Vinasse polysaccharide VPS-30 for resisting ulcerative colitis as well as preparation method and application of vinasse polysaccharide VPS-30
VPS-30, a polysaccharide prepared by hot water extraction and fractional alcohol precipitation, addresses the shortcomings of traditional polysaccharides in the treatment of ulcerative colitis, achieving a highly effective relief of ulcerative colitis and making it suitable for large-scale production and application.
Patent Information
- Application Number
- CN202511267699.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-05
- Publication Date
- 2025-11-18
AI Technical Summary
In the existing technology, there is insufficient research on the bioactivity of distillers' grains polysaccharides in improving ulcerative colitis, which limits their application potential in functional foods and medicines, and there is a lack of efficient extraction processes.
Polysaccharides were extracted from distiller's grains using hot water extraction and then purified by fractional alcohol precipitation to prepare VPS-30, a distiller's grains polysaccharide with a molecular weight of 111.97 kDa. The monosaccharide composition consisted of mannose, glucose, galactose, xylose, arabinose, and galacturonic acid. Its anti-inflammatory activity was used to alleviate ulcerative colitis.
It significantly improves symptoms of ulcerative colitis, reduces colonic shortening and pathological damage, lowers the disease activity index, restores intestinal flora balance, is suitable for large-scale production, and can be administered orally.
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Figure CN120965906A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of biomedical technology, and specifically relates to a wine lees polysaccharide VPS-30 for treating ulcerative colitis, its preparation method, and its application. Background Technology
[0002] Distillers' grains, also known as red lees, fermented grains, or lees, are the solid residue left after the sorghum, wheat, corn, and other raw materials have undergone steaming, fermentation, and distillation to produce alcohol during the brewing process. They are a major byproduct of brewing. my country has a rich baijiu (white liquor) culture, and most regions produce baijiu, such as Guizhou Maotai, Shanxi Fenjiu, and Shaanxi Xifeng, resulting in a massive production of both baijiu and its lees. After fermentation and distillation, the lees retain a high moisture content, making them prone to spoilage. Furthermore, the sheer volume of lees means that if not treated promptly and effectively, it will not only lead to serious environmental problems but also result in a huge waste of usable resources.
[0003] Distillery lees contain abundant polysaccharides with high nutritional value. Current research indicates that distillery lees polysaccharides possess bioactivities such as alleviating alcoholic liver disease, antioxidation, and anti-inflammation, making them a valuable raw material for various functional product developments and possessing significant reuse potential. Despite the abundance of distillery lees polysaccharide resources, related research lags behind. Current studies on the molecular structure of distillery lees polysaccharides are limited, including molecular weight distribution, monosaccharide composition, and glycosidic bond types, severely hindering a deeper understanding of their structure-activity relationships. Secondly, regarding bioactivity research, while polysaccharides generally possess immunomodulatory, anti-inflammatory, antioxidant, and anti-tumor effects, specific bioactivity studies of distillery lees polysaccharides are scarce, particularly regarding their efficacy and mechanism of action in improving ulcerative colitis, which has not been systematically investigated, limiting their application potential in functional foods and pharmaceuticals. To maximize the development and utilization of distillery lees, a highly efficient extraction process for distillery lees polysaccharides is urgently needed in the market. Summary of the Invention
[0004] In view of this, the purpose of this invention is to provide a wine lees polysaccharide VPS-30 for treating ulcerative colitis, its preparation method and application; this invention uses hot water extraction to extract wine lees polysaccharide from wine lees, and uses fractional alcohol precipitation to separate and purify the wine lees polysaccharide. The preparation method of this invention is simple, has a high yield, and is suitable for large-scale production.
[0005] This invention employs chemical composition determination, high performance liquid chromatography, Fourier transform infrared spectroscopy, and methylation analysis to preliminarily characterize the structure of the extracted distillers' grains polysaccharide.
[0006] This invention also proposes the application of polysaccharides extracted from distiller's grains in alleviating ulcerative colitis, including alleviating ulcerative colitis-induced weight loss, downregulating the disease activity (DAI) index, reducing colonic shortening and pathological damage in ulcerative colitis mice, and inhibiting inflammatory responses.
[0007] To achieve the above objectives, the present invention provides the following technical solution:
[0008] This invention provides a wine lees polysaccharide VPS-30 for treating ulcerative colitis. The molecular weight of the wine lees polysaccharide VPS-30 is 111.97 kDa, and the monosaccharide composition of the wine lees polysaccharide VPS-30 is mannose, glucose, galactose, xylose, arabinose, and galacturonic acid.
