Jute homogeneous polysaccharide with immune activation effect as well as preparation method and application of jute homogeneous polysaccharide

Abstract

The invention discloses jute homogeneous polysaccharide with an immune activation effect as well as a preparation method and application thereof, and belongs to the technical field of medicines. The invention aims to solve the technical problems of improving immune organ atrophy, caused by cyclophosphamide, of an immunosuppression model mouse, recovering morphological characteristics and blood cell quantity of the spleen and promoting generation of immune and inflammatory cytokines, so that the immune function of the mouse is recovered, and the effect of immune activation is achieved. The technical scheme is characterized in that the jute homogeneous polysaccharide is formed by connecting 3-4 parts by mole of rhamnose, 0.5-2 parts by mole of arabinose, 1-3 parts by mole of galactose and 1-2 parts by mole of galacturonic acid through glucosidic bonds.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medicine, in particular to a uniform polysaccharide of jute with immune activation efficacy, and a preparation method and application thereof. BACKGROUND

[0002] Jute (Corchorus capsularis L.) belongs to Malvaceae and is divided into jute for spinning and jute for eating. The leaves of jute for eating contain rich crude protein, dietary fiber, vitamins, amino acids, minerals and trace elements such as selenium. At present, the chemical components isolated or identified from the leaves of jute mainly include triterpenes, steroids, polysaccharides, polyphenols, organic acids and alkaloids, which have the effects of invigorating the spleen and stomach, moistening the intestines and relieving constipation, reducing blood pressure and the like. Natural polysaccharides have been confirmed to regulate immune responses by directly acting on immune cells, improving the microbiota and promoting the production of short-chain fatty acids. Among them, polysaccharides as one of the main active ingredients of jute leaves show obvious biological activities in antioxidant, anti-inflammatory, immune regulation and anti-tumor and the like, and have the potential to develop into immune modulators. However, the extraction rate of jute polysaccharides is low, and the separation and purification are difficult, and at present the preparation of uniform jute polysaccharides has not been realized, so that crude polysaccharides are used in pharmacological studies; the structure research of jute polysaccharides focuses on monosaccharide composition, and the position of side chain, high-order structure and structure-activity relationship are not reported in the literature, and the high-order structure of polysaccharides has a major impact on pharmacological activity. Therefore, the chemical structure of jute polysaccharides needs to be further clarified to explore the structure-activity relationship. In summary, since jute is widely available, the research on the purification, structure characterization and immune regulation of jute polysaccharides can provide new strategies for the treatment of immune system related diseases and provide theoretical basis for the high value utilization of jute resources.

[0003] The country of disclosure is China, the disclosure number is CN104812244A, and the disclosure date is 2015.07.29. The document discloses a method of enhancing specific immunotherapy in cancer treatment. Other aspects of the invention relate to compositions for parenteral administration, wherein the compositions are in an acceptable pharmaceutical carrier and include: (a) a therapeutically effective amount of a galacto-arabinosyl-rhamnose-galacturonate, which includes a 1,4-linked galacturonic acid (GalA) residue and a galacturonate methyl ester (MeGalA) residue backbone, the backbone is connected with a branched heteropolymer of an alpha-1,2 linked rhamnose residue and an alpha-1,4-linked GalA residue, the rhamnose residue carries a main branch of an oligomer of 1,4-beta-D-galactose residues, 1,5-alpha-L-arabinose residues or a combination thereof; and (b) a therapeutically effective amount of an immunomodulator. In some embodiments, the composition can be used for treating cancer.

[0004] CN105536713A, published on June 29, 2018, discloses extraction of jute polysaccharide and its application in removing hexavalent chromium ions. The invention uses leaves and young shoots of Corchorus olitorius L. as raw materials, and separates the abundant pectin and other polysaccharide substances in them by physical and chemical means. The jute polysaccharide prepared is identified by high performance liquid chromatography, and the purity is 81-94%. The obtained substance has good adsorption effect, and can increase the added value of jute, a traditional fiber crop.

[0005] Journal title: Natural Products Chemistry, document title: Induction of Apoptosis by Ethanolic Extract of Corchorus olitorius Leaf in Human Hepatocellular Carcinoma (HepG2) Cells via a Mitochondria-Dependent Pathway, volume 17, published in August 2012, discloses: Previous studies suggested that the cytotoxicity of phytol on cancer cells was due to an induction of apoptosis. Monogalactosyldiacylglycerol was shown to inhibit the activities of mammalian DNA polymerases including repair-related DNA polymerase β and induce severe apoptosis in gastric cancer cells with IC50 values less than 50 μg / mL. Thence, apoptosis in ECO-treated HepG2 cells through caspase-dependent mitochondrial pathway may be induced partially by phytol and monogalactosyl-diacylglycerol. (Previous studies suggested that the cytotoxicity of phytol on cancer cells was due to an induction of apoptosis. Monogalactosyldiacylglycerol was shown to inhibit the activities of mammalian DNA polymerases including repair-related DNA polymerase β and induce severe apoptosis in gastric cancer cells with IC50 values less than 50 μg / mL. Thence, apoptosis in ECO-treated HepG2 cells through caspase-dependent mitochondrial pathway may be induced partially by phytol and monogalactosyl-diacylglycerol.) The prior art represented by the aforementioned document has at least the following unsolved technical problems or drawbacks: (1) The extraction equipment of jute polysaccharide has high cost, complex operation and high energy consumption. The relevant evidence is: the document with publication number CN105536713A discloses the extraction of jute polysaccharide and its application in removing hexavalent chromium ions. Among them, the core step of the process "supercritical enzymolysis" needs to use special equipment such as high-pressure reaction kettle, CO2 pump and pressure control system. These equipment needs to withstand 10.0 MPa high pressure, and the manufacturing material (such as corrosion-resistant alloy) and sealing technology requirement is high, the purchase cost is much higher than that of traditional equipment; (2) The solubility and drug administration adaptability of the jute polysaccharide containing immune activation type medicament are limited. The relevant evidence is: the document with publication number CN104812244A discloses