American ginseng neutral polysaccharide XYS-W as well as preparation method and application thereof

Abstract

The invention provides American ginseng neutral polysaccharide XYS-W as well as a preparation method and application thereof, and belongs to the technical field of polysaccharide extraction. The weight-average molecular weight of the American ginseng neutral polysaccharide XYS-W disclosed by the invention is 28.66 kDa. A new neutral polysaccharide XYS-W is separated from American ginseng, the weight-average molecular weight of the American ginseng neutral polysaccharide XYS-W is 28.66 kDa, and the American ginseng neutral polysaccharide XYS-W is fructan with-> 1, 6)-Fruf-(2-> as a main connection mode. The American ginseng neutral polysaccharide XYS-W has good anti-pneumonia activity, low toxic and side effects and good application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of polysaccharide extraction, and particularly relates to a neutral polysaccharide XYS-W from American ginseng, a preparation method thereof, and an application thereof. Background Art

[0002] American ginseng Panax quinquefolium Panax quinquefolius L. is a perennial herb of the genus Panax in the Araliaceae family, and its root is used as medicine. American ginseng is bitter in taste and cool in nature, entering the heart, lung, and kidney meridians. Its main functions are tonifying, and it can nourish yin and reduce fire, replenish qi and promote fluid production. Clinically, it is commonly used to treat various diseases such as chronic cough due to lung deficiency, dry mouth and throat, less body fluid, and deficiency-fire restlessness and fatigue. American ginseng mainly contains saponin and polysaccharide components, and has the effects of strengthening the myocardium and central nervous system, regulating blood pressure, regulating endocrine, etc., and can enhance the function of the central nervous system, protect the cardiovascular system, improve immunity, and promote blood vitality.

[0003] In order to fully explore the polysaccharide medicinal substances of American ginseng, the inventors of the present invention studied the polysaccharide components of American ginseng, and isolated a new neutral polysaccharide, and the obtained polysaccharide component has strong anti-pneumonia activity. Summary of the Invention

[0004] The purpose of the present invention is to provide a neutral polysaccharide from American ginseng, a preparation method thereof, and an application thereof.

[0005] In order to achieve the above-mentioned invention purpose, the present invention provides the following technical solutions: The present invention provides a neutral polysaccharide XYS-W from American ginseng, and the structural formula of the neutral polysaccharide XYS-W from American ginseng is: ; The weight-average molecular weight of the neutral polysaccharide XYS-W from American ginseng is 28.66 kDa.

[0006] The present invention provides a preparation method of the neutral polysaccharide XYS-W from American ginseng, comprising the following steps: (1) Mix American ginseng medicinal materials with water and perform ultra-high pressure-assisted extraction to obtain an American ginseng water extract; (2) Mix the American ginseng water extract obtained in step (1) with an ethanol solution and react, and collect the solid part to obtain American ginseng crude polysaccharide; (3) Extract the American ginseng crude polysaccharide obtained in step (2) with petroleum ether and Sevage reagent in sequence to obtain an American ginseng polysaccharide extract; (4) Subject the American ginseng polysaccharide extract obtained in step (3) to ion exchange column chromatography, decompression concentration, and drying to obtain the neutral polysaccharide XYS-W from American ginseng; In step (1), the American ginseng medicinal material is crushed to 20 mesh, and the mass-volume ratio of the American ginseng medicinal material to water is 1 g: 40 mL; the pressure maintained during ultra-high pressure assisted extraction is 500 MPa, and the pressure maintaining time is 6 min; In step (2), the concentration of ethanol in the mixed solution obtained by mixing the American ginseng water extract and the ethanol solution is 60%, and the reaction time is 24 h; In step (3), the number of extractions with the petroleum ether and the Sevage reagent is 5 times each; the volume ratio of chloroform to n-butanol in the Sevage reagent is 4:1; In step (4), the ion exchange column is an anion exchange column, and the anion exchange column is a DEAE-52 ion exchange column; the eluent used during chromatography is ultrapure water; it is concentrated under reduced pressure to 1 / 40 of the original volume, and the drying is freeze-drying. The temperature of the freeze-drying is -25 °C, the vacuum degree is 30 Pa, and the time is 10 h.

[0007] The present invention provides an application of the above-mentioned American ginseng neutral polysaccharide XYS-W in the preparation of anti-inflammatory drugs.

[0008] Preferably, the anti-inflammatory drug is an anti-pneumonia drug.

