dialyzed, and freeze-dried to obtain the polysaccharide from Boletus impolitus as described above.

[0018] In some embodiments of the present invention, in S1, the mass-volume ratio of the fruiting body powder of Boletus impolitus to water is 1:(10 - 30) g / mL; such as 1:10 g / mL, 1:15 g / mL, 1:20 g / mL, 1:25 g / mL, 1:30 g / mL.

[0019] In some embodiments of the present invention, in S1, the temperature of water in the water extraction is 75°C - 95°C; such as 75°C, 80°C, 85°C, 90°C, 95°C; the time of the water extraction is 60 min - 180 min; such as 60 min, 90 min, 120 min, 150 min, 180 min.

[0020] In some embodiments of the present invention, in S1, the decolorization is carried out using macroporous resin; for example, a macroporous resin solution of 1.0 - 1.5 g / mL (such as 1.2 g / mL) is mixed with the supernatant in a volume ratio of 1:0.8 - 1.2 (such as 1:1) for decolorization; the macroporous resin includes macroporous resin D354FD; the time of decolorization is 1 - 3 h (such as 2 h); the deproteinization is carried out using Sevag reagent; the Sevag reagent includes n-butanol and chloroform; the volume ratio of n-butanol to chloroform is 1:3 - 5 (such as 1:4); the volume ratio of the supernatant to Sevag reagent is 1:3 - 5 (such as 1:4).

[0021] In some embodiments of the present invention, in S1, the alcohol precipitation is carried out using an ethanol solution; the volume concentration of the ethanol solution is 90 - 98% (such as 92 - 97%, 95%); the volume ratio of the supernatant to the ethanol solution is 1:3 - 5 (such as 1:4).

[0022] In some embodiments of the present invention, in S2, the chromatography column includes an ion exchange chromatography column; the packing material of the ion exchange chromatography column includes cellulose packing material (such as DEAE-52 cellulose packing material).

[0023] In some embodiments of the present invention, in S2, the eluent used for eluting the chromatography column includes a 0 - 0.1 mol / L NaCl solution (such as 0, 0.01 mol / L, 0.02 mol / L, 0.05 mol / L, 0.08 mol / L, 0.1 mol / L).

[0024] In some embodiments of the present invention, in S2, the dialysis is carried out using a dialysis bag with a molecular weight cut-off of 3500 - 8000 Da (such as 3500 Da, 5000 Da, 6000 Da, 8000 Da).

[0025] In the third aspect of the present invention, a composition is provided, which includes the polysaccharide from Boletus impolitus described above.

[0026] In some embodiments of the present invention, the composition includes any one of a pharmaceutical composition, a health product, and a food product.

[0027] In some embodiments of the present invention, the pharmaceutical composition further includes a pharmaceutically acceptable carrier.

[0028] In the fourth aspect of the present invention, an application of the polysaccharide from Boletus impolitus or the composition in preparing at least one drug for antioxidant, anti-tumor, immune enhancement, and blood sugar reduction is provided.

[0029] The beneficial effects of the present invention are as follows:

[0030] The polysaccharide from Boletus impolitus of the present invention has strong antioxidant ability, can stimulate and activate the immune response of macrophages, has an inhibitory effect on α-glucosidase, and has the functions of antioxidant, immune enhancement, and blood sugar reduction, and can be used for the development of health foods and functional foods. Description of the Drawings

[0031] Figure 1 It is the sugar content curve graph of BRP-I of the present invention.

[0032] Figure 2 It is the ultraviolet scanning spectrum graph of BRP-I of the present invention.

[0033] Figure 3 It is the GPC standard product spectrum graph.

[0034] Figure 4 It is the GPC spectrum graph of BRP-I of the present invention.

[0035] Figure 5This is the FT-IR spectrum of BRP-I of the present invention.

[0036] Figure 6 This is the spectrum of the GC standard.

[0037] Figure 7 This is the GC spectrum of BRP-I of the present invention.

[0038] Figure 8 This is the total ion current chromatogram of BRP-I of the present invention.

[0039] Figure 9 This is the 1 1H NMR spectrum of BRP-I of the present invention.

[0040] Figure 10 This is the 13 13C NMR spectrum of BRP-I of the present invention.

[0041] Figure 11 This is the HSQC spectrum of BRP-I of the present invention.

[0042] Figure 12 This is the HMBC spectrum of BRP-I of the present invention.

[0043] Figure 13 This is the NOESY spectrum of BRP-I of the present invention.

[0044] Figure 14 This is the structural fragment diagram of BRP-I of the present invention.