[0009] Preferably, the molar percentages of mannose, glucose, galactose, xylose, arabinose, and galacturonic acid are 14.39–22.57: 64.9–76.04: 5.88–7.38: 1.89–2.79: 2.01–2.91: 1.93–2.87.
[0010] This invention also provides a method for preparing VPS-30, a polysaccharide derived from distiller's grains, comprising the following steps:
[0011] (1) Heat water to extract the raw materials of distiller's grains, then centrifuge and collect the supernatant;
[0012] (2) After mixing the supernatant obtained in step (1) with the ethanol solution, let it stand and centrifuge in sequence to collect the precipitate;
[0013] (3) After dissolving the precipitate obtained in step (2) in water, the solution is first treated with Sevage reagent to remove the protein, then the Sevage reagent is removed by rotary evaporation, and the crude wine lees polysaccharide VPS is obtained by freeze drying.
[0014] (4) Prepare crude wine lees polysaccharide VPS solution, and after ethanol fractionation and precipitation, the precipitate is wine lees polysaccharide VPS-30.
[0015] Preferably, in step (1), the volume ratio of distiller's grains to water is 1:8 to 12; the extraction temperature is 80 to 100°C, and the extraction time is 4 to 6 hours. The water-soluble polysaccharides in the distiller's grains are dissolved in water through hot water extraction, which is simple to operate and inexpensive.
[0016] Preferably, in step (2), the volume ratio of the supernatant to the ethanol solution is 1:3 to 5; the mass fraction of the ethanol solution is 90 to 98%. The addition of ethanol causes the polysaccharides in the aqueous solution to precipitate.
[0017] Preferably, the specific method for removing proteins from the solution using Sevage reagent in step (3) is as follows: The solution and Sevage reagent are mixed evenly in a separatory funnel at a volume ratio of 4-6:1. After standing and separating into layers, the lower organic phase is removed. This process is repeated until no white precipitate remains, resulting in a protein-free solution. Sevage reagent can denature and precipitate proteins in polysaccharide solutions, thus separating them. Sevage reagent has high protein removal efficiency and minimal polysaccharide loss.
[0018] Preferably, the volume concentration of the precipitate in the solution is 0.8-1.2%; and the volume ratio of chloroform to n-butanol in the Sevage reagent is 3-5:1.
[0019] Preferably, the specific method for ethanol fractionation precipitation in step (4) is as follows: the crude wine lees polysaccharide VPS solution is mixed evenly with ethanol to obtain system 1, which is then allowed to stand and centrifuged to obtain precipitate 1 and supernatant 1; the supernatant 1 is mixed evenly with ethanol to obtain system 2, which is then allowed to stand and centrifuged to obtain precipitate 2.
[0020] Fractional ethanol precipitation is a polysaccharide separation and purification technique based on differences in solubility. This method utilizes the significant differences in solubility of polysaccharides with different molecular weights and structural characteristics in an ethanol-water system. By gradually increasing the ethanol concentration, effective separation of polysaccharide components is achieved. As the ethanol concentration gradient increases, polysaccharide components with larger molecular weights and lower polarity preferentially precipitate, while components with smaller molecular weights and higher polarity precipitate at higher ethanol concentrations, thus achieving fine fractionation of polysaccharides. This method is characterized by its simplicity, low cost, and ease of scale-up, and is widely used in the separation and purification of polysaccharides.
[0021] Preferably, the content of crude distillers' grains polysaccharide VPS in the crude distillers' grains polysaccharide VPS solution is 8-12 mg / mL;
[0022] The final concentration of ethanol in system 1 is 15-25% (v / v); the final concentration of ethanol in system 2 is 25-35% (v / v).
[0023] The present invention also provides the application of the aforementioned wine lees polysaccharide VPS-30 in the preparation of anti-ulcerative colitis drugs.
[0024] It contains at least the following beneficial technical effects:
[0025] This invention employs a combination of hot water extraction and fractional alcohol precipitation to extract and purify polysaccharides from distiller's grains, resulting in a novel homogeneous polysaccharide from distiller's grains. The method is simple and convenient.
[0026] In mouse experiments, this invention found that VPS-30 can significantly improve colitis symptoms in mice with ulcerative colitis, improve colonic shortening and pathological damage in mice with ulcerative colitis, and improve intestinal flora imbalance in mice with ulcerative colitis.