[0009] The present invention provides an anti-inflammatory drug, and the drug contains the above-mentioned American ginseng neutral polysaccharide XYS-W.

[0010] Compared with the prior art, the present invention has the following beneficial effects: The present invention isolates a new neutral polysaccharide XYS-W from American ginseng. The weight-average molecular weight of the American ginseng neutral polysaccharide XYS-W is 28.66 kDa, and it is a fructan with →1,6)-Fruf-(2→ as the main linkage mode. The American ginseng neutral polysaccharide XYS-W has good anti-pneumonia activity and low toxicity and side effects, and has good application prospects. Description of the Drawings

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0012] Figure 1 It is the response surface diagram and contour diagram of the influence of the pressure maintaining time and pressure on the polysaccharide extraction rate in Example 1; Figure 2Response surface plot and contour plot of the effects of holding pressure time and solid-liquid ratio on the polysaccharide extraction rate in Example 1; Figure 3 Response surface plot and contour plot of the effects of holding pressure and solid-liquid ratio on the polysaccharide extraction rate in Example 1; Figure 4 Elution curve of polysaccharide in Example 2; Figure 5 Results of purity homogeneity analysis of XYS-W by gel permeation chromatography in Example 2; Figure 6 For the neutral polysaccharide XYS-W from American ginseng 1 1H NMR spectrum; Figure 7 For the neutral polysaccharide XYS-W from American ginseng 13 13C NMR spectrum; Figure 8 For the neutral polysaccharide XYS-W from American ginseng 1 H- 1 H COSY spectrum; Figure 9 HMQC spectrum of the neutral polysaccharide XYS-W from American ginseng; Figure 10 HMBC spectrum of the neutral polysaccharide XYS-W from American ginseng; Figure 11 Infrared spectrum of the neutral polysaccharide XYS-W from American ginseng; Figure 12 Structural formula of the neutral polysaccharide XYS-W from American ginseng; Figure 13 Results of the determination of the concentrations of key pro-inflammatory factors TNF-α and IL-6 in lung tissue homogenates and bronchoalveolar lavage fluids of mice in different groups in Example 4; where A is the concentration of TNF-α in lung tissue homogenates, B is the concentration of IL-6 in lung tissue homogenates, C is the concentration of TNF-α in bronchoalveolar lavage fluid (BALF), and D is the concentration of IL-6 in bronchoalveolar lavage fluid (BALF); a indicates P < 0.05 compared with the MOD group; b indicates P < 0.05 compared with the NS group. Detailed implementation manners

[0013] The technical solutions provided by the present invention will be described in detail below with reference to the examples, but they should not be construed as limiting the protection scope of the present invention.

[0014] Example 1 Study on the influence law of extraction process on the efficiency of American ginseng polysaccharide

[0015] 1 kg of American ginseng (purchased from Weihai Jinyiyang Pharmaceutical Co., Ltd.) was crushed to 20 meshes and extracted by ultrahigh pressure assisted extraction, with water as the solvent. Box-Behnken (response surface methodology) was used to optimize the ultrahigh pressure extraction parameters, and Design-Expert 12 software was used for analysis. A three-factor three-level response surface experimental scheme was established with polysaccharide yield as the response value and holding time (A), holding pressure (B), and solid-liquid ratio (C) as independent variables. The experimental results are shown in Table 1.

[0016] Table 1 Box-Behnken test results Design Expert 12 software was used to perform quadratic polynomial regression fitting on the experimental data, and the regression model was:

[0017] Through the P value test, the holding time (A), holding pressure (B) and solid-liquid ratio (C) have significant effects on the extraction rate of American ginseng polysaccharides (P < 0.05), while the effects of quadratic terms A², B² and C² are extremely significant (P < 0.0001), and the effects of other interaction terms are not significant. There is a nonlinear relationship between each factor and the polysaccharide yield, which further verifies the applicability of the response surface methodology. The F values ​​of each factor are F(A) = 73.50, F(B) = 352.67, and F(C) = 48.17, respectively, and their magnitude relationship is F(B) > F(C) >F(A), indicating that the influence of each factor on the extraction rate of American ginseng polysaccharides is as follows: holding pressure > solid-liquid ratio > holding time. High pressure conditions can effectively destroy the cell wall structure and promote the dissolution of polysaccharides; the appropriate solid-liquid ratio can optimize the utilization of the solvent, thereby increasing the polysaccharide yield; and the appropriate holding time is still the key factor to ensure the full dissolution of polysaccharides. The Box-Behnken response surface methodology was used to analyze variance and determine the significant effects of holding pressure, solid-liquid ratio and holding time on the extraction rate of American ginseng polysaccharides. The significance and goodness of fit of the model were also verified.