[0045] Figure 15 This is the SEM scanning electron micrograph of BRP-I of the present invention.

[0046] Figure 16 This shows the effect of BRP-I at different concentrations of the present invention on the release of IL-6 cytokine.

[0047] Figure 17 This shows the effect of BRP-I at different concentrations of the present invention on the release of TNF-α cytokine.

[0048] Figure 18 This shows the ·OH scavenging rate of BRP-I at different concentrations of the present invention.

[0049] Figure 19 This shows the hypoglycemic activity of BRP-I at different concentrations of the present invention. Detailed implementation manners

[0050] The content of the present invention will be further described in detail through specific embodiments below. Unless otherwise specified, the raw materials, reagents or devices used in the examples and comparative examples can be obtained from conventional commercial channels or can be obtained by methods of the prior art. Unless otherwise specified, the test or measurement methods are conventional methods in the art.

[0051] Example 1

[0052] In this example, a polysaccharide BRP-I from Boletus impolitus was prepared. The specific process was as follows:

[0053] S1: Weigh 100 g of dry Boletus impolitus fruit bodies, crush them into powder with a pulverizer, and then pass through an 80-mesh sieve. Mix the fruit body powder with distilled water according to a volume ratio of 1:25 (g:mL), and heat in a water bath at 75 °C for 150 min. Filter out the residue in the extract, and concentrate the supernatant to 200 mL. Mix the supernatant with the macroporous resin D354FD soaked in advance according to a volume ratio of 1:1, and heat in a water bath at 60 °C for 2 h for decolorization. Filter out the macroporous resin from the decolorized crude extract, and use 500 mL of Sevag reagent (n-butanol: chloroform = 1:4, v / v) to remove proteins by centrifugation, and elute with Sevag reagent in a cycle for 3 - 4 times. Concentrate the supernatant after protein removal and then mix it with four volumes of 95% ethanol, collect the precipitate and freeze-dry to obtain the crude polysaccharide BRPs from Boletus impolitus.

[0054] S2: Soak the DEAE-52 packing material in advance, slowly and evenly introduce 100 g of the swollen packing material into the chromatography column, and gently tap the column with an ear bulb to compact the packing material. Open the constant flow pump to the maximum flow rate to degas the packing material. After degassing, redissolve the crude polysaccharide BRPs from Boletus impolitus to 10 mg / mL, spread the polysaccharide solution above the packing material, adjust the flow rate to 3 - 4 s / drop, use distilled water (i.e., 0 mol / L NaCl solution) as the elution solution, and collect the eluate. Dialyze the eluate in an 8000 Da dialysis bag using distilled water and freeze-dry to obtain the purified polysaccharide BRP-I from Boletus impolitus.

[0055] Test Example 1

[0056] In this test example, the polysaccharide BRP-I from Boletus impolitus prepared in Example 1 was characterized and tested. The specific process was as follows:

[0057] 1. Sugar content curve: Soak the Sephadex G-75 gel in advance. Pack the column and load the sample in the same way as the DEAE-52 packing material. Use the phenol-sulfuric acid method to detect the eluate in S2, and obtain the sugar content curve. The results are as Figure 1 shown.

[0058] As can be seen from Figure 1 , the sugar content curve is a single symmetric peak shape, indicating that BRP-I has a high purity.

[0059] 2. The physicochemical properties of the Boletus albidus polysaccharide BRP-I prepared in Example 1 were identified. The specific process was as follows:

[0060] The total sugar content was determined to be 69.74% using the phenol-sulfuric acid method;

[0061] The protein content was determined to be 3.09% using the Coomassie brilliant blue method;

[0062] The uronic acid content was determined to be 2.81% using the carbazole-sulfuric acid method;

[0063] The sample solution was scanned using an ultraviolet full-wavelength scanner in the range of 200 - 600 nm. With the wavelength as the abscissa and the OD value as the ordinate, the full-wavelength scanning curve was plotted. The results were as Figure 2 shown. It can be seen that there were small signal peaks near 260 - 280 nm, indicating that there might be a small amount of nucleic acid and polypeptide components.