[0027] The VPS-30 extracted using the method described in this invention exhibits high yield, strong drug stability, and high anti-inflammatory activity, indicating that VPS-30 has the potential to be developed into a functional food and pharmaceutical raw material for alleviating ulcerative colitis. Furthermore, it can be administered orally, increasing the route of administration; the process is simple, low-cost, and suitable for large-scale industrial production. Attached Figure Description
[0028] Figure 1 The relative molecular weight of VPS-30, a polysaccharide derived from distiller's grains, in Example 2;
[0029] Figure 2 The infrared spectrum of VPS-30 polysaccharide from distiller's grains in Example 4;
[0030] Figure 3 The effect of distillers' grains polysaccharide VPS-30 on body weight in mice with ulcerative colitis, as shown in Example 5;
[0031] Figure 4 The effect of distillers' grains polysaccharide VPS-30 on the DAI index in mice with ulcerative colitis, as shown in Example 5;
[0032] Figure 5 The effect of distillers' grains polysaccharide VPS-30 on colon length in mice with ulcerative colitis in Example 5; where A is the actual measurement graph and B is the bar chart.
[0033] Figure 6 HE staining of the colon of mice with ulcerative colitis treated with distillers' grains polysaccharide in Example 5, scale bar is 100 μm;
[0034] Figure 7 The effect of distillers' grains polysaccharide VPS-30 on the α-diversity of gut microbiota in mice with ulcerative colitis in Example 5; where A is the Shannon index and B is the Chao index;
[0035] Figure 8 This study describes the effect of VPS-30 (a polysaccharide from distiller's grains) on the relative abundance of intestinal flora in mice with ulcerative colitis, as described in Example 5. Detailed Implementation
[0036] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention. The invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely descriptive and do not limit the invention in any way. The raw materials and reagents used in the embodiments are commercially available conventional products; experimental methods not specifying specific conditions in the embodiments are generally performed under conventional conditions in the art; the distiller's grains raw material originates from Shanxi Xinghuacun Fenjiu Group Co., Ltd.
[0037] Example 1: Preparation method of wine lees polysaccharide (VPS-30)
[0038] Experimental methods: (1) Prepare the raw materials of distiller's grains and distilled water in a ratio of 1:10, first extract at 90℃ for 5h, then centrifuge at 7000rpm / min for 15min to collect the supernatant, repeat twice;
[0039] (2) Add 4 times the volume of 95% ethanol to the supernatant, let it stand at 4℃ for 12h, and collect the precipitate after centrifugation;
[0040] (3) The precipitate was dissolved in distilled water to prepare a 1% polysaccharide solution. It was then placed in a separatory funnel with Sevage reagent at a ratio of 5:1 (v / v), mixed evenly, allowed to stand and separate into layers, and the lower layer was removed. This process was repeated several times until no white precipitate was found. Sevage reagent was removed by rotary evaporation, and the crude wine lees polysaccharide VPS was obtained by vacuum drying at -20℃ for 10 hours using a freeze dryer.
[0041] (4) Prepare a 10 mg / mL aqueous solution of crude wine lees polysaccharide VPS, slowly add anhydrous ethanol to a final concentration of 20% (v / v), let stand at 4℃ for 12 h, centrifuge at 4000 rpm for 15 min, and collect the supernatant.
[0042] (5) Add anhydrous ethanol to the supernatant to a final concentration of 30% (v / v), let stand at 4℃ for 12h, centrifuge at 4000rpm for 15min, collect the precipitate, and freeze dry at -20℃ for 10h to obtain wine lees polysaccharide VPS-30.
[0043] (6) Calculate the yield and chemical composition of VPS-30.
[0044] Yield (%) = Mass of crude distillers' grains polysaccharide VPS-30 obtained (g) / Mass of crude distillers' grains polysaccharide VPS (g); Neutral sugar content (%) = Neutral sugar concentration (mg / mL) / Polysaccharide solution concentration (mg / mL); Uronic acid content (%) = Galacturonic acid concentration (mg / mL) / Polysaccharide solution concentration (mg / mL); Protein content (%) = Protein concentration (mg / mL) / Polysaccharide solution concentration (mg / mL). The results calculated using the above formulas are shown in Table 1.
[0045] Table 1. Yield and chemical composition of VPS-30
[0046]
[0047] Example 2: Relative molecular weight of VPS-30
[0048] Experimental methods: (1) Weigh 5 mg of VPS-30 sample prepared in Example 1, add 1 mL of 0.1 M Na2NO3 solution to the mobile phase, dissolve and filter with a 0.22 μm filter, sonicate to remove bubbles, and prepare sample solution; prepare standard solutions of dextran standards of different molecular weights according to the above method.