[0018] Table 2 ANOVA analysis

[0019] Note: R 2 =0.9952, R 2 adj=0.9864; ** indicates extremely significant (P<0.0001), * indicates significant (P<0.05) Figure 1Response surface plots and contour plots showing the effects of holding pressure time and pressure on the polysaccharide extraction rate, demonstrating the effects of holding pressure time (A) and holding pressure (B) on the yield of American ginseng polysaccharides. It can be seen from the figure that as the holding pressure time increases, the polysaccharide yield first increases significantly and then levels off; while as the holding pressure increases, the polysaccharide yield increases significantly. The contour plot is elliptical, indicating that there is a certain interaction between the holding pressure time and the holding pressure. Through response surface analysis, the polysaccharide yield reaches a maximum within the range of holding pressure time from 4.74 min to 7.43 min and holding pressure from 498.4 MPa to 543.53 MPa. This result shows that the effects of holding pressure time and holding pressure on the yield of American ginseng polysaccharides have a synergistic effect, and the maximum polysaccharide yield can be achieved within the above range.

[0020] Figure 2 Response surface plots and contour plots showing the effects of holding pressure time and solid-liquid ratio on the polysaccharide extraction rate, demonstrating the effects of holding pressure time (A) and solid-liquid ratio (C) on the yield of American ginseng polysaccharides. It can be seen from the figure that as the holding pressure time increases, the polysaccharide yield first increases significantly and then levels off; while as the solid-liquid ratio increases, the polysaccharide yield first increases and then decreases. The contour plot is elliptical, indicating that there is a certain interaction between the holding pressure time and the solid-liquid ratio. Through response surface analysis, the polysaccharide yield reaches a maximum within the range of holding pressure time from 4.74 min to 7.43 min and solid-liquid ratio from 1:36.63 to 1:40.62. This result shows that the effects of holding pressure time and solid-liquid ratio on the yield of American ginseng polysaccharides have a synergistic effect, and the maximum polysaccharide yield can be achieved within the above range.

[0021] Figure 3 Response surface plots and contour plots showing the effects of holding pressure and solid-liquid ratio on the polysaccharide extraction rate, demonstrating the effects of holding pressure (B) and solid-liquid ratio (C) on the yield of American ginseng polysaccharides. It can be seen from the figure that as the holding pressure increases, the polysaccharide yield first increases significantly and then levels off; while as the solid-liquid ratio increases, the polysaccharide yield first increases and then decreases. Its contour plot is elliptical and approximately circular, indicating that there is a certain interaction between the holding pressure and the solid-liquid ratio, but the interaction is not significant enough. Through response surface analysis, the polysaccharide yield reaches a maximum within the range of holding pressure from 498.4 MPa to 543.53 MPa and solid-liquid ratio from 1:36.63 to 1:40.62. This result shows that the effects of holding pressure and solid-liquid ratio on the yield of American ginseng polysaccharides have a certain synergistic effect, and the maximum polysaccharide yield can be achieved within the above range.

[0022] As can be seen from the above, the extraction effect is the best when the holding pressure is 500 MPa, the solid-liquid ratio is 1:40, and the holding pressure time is 6 min during ultra-high pressure assisted extraction.

[0023] In this example, through the optimization of the response surface method, the influence law of the extraction process on the extraction efficiency of American ginseng polysaccharides was deeply revealed. The research confirmed that the ultra-high pressure assisted extraction method not only significantly increased the polysaccharide yield, but also greatly shortened the extraction time and effectively reduced the energy consumption. The ultra-high pressure assisted extraction is carried out at room temperature, and this method avoids the destruction of the polysaccharide structure by high temperature and better maintains the biological activity of the polysaccharide.

[0024] Example 2 A method for preparing neutral polysaccharides from American ginseng is as follows: (1) Take 1 kg of American ginseng medicinal materials (purchased from Weihai Jinyiyang Pharmaceutical Co., Ltd.), pulverize them to 20 mesh, and then use the ultra-high pressure assisted extraction method for extraction. The ultra-high pressure assisted extraction uses water as the solvent, the pressure maintaining pressure during extraction is 500 MPa, the solid-liquid ratio is 1:40, and the pressure maintaining time is 6 min. Filter and concentrate the obtained extract to obtain the water extract of American ginseng.