[0064] 3. The molecular weight of the Boletus albidus polysaccharide BRP-I prepared in Example 1 was determined. The specific process was as follows:

[0065] 3 mg of the Boletus albidus polysaccharide BRP-I sample was dissolved in 1 mL of 20 mmol / L potassium dihydrogen phosphate solution. The instrument used was a Thermo Ultimate 3000 high-performance liquid chromatograph, the detector was a RefractoMax 521 differential refractive index detector, the gel columns were Ultrahydrogel 1000 (7.8×300 mm) and Ultrahydrogel 500 (7.8×300 mm) in series, and the guard column was Ultrahydrogel (6×40 mm). The mobile phase used was 0.02 mol / L potassium dihydrogen phosphate buffer solution, the injection volume was 20 μL, the flow rate was kept constant at 0.8 mL / min, the program for a single sample was run for 35 min, and the column oven temperature was controlled at 35°C. Under these conditions, HPGPC analysis was carried out and compared with the results of the standard product ( Figure 3 ) to obtain a weight-average molecular weight of 14,835 Da for BRP-I ( Figure 4 ).

[0066] 4. Fourier transform infrared spectroscopy analysis of the Boletus albidus polysaccharide BRP-I prepared in Example 1 was carried out. The specific process was as follows:

[0067] 2 mg of BRP-I was weighed, thoroughly mixed with an appropriate amount of KBr powder and ground, and then evenly distributed on the sample stage by the tablet pressing method. Infrared scanning was carried out in the range of 4000 - 500 cm -1 The results were as Figure 5 shown.

[0068] It can be seen that the molecule has a strong and broad absorption peak of -OH stretching vibration at 3445 cm -1 ; the absorption peak at 2928 cm -1 is the stretching vibration peak of C-H in the H–C=O group and CH2, and the peak at 1640 cm-1 is the absorption peak of the symmetric deformation vibration of the polysaccharide carbonyl C=O. The above characteristic absorption peaks indicate that BRP-I is a polysaccharide substance.

[0069] 5. Analyze the monosaccharide composition of the Boletus albocinnamomeus polysaccharide BRP-I prepared in Example 1 by gas chromatography. The specific process is as follows:

[0070] First, BRP-I is subjected to acid hydrolysis and acetyl derivatization, and then detected by gas chromatography (GC). Analyze the monosaccharide composition ( Figure 6 ) by comparing the peak emergence of the monosaccharide standard product ( Figure 7 ). By using the area normalization method, the main monosaccharide composition of BRP-I and its molar ratio are arabinose: xylose: mannose: glucose: galactose = 1.00: 0.25: 1.57: 2.42: 3.96.

[0071] 6. Perform methylation GC-MS analysis on the Boletus albocinnamomeus polysaccharide BRP-I prepared in Example 1. The specific process is as follows:

[0072] Derive the individual component sugars of the polysaccharide into partially methylated glycopyranosyl acetates (PMAAs), and then analyze and quantify them by gas chromatography-mass spectrometry (GC-MS). Compare the total ion current chromatogram ( Figure 8 ) and ion fragments in the MASSBANK database to obtain that BRP-I is mainly composed of six sugar residues: T-Glcp, T-Galp, 1,4-Glcp, 1,3-Galp, 1,2-Glcp, and 1,4-Galp, with molar percentages of 13.03%, 5.2%, 13.75%, 17.68%, 57.55%, and 16.79% respectively.

[0073] 7. Perform methylation GC-MS analysis on the Boletus albocinnamomeus polysaccharide BRP-I prepared in Example 1. The specific process is as follows:

[0074] Weigh 50 mg of BRP-I, dissolve it with 1 mL of D2O, place it in a freeze dryer for lyophilization, and repeat the process of dissolving with D2O and lyophilization 3 times. After the repeated freeze-thaw cycle, dissolve the sample again in 1 mL of D2O, carefully transfer the supernatant to a 5 mm NMR tube, and ensure that the height of the solution in the sample tube is greater than 3.5 cm. Measure the 1 1H NMR ( Figure 9 ), 13 13C NMR ( Figure 10 ), HSQC ( Figure 11 ), HMBC (Figure 12 ) and NOESY( Figure 13 ) spectra.

[0075] 1 Four chemical signals (δ5.32, δ4.99, δ4.91, δ4.45 ppm) are shown in the \(^1H\) spectrum,

[0076] 13 Five chemical signals (δ102.98 ppm, δ102.65 ppm, δ101.45 ppm, δ99.46 ppm and δ97.89 ppm) are shown in the \(^{13}C\) spectrum.

[0077] Six signal cross-peaks appear in the HSQC spectrum of BRP-I. The positions are δ5.32 / 99.46, δ4.99 / 101.45, δ4.91 / 97.88, δ4.99 / 97.88, δ4.45 / 102.65 and δ1.17 / 14.59 respectively, which are attributed to T-α-L-Fucp(A), T-α-D-Glcp(B), 1,3-α-D-Manp(C), 1,6-β-D-Glcp(D), 1,2,6-α-D-Galp(E) respectively. The signal at δ1.17 / 14.59 is the characteristic signal of fucose H6 / C6. Thus, the chemical shifts are obtained as shown in Table 1.