[0049] (2) The relative molecular weight of the samples was determined using a high-performance differential liquid chromatograph. The instrument was equipped with a differential refractive index detector, and the chromatographic column was a Waters Ultrahydrogel column (7.8 mm × 300 mm, 6 μm). The operating conditions were as follows: 0.1 M Na2NO3 solution as the mobile phase, flow rate of 0.5 mL / min, temperature of 40 °C, injection volume of 10 μL, and running time of 30 min.
[0050] (3) Load the above standard solutions sequentially, record the retention time T and spectrum of each standard, plot the standard curve and obtain the regression equation y = -0.5187x + 14.212, where the abscissa is T and the ordinate is logMw. Load the above sample solutions, record the retention time and spectrum, and calculate the relative molecular weight of sample VPS-30 based on the standard curve.
[0051] The results show that: (See Table 2 for details) Figure 1 As shown, the peak elution time was 17.67 min. Substituting this into the standard curve, the relative molecular weight of the distillers' grains polysaccharide (VPS-30) was calculated to be 111.97 kDa.
[0052] Table 2 Relative molecular weight of VPS-30
[0053]
[0054] Example 3: Monosaccharide composition of VPS-30 (fermentation lees polysaccharide)
[0055] Experimental method: (1) Weigh 5 mg of VPS-30 sample prepared in Example 1, add 5 mL of 4 mol / L trifluoroacetic acid solution, hydrolyze at 110℃ for 4 h, cool to room temperature, and repeatedly add 1 mL of methanol to dry under vacuum.
[0056] (2) Add 1 mL of distilled water to the above sample. Prepare a 5 mg / mL standard solution of monosaccharide standard with distilled water. Take 400 μL of sample solution and 400 μL of standard solution, and add 0.4 mL of 0.3 mol / L NaOH solution and 0.4 mL of 0.5 mol / L PMP-methanol solution respectively. Incubate in a water bath at 70 °C for 2 h. Cool to room temperature, add 0.4 mL of 0.3 mol / L HCl solution respectively, and then extract three times with 1 mL of chloroform. Retain the aqueous layer and filter through a 0.22 μm filter.
[0057] (3) The monosaccharide composition in VPS-30 was determined by high performance liquid chromatography (HPLC). The instrument was equipped with an ultraviolet detector and a Shim-pack GIST-C18 column (4.6 mm × 250 mm, 5 μm). The operating conditions were as follows: a mixture of KH2PO4 (A, 0.1 mol / L, pH = 6.85) solution and acetonitrile (B) was used as the mobile phase, the flow rate was 1 mL / min, the temperature was 40 °C, and the injection volume was 10 μL. Gradient elution was performed with the following elution gradients: 0 min - 22 min, B solution maintained at 18%; 22 min - 30 min, B solution linear gradient from 18% to 40%; 30 min - 39 min, B solution linear gradient maintained at 40%; 39 min - 40 min, B solution linear gradient from 40% to 18%.
[0058] The results are shown in Table 3: The monosaccharides of VPS-30 consist of mannose, glucose, galactose, xylose, arabinose and galacturonic acid, with a molar percentage of 18.48:70.47:6.63:2.34:2.46:2.40.
[0059] Table 3 Monosaccharide composition of VPS-30
[0060]
[0061] Example 4: Infrared spectrum of VPS-30 polysaccharide from distiller's grains
[0062] Experimental method: 10 mg of dried polysaccharide sample was thoroughly ground and mixed with 100 mg of potassium bromide powder, then pressed into thin sheets. The samples were then analyzed using an infrared spectrometer at 400-4000 cm⁻¹. -1 Scanning analysis within the range.
[0063] The results show that the wavenumber is 3246 cm⁻¹. -1The strong absorption peaks around the left and right are a result of the OH stretching vibration; wavenumber 2999 cm⁻¹ -1 The absorption peaks around the left and right are the stretching vibration peaks of the CH group of the glycosyl group, with a wavenumber of 2363 cm⁻¹. -1 The weak vibrational absorption peaks around the left and right are the result of intramolecular CH vibrations; wavenumber 1652 cm⁻¹ -1 The strong absorption peaks on the left and right are absorption peaks of the stretching vibration of C=O; wavenumber 1418 cm⁻¹ -1 The absorption peaks around the left and right are due to the stretching vibration of CH; the absorption peaks are in the range of 1250-950 cm⁻¹. -1 The information indicated the presence of a pyran ring conformation in the structure of VPS-30; wavenumber 862 cm⁻¹ -1 The presence of absorption peaks on both sides indicates the existence of α-glycosidic bonds and the presence of a pyran ring conformation in the structure (see...). Figure 2 ).