[0025] (2) Mix the water extract obtained in step (1) with an ethanol-aqueous solution, adjust the ethanol content in the mixed solution to 60%, and let it stand for 24 h to completely precipitate the polysaccharides in the water extract. Filter by suction to obtain 180.28 g of crude American ginseng polysaccharides, and the extraction rate of the crude polysaccharides is 18.02%.

[0026] (3) Dissolve the crude American ginseng polysaccharides obtained in step (2) in 500 mL of water, place them in a separating funnel, and extract with petroleum ether 5 times (1000 mL×5) to remove the fat-soluble components in the water extract. Extraction process: After shaking the separating funnel 10 times, let it stand for 6 h, and separate the petroleum ether layer. Subsequently, use Sevage reagent (chloroform: n-butanol = 4:1, v / v) to extract the de-esterified polysaccharide aqueous solution 5 times (500 mL×5) to remove the proteins mixed in the polysaccharides. Extraction process: After shaking the separating funnel 10 times, let it stand for 6 h, and separate the Sevage reagent layer. Concentrate the protein-free polysaccharide aqueous solution under reduced pressure to remove the residual organic solvents to obtain a polysaccharide extract (it is calculated that 10 g of polysaccharide extract can be obtained from 55.5 g of American ginseng medicinal materials).

[0027] (4) Take 10 g of the polysaccharide extract obtained in step (3) and separate and purify it by DEAE-52 ion exchange column chromatography. Dissolve the polysaccharide extract in water, add it to the upper end of the DEAE-52 chromatographic column, and elute with ultrapure water with a volume of 2 L. Use 50 mL centrifuge tubes to collect the elution fractions, and collect 40 tubes. Detect the polysaccharide content of each tube by the sulfuric acid-phenol method, use an enzyme-linked immunosorbent assay instrument to detect the absorbance value at a wavelength of 490 nm, and draw an elution curve. The elution curve is as Figure 4As shown, there is only one main peak, indicating that only one polysaccharide component is contained. According to the elution curve, the eluates rich in polysaccharides (the eluates from tubes 13 to 16) were combined and concentrated under reduced pressure to 50 mL, and then freeze-dried for 10 h at a temperature of -25°C and a vacuum degree of 30 Pa to obtain a neutral polysaccharide from American ginseng (1.5 g), named American ginseng neutral polysaccharide XYS-W. Gel permeation chromatography was used to analyze the purity and homogeneity of XYS-W. Figure 5 As shown, it indicates that this polysaccharide is a polysaccharide component. 1.5 g of American ginseng neutral polysaccharide XYS-W can be extracted from 55.5 g of American ginseng medicinal materials, and the yield is 2.70%.

[0028] Example 3 1. Structural identification of American ginseng neutral polysaccharide XYS-W The American ginseng neutral polysaccharide XYS-W separated in Example 1 was measured by Nicolet IS50, HPGPC high-performance liquid gel chromatography and Burker AVIII HD 600 MHz nuclear magnetic resonance spectrometer for infrared spectrum (IR), molecular weight, and nuclear magnetic (NMR) spectrum, respectively, and its monosaccharide composition and linkage sites were analyzed. The results are shown in Table 3 and Figures 6 - 11 As shown, a new neutral polysaccharide structure was identified.

[0029] XYS-W is a light yellow amorphous powder. The molecular weight was determined to be 28.66 kDa by multi-angle laser light scattering method. The monosaccharide composition of XYS-W was determined by acid hydrolysis method to be composed of glucose (Glc) and fructose (Fru), and their molar ratio was 3.92:1. The results of methylation analysis showed that the main monosaccharide linkage types of XYS-W were Fruf-(2→, →1,6)-Fruf-(2→, →4,6)-Glcp-(1→, →4)-Glcp-(1→, Glcp-(1→, and their proportions were 0.12, 0.42, 0.06, 0.06, 0.34, respectively. Among them, the →1,6)-Fruf-(2→ glycosidic bond had the highest proportion. Thus, it can be preliminarily speculated that XYS-W is a fructan mainly connected by →1,6)-Fruf-(2→.

[0030] In the IR spectrum ( Figure 11 ), the absorption peaks at 3385 cm -1 and 2933 cm -1 are the stretching vibration peaks of O-H and C-H.