[0078] Table 1 NMR Chemical Shifts of BRP-I

[0079]

[0080] Combined with the HMBC spectrum and the NOESY spectrum, the signal δ4.99 / 78.54 appears in the HMBC spectrum, indicating that H1 of residue B or E is coupled with C2 of residue E, and there is a B1- 2 E linkage or E1- 2 E repeating structure. Similarly, it is inferred that there are also signals δ4.99 / 66.54, δ4.99 / 71.53, δ4.45 / 78.54, δ4.45 / 102.65, δ4.91 / 97.89 in BRP-I, indicating the existence of B1E1- 6 E, B1E1- 6 D, D1- 2 E, D6- 2 E, D6- 1 D, C3 - 1 C, A6- 1 D, etc. linkages. The signal δ4.99 / 3.55 appears in the NOESY spectrum, indicating that H1 of residue B / E is coupled with H3 of residue C, and there is a B / E1- 3The C connection mode. Similarly, based on the presence in NOESY, it is deduced that there are also signals at δ4.45 / 3.55, δ4.91 / 3.78, δ4.99 / 4.99, and δ3.78 / 4.99 in BRP-I, and it is inferred that there are D1- 3 C, C1- 6 D, B1 / E1- 1 E / 1 B, D6- 1 B / 1 E connection mode. Finally, the structural fragment of BRP-I is deduced as follows Figure 14 .

[0081] 8. Conduct a scanning electron microscopy analysis on the Boletus aestivalis polysaccharide BRP-I prepared in Example 1. The specific process is as follows:

[0082] Use tweezers to pick up a small amount of BRP-I and carefully paste it onto the sample stage covered with conductive glue. Use a vacuum sputter coater to coat a conductive layer, and then observe the surface morphology of the Boletus aestivalis polysaccharide at different magnifications of 300 times under an accelerating voltage of 10 kV. The obtained images are as Figure 15 shown. It can be seen that BRP-I has a loose and porous network structure, with tight connections and a soft texture.

[0083] Example 2

[0084] In this example, the immunological activity of the Boletus aestivalis polysaccharide BRP-I was identified. The specific process is as follows:

[0085] Culture RAW264.7 mouse macrophages in a complete medium (DMEM basal medium: double antibodies: fetal bovine serum 90:9:0.5, v / v / v). After culturing for 24 hours, discard the original medium and add BRP-I at a concentration of 100 - 600 μg / mL and continue culturing. After 24 hours, collect the supernatant. When detecting, prepare the standard product according to the Beyotime IL-6 kit, establish a standard curve with the standard product concentration (logarithmic coordinate) as the ordinate and the OD450 value (logarithmic coordinate) as the abscissa. The sample detection includes steps such as adding the sample, incubating at 37°C, washing, and developing color. Finally, measure the absorbance value at 450 nm, and calculate the accumulation amount of IL-6 in the cell supernatant according to the standard curve. The results are as Figure 16 shown. The accumulation amount of IL-6 increases with the increase in the concentration of added BRP-I, showing a significant concentration dependence and a significant difference from the blank control.

[0086] When macrophages are activated, the expression level of tumor necrosis factor TNF-α also shows an increasing trend. The increase in TNF-α can in turn induce the proliferation of other immune cells such as T cells and B cells, ultimately promoting the immune response in a benign manner. According to the instructions of Huamei Bio's mouse tumor necrosis factor TNF-α ELISA kit, the steps of adding samples, incubation, washing, and color development are completed. The release amount of TNF-α after adding BRP-I is detected, and the results are as Figure 17 shown. As the concentration of BRP-I increases, the release amount of cytokines increases, that is, macrophages are activated. It is inferred that BRP-I can stimulate macrophages and thus enhance the immune response.

[0087] Example 3

[0088] In this example, the antioxidant activity of the polysaccharide BRP-I from Boletus impolitus was identified. The specific process is as follows:

[0089] Antioxidants scavenge free radicals by donating electrons through reduction. The stronger the reducing power, the stronger the antioxidant property. As the most oxidizing component among reactive oxygen species (ROS), hydroxyl radicals can initiate lipid peroxidation, protein denaturation, and DNA damage by abstracting hydrogen atoms or electrons. The ability of polysaccharides to scavenge hydroxyl radicals (·OH) is mainly based on the reactive functional groups in their molecular structures and their antioxidant mechanisms.