[0064] Example 5: Effects of VPS-30 on relevant indicators in mice with ulcerative colitis
[0065] Experimental methods: (1) Thirty male C57 / BL6J mice were randomly divided into three groups after 7 days of adaptive feeding: control group, model group (DSS), and VPS-30 group (DSS+VPS-30), with 10 mice in each group. Mice in the control group had free access to sterile water, while mice in the model group and FAPS-H group had free access to water containing 2.5% DSS. At the same time, mice in the control group and model group were given physiological saline (10 mL / kg) by gavage daily, and mice in the VPS-30 group were given VPS-30 suspension (200 mg / kg) by gavage for 14 days. After the experiment, mice were anesthetized with isoflurane, euthanized by cervical dislocation, and spleens were harvested, weighed, and colon tissue was removed, photographed and measured. The intestinal contents of the mice were then collected in a sterile operating table for intestinal flora detection. A portion of the mouse colon was fixed in 4% paraformaldehyde for HE staining.
[0066] (2) Histopathological analysis: The slide was ignited with a flame and placed in xylene, and this process was repeated to dewax the slide. The sample was then immersed in anhydrous ethanol, 95% ethanol, 90% ethanol, 80% ethanol, 70% ethanol and distilled water for 5 min each to remove xylene. The slide was stained with hematoxylin for 3 min and rinsed with tap water. The sample was then placed in 1% hydrochloric acid alcohol solution for differentiation, rinsed with tap water, treated with 0.6% ammonia water for blueing, and then rinsed with tap water. The sample was then placed in eosin staining solution for 1 min and rinsed with tap water. The sample was then immersed in distilled water, 70% ethanol, 80% ethanol, 90% ethanol, 95% ethanol and anhydrous ethanol for 5 min each, and finally immersed in xylene for 5 min. After dehydration, the slide was mounted with neutral resin. The sample was observed and images were acquired under a microscope.
[0067] (3) Detection of gut microbiota: Total DNA of the microbial community was extracted from feces using a kit from Omega Medical Materials Co., Ltd. (USA). The quality, concentration, and purity of the DNA were detected by agarose gel electrophoresis and a micro-nucleic acid protein analyzer, respectively. Then, the variable regions of 16S rRNA gene V3-V4 were amplified (forward primer 338F (SEQ ID NO.1): ACTCCTACGGGAGGCAG CAG; reverse primer 806R (SEQ ID NO.2): GGACTACHVGGGTWTCT AAT; W represents A+T; H represents A+C+T; V represents A+C+G). The amplification program consisted of four stages: pre-denaturation (95℃, 3 min), denaturation (95℃, 30 s), annealing (55℃, 30 s), extension (72℃, 30 s), and re-extension (72℃, 10 min). In the experiment, the denaturation, annealing, and extension stages were repeated 27 times. After amplification, the sample was stored at 4℃. The PCR reaction system consisted of 20 μL of 10 ng DNA template, 0.8 μL of 5 μmol forward primer, 0.8 μL of 5 μmol reverse primer, 2 μL of 2.5 mmol / L dNTPS, 4 μL of 5×TransStartFastPf buffer, 0.4 μL of TransStartFastPf DNA polymerase, and a trace amount of sterile ultrapure water. After mixing the PCR products from the same sample, the PCR products were recovered and purified using 2% agarose gel electrophoresis, and then quantitatively analyzed. Finally, after library construction, sequencing analysis was performed using the MisegPE300 platform.