[0031] In the 13 13C NMR spectrum of XYS-W ( Figure 7Characteristic signals of fructan can be seen, and three prominent carbon signals appear in the low-field region, located at 103.66, 103.61, and 103.19 ppm, respectively. These signals do not show related hydrogen signals in the HSQC spectrum (heteronuclear single quantum coherence spectrum, Figures 8 - 10 ), indicating that this carbon signal is the C-2 carbon signal in fructose. According to relevant references and methylation results, δ C 103.63, 103.61, and 103.19 are named A, B, and C, respectively. Through 1 1H NMR ( Figure 6 ), 13 13C NMR ( Figure 7 ), 1 1H- 1 1H COSY spectrum ( Figure 8 ), HSQC ( Figure 9 ), and HMBC ( Figure 10 ), the H and C signals of the A, B, and C sugar residue fragments are further determined. In fragment A, the signals of C-1, C-3, C-4, C-5, and C-6 are located at 60.05 (3.83), 76.58 (4.19), 73.79 (4.05), 81.14 (3.91), and 62.56 (3.83), respectively, and it is inferred that fragment A is β-D-Fru f -(2→; in fragment B, the signals of C-1, C-3, C-4, C-5, and C-6 are 60.05 (3.83), 76.35 (4.29), 74.08 (4.05), 81.30 (3.90), and 62.33 (3.83), respectively, and it is inferred that fragment B is →1)-β-D-Fru f -(2→; in fragment C, the signals of C-1, C-3, C-4, C-5, and C-6 are 60.05 (3.83), 76.35 (4.29), 74.08 (4.05), 81.18 (3.89), and 62.15 (3.83), respectively, and it is inferred that fragment C is →1,6)-β-D-Fru f -(2→.

[0032] According to the signals of 1 1H, 13 13C NMR, and HSQC spectra, in addition to the fructose signals, XYS-W also detected three other anomeric signals at δ H / C 4.95 / 98.03, 4.67 / 95.85, and 5.413 / 92.12, and the three sugar residue fragments are numbered D, E, and F, respectively. The anomeric signal of fragment E indicates that it is in the β-configuration, while the anomeric signals of fragments D and E indicate that they are in the α-configuration. Through 1 1HNMR, 13 13C NMR, HSQC, HMBC,1 H- 1 The H and C signals of three sugar residue fragments were determined by the H- δ COSY spectrum. In fragment D, the signals appeared at 98.03 (4.97), 70.93 (3.54), 72.80 (3.77), 72.52 (3.49), 72.19 (3.92), 67.53 (3.81) respectively. It was inferred that fragment D was →4)-α-D-Glc p -(1→; In fragment E, the signals were 95.85 (4.67), 74.23 (3.27), 72.29 (3.62), 75.92 (3.53), 71.01 (3.76), 60.66 (3.69) respectively. It was inferred that fragment E was →4,6)- β-D-Glc p -(1→; In fragment F, the signals were 92.12 (5.42), 71.01 (3.57), 72.49(3.78), 69.16 (3.48), 72.34 (3.85), 61.26 (3.68) respectively. It was inferred that fragment F was t-α-D-Glcp-(1→.

[0033] Table 3 1 H NMR (600 MHz, D2O) and 13 C NMR data (150 MHz, D2O)

[0034] Example 4 The purpose of this example was to study the anti-pneumonia activity of neutral polysaccharide XYS-W from American ginseng.

[0035] 1. Establishment of a mouse acute pneumonia model An acute pneumonia mouse model was constructed by the method of intratracheal instillation of lipopolysaccharide (LPS) solution. The specific method was as follows: Grouping: Seventy-two male C57B / 6J mice were selected. After one week of adaptive feeding, they were randomly divided into 6 groups (12 mice in each group), namely: normal saline group (NS), model group (MOD), dexamethasone group (DEX, 5 mg / kg), XYS-W low-dose group (XYS-W-L, 50 mg / kg), XYS-W medium-dose group (XYS -W-M, 100 mg / kg), and XYS -W high-dose group (XYS -W-H, 200mg / kg).

[0036] Model establishment and drug administration: The volumes of the model establishment solution and drug administration solution for all groups were calculated as 0.1 mL / 10 g (volume / body weight) and administered accordingly. Except for the dexamethasone group which was administered by injection, the remaining groups were administered by gavage. The body weights of the mice were recorded daily during the experiment. After 7 days of pre-drug administration, once a day, the low, medium, and high-dose groups were gavaged with the corresponding doses of the drug according to the body weights of the mice, and the normal saline group and the model group were gavaged with an equal volume of normal saline.