[0090] Add 50 μL of 9 mM FeSO4 solution and 50 μL of 9 mM salicylic acid solution into a 96-well plate respectively, then add the polysaccharide solution of each component of Boletus impolitus at 2 - 10 mg / mL. After thoroughly mixing with a shaker plate, add 50 μL of H2O2 solution. Place it in an incubator at 37 °C for 30 min, and measure its absorbance at A510. The results are as Figure 18 shown. As the concentration of BRP-I increases, the hydroxyl radical scavenging rate is higher, and the antioxidant ability is enhanced.

[0091] Example 4

[0092] In this example, the hypoglycemic activity of the polysaccharide BRP-I from Boletus impolitus was identified. The specific process is as follows:

[0093] The pNPG method was used to detect the inhibitory effect of Boletus reticuloceps BRP-I on α-glucosidase. Using phosphate buffer with a pH of 6.8 as the solvent, an α-glucosidase solution with a concentration of 1 U / mL and p-nitrophenol with a concentration of 10 mM were prepared, and a 1 M sodium carbonate solution was prepared for later use. 10 μL of the α-glucosidase solution, 40 μL of the phosphate buffer, and 10 μL of the BRP-I solution with a concentration of 1 - 5 mg / mL were added to a 96-well plate respectively, and the mixture was shaken and reacted at 37 °C for 30 min. Then 25 μL of the pNPG solution was added, and the reaction continued at 37 °C for 1 h. Finally, 50 μL of the sodium carbonate solution was added to complete the hydrolysis process. The absorbance A 405 was measured. The results are shown as follows Figure 19 . As shown in the figure, as the concentration of BRP-I increased, the inhibition rate of α-glucosidase became higher, and the potential hypoglycemic activity became stronger. When the concentration of BRP-I reached 5 mg / mL, the glycosidase inhibition rate could reach (85.58 ± 1.35)%.

[0094] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A polysaccharide from Boletus impolitus, characterized in that: A sugar polymer composed of arabinose, xylose, mannose, glucose, and galactose.

2. The Boletus albidus polysaccharide according to claim 1, wherein: The molar ratio of arabinose, xylose, mannose, glucose, and galactose is 1.00:(0.20 - 0.30):(1.40 - 1.70):(2.30 - 2.50):(3.80 - 4.10).

3. The Boletus albicans polysaccharide according to claim 1, wherein: The Boletus aereus polysaccharide includes the following sugar residues: T-Glcp, T-Galp, 1,4-Glcp, 1,3-Galp, 1,2-Glcp, and 1,4-Galp.

4. The Boletus albicans polysaccharide according to claim 1, characterized in that: The structural fragment of the Boletus aereus polysaccharide is shown in Formula I: And / or, the weight-average molecular weight of the polysaccharide from Boletus impolitus is 8,000 to 30,000 Da.

5. The Boletus alboscaber polysaccharide according to claim 1, characterized in that: The Boletus aereus polysaccharide includes 68 - 71 wt% of total sugar, 2.0 - 3.2 wt% of protein, and 2.7 - 2.9 wt% of uronic acid.

6. A method for preparing the polysaccharide of Boletus impolitus described in any one of claims 1 to 5, characterized in that: Including the following steps: S1: The fruiting body powder of Boletus aereus is subjected to water immersion extraction, the extract is concentrated, and the supernatant is decolorized, deproteinized, and alcohol-precipitated to obtain the crude Boletus aereus polysaccharide. S3: After the crude Boletus aereus polysaccharide is eluted by a chromatography column, the eluate is concentrated, dialyzed, and freeze-dried to obtain the Boletus aereus polysaccharide described above.

7. The preparation method of the polysaccharide of Boletus albicans according to claim 6, wherein: The preparation method of the Boletus aereus polysaccharide described above satisfies at least one of the following conditions: (I) In S1, the mass-volume ratio of the fruiting body powder of Boletus aereus to water is 1:(10 - 30) g / mL; (II) In S1, the temperature of water in the water immersion extraction is 75°C - 95°C; (III) In S1, the alcohol precipitation is carried out using an ethanol solution; the volume concentration of the ethanol solution is 90 - 98%; (IV) In S2, the dialysis is carried out using a dialysis bag with a molecular weight cut-off of 3500 - 8000 Da.

8. A composition, characterized in that: Including the Boletus aereus polysaccharide according to any one of claims 1 - 5.

9. The composition according to claim 8, wherein: The composition includes any one of a pharmaceutical composition, a health product, and a food.

10. Use of the Boletus aereus polysaccharide according to any one of claims 1 - 5 or the composition according to claim 8 in the preparation of at least one drug for antioxidant, anti-tumor, immune enhancement, and hypoglycemic effects.

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