[0068] The results show that: Figure 3 As shown, during DSS induction, compared with the normal group, the body weight of mice in both the model group and the VPS-30 group decreased to varying degrees, with the model group showing the most significant weight loss. VPS-30 significantly alleviated the weight loss induced by DSS. Figure 4 As shown, compared with the normal group mice, the DAI index of the model group increased with the increase of DSS treatment time. Compared with the model group, the DAI index of the VPS-30 group mice was lower, indicating that the severity of ulcerative colitis in the VPS-30 group mice was lower. Figure 5 As shown, compared with the model group, the colon length of mice in the VPS-30 group was restored; Figure 6As shown, the pathological features of the normal group mice were normal, while the pathological features of the model group mice were significantly changed, including crypt disappearance, a large reduction in goblet cells, extensive inflammatory cell infiltration, mucosal erosion, and submucosal edema. Compared with the model group, the above colitis symptoms were alleviated in the VPS-30 group, indicating that VPS-30 can inhibit colonic damage and inflammatory response induced by DSS; α-diversity can be used to evaluate the abundance and diversity of gut microbiota, of which the Chao index can reflect abundance and the Shannon index can reflect diversity. Figure 7 As shown, compared with the model group, the normal group had higher Chao and Shannon indices, indicating that the colitis mice had lower gut microbiota richness. Compared with the model group, the Chao and Shannon indices in the VPS-30 group increased, indicating that VPS-30 can increase the gut microbiota richness and diversity of colitis mice. Figure 8 As shown, at the phylum level, the gut microbiota in the normal group was mainly composed of Clostridia, Bacteroidotia, and Bacilli. Compared with the normal group, the relative abundance of Clostridia and Bacteroidotia in the gut microbiota of the model group was downregulated, while the relative abundance of Gammaproteobacteria was significantly upregulated. VPS-30 intervention brought the relative abundance of these microbiota closer to that of the normal group.
[0069] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A wine lees polysaccharide VPS-30 for treating ulcerative colitis, characterized in that, The molecular weight of the polysaccharide VPS-30 is 111.97 kDa, and the monosaccharide composition of the polysaccharide VPS-30 is mannose, glucose, galactose, xylose, arabinose and galacturonic acid.
2. The distillers' grains polysaccharide VPS-30 according to claim 1, characterized in that, The molar percentages of mannose, glucose, galactose, xylose, arabinose, and galacturonic acid are 14.39–22.57: 64.9–76.04: 5.88–7.38: 1.89–2.79: 2.01–2.91: 1.93–2.
87.
3. A method for preparing the distillers' grains polysaccharide VPS-30 according to claim 1 or 2, characterized in that, Includes the following steps: (1) Heat water to extract the raw materials of distiller's grains, then centrifuge and collect the supernatant; (2) After mixing the supernatant obtained in step (1) with the ethanol solution, let it stand and centrifuge in sequence to collect the precipitate; (3) After dissolving the precipitate obtained in step (2) in water, the solution is first treated with Sevage reagent to remove the protein, then the Sevage reagent is removed by rotary evaporation, and the crude wine lees polysaccharide VPS is obtained by freeze drying. (4) Prepare crude wine lees polysaccharide VPS solution, and after ethanol fractionation and precipitation, the precipitate is wine lees polysaccharide VPS-30.
4. The preparation method according to claim 3, characterized in that, In step (1), the volume ratio of the raw material of distiller's grains to water is 1:8 to 12; the extraction temperature is 80 to 100°C, and the extraction time is 4 to 6 hours.
5. The preparation method according to claim 3, characterized in that, In step (2), the volume ratio of the supernatant to the ethanol solution is 1:3 to 5; the mass fraction of the ethanol solution is 90 to 98%.
6. The preparation method according to claim 3, characterized in that, The specific method for removing protein with Sevage reagent in step (3) is as follows: mix the solution and Sevage reagent in a separatory funnel at a volume ratio of 4 to 6:1, let it stand to separate the layers, remove the lower organic phase, and repeat the above steps until there is no white precipitate to obtain a solution with protein removed.
7. The preparation method according to claim 6, characterized in that, The volume concentration of the precipitate in the solution is 0.8-1.2%; the volume ratio of chloroform to n-butanol in the Sevage reagent is 3-5:
1.
8. The preparation method according to claim 3, characterized in that, The specific method for ethanol fractionation precipitation in step (4) is as follows: mix crude wine lees polysaccharide VPS solution with ethanol to obtain system 1, let stand, centrifuge to obtain precipitate 1 and supernatant 1; mix supernatant 1 with ethanol to obtain system 2, let stand, centrifuge to obtain precipitate 2.
9. The preparation method according to claim 3, characterized in that, The content of crude distillers' grains polysaccharide VPS in the crude distillers' grains polysaccharide VPS solution is 8-12 mg / mL; The final concentration of ethanol in system 1 is 15-25% (v / v); the final concentration of ethanol in system 2 is 25-35% (v / v).
10. The use of VPS-30, a polysaccharide derived from distillers' grains according to claim 1 or 2, or VPS-30 prepared by any one of claims 3 to 9, in the preparation of an anti-ulcerative colitis drug.