[0037] One hour after the last drug administration, except for the normal saline group, the mice in the other groups were anesthetized by intraperitoneal injection of sodium pentobarbital solution, fixed in the supine position on the operating board, with the head slightly tilted backward, the oral cavity was gently opened with forceps and the glottis was exposed with the help of a light source; subsequently, the prepared LPS solution (50 μL, containing 5 mg / kg LPS) was slowly dropped into the trachea using a micropipette. After the infusion, the mice were kept upright for a moment to ensure that the solution fully entered the lungs, and finally the mice were put back into the cage to observe their respiratory recovery until they fully woke up.

[0038] 2. Determination of inflammatory factors The contents of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in the lung tissues and lung lavage fluids of the mice were detected by ELISA. Take 20 mg of lung tissue, add homogenization medium (180 μL of PBS solution) at a ratio of 1:9 (w / v), homogenize at low temperature, centrifuge at 4°C and 10,000 rpm for 15 minutes, collect the supernatant, and store it at -80°C for later use. The experiment was detected using kits (Sinobest Biological Mouse IL-6 ELISA kit (EMC004.96) and Sinobest Biological Mouse TNF-α ELISA kit (EMC102a.96)), and the operation was carried out strictly according to the instructions. The absorbance (OD value) of the standard products and samples was measured at a wavelength of 450 nm. The standard curve was fitted by ELISA Calc software to obtain the regression equation, and the concentrations of IL-6 and TNF-α in the lung tissues and lavage fluids were calculated.

[0039] The measurement results are as Figure 13 shown. It can be seen that compared with the NS group, LPS caused a significant increase in the levels of TNF-α and IL-6 in the lung tissue homogenate and bronchoalveolar lavage fluid (BALF) of the MOD group, while the DEX group significantly reduced the levels of both, and the XYS-W administration group showed a dose-dependent inhibitory effect, indicating that XYS-W has good anti-inflammatory activity and the anti-inflammatory ability gradually increases with the increase in dose.

[0040] The above is only the preferred embodiment of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and modifications can be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A neutral polysaccharide XYS-W from American ginseng, characterized in that, The structural formula of the neutral polysaccharide XYS-W from American ginseng is as follows: ； The weight-average molecular weight of the neutral polysaccharide XYS-W from American ginseng is 28.66 kDa.

2. The preparation method of American ginseng neutral polysaccharide XYS-W according to claim 1, characterized in that, It includes the following steps: (1) Mix the American ginseng medicinal materials with water and then perform ultra-high pressure-assisted extraction to obtain the water extract of American ginseng; (2) Mix the water extract of American ginseng obtained in step (1) with an ethanol solution and react, collect the solid part to obtain the crude polysaccharide of American ginseng; (3) Extract the crude polysaccharide of American ginseng obtained in step (2) successively with petroleum ether and Sevage reagent to obtain the polysaccharide extract of American ginseng; (4) Subject the polysaccharide extract of American ginseng obtained in step (3) to ion exchange column chromatography, decompress and concentrate, and dry to obtain the neutral polysaccharide XYS-W from American ginseng; In step (1), the American ginseng medicinal materials are crushed to 20 mesh, and the mass-volume ratio of the American ginseng medicinal materials to water is 1 g:40 mL; the pressure holding pressure during the ultra-high pressure-assisted extraction is 500 MPa, and the pressure holding time is 6 min; In step (2), the concentration of ethanol in the mixed solution obtained by mixing the water extract of American ginseng with the ethanol solution is 60%, and the reaction time is 24 h; In step (3), the number of extractions with the petroleum ether and the Sevage reagent is 5 times each; the volume ratio of chloroform to n-butanol in the Sevage reagent is 4:1; In step (4), the ion exchange column is an anion exchange column, and the anion exchange column is a DEAE-52 ion exchange column; the eluent used during the chromatography is ultrapure water; it is decompressed and concentrated to 1 / 40 of the original volume, and the drying is freeze-drying. The temperature of the freeze-drying is -25°C, the vacuum degree is 30 Pa, and the time is 10 h.

3. Use of the neutral polysaccharide XYS-W from American ginseng according to claim 1 in the preparation of anti-inflammatory drugs.

4. The application according to claim 3, characterized in that The anti-inflammatory drug is an anti-pneumonia drug.

5. An anti-inflammatory drug, characterized in that, The drug contains the neutral polysaccharide XYS-W from American ginseng according to claim 1.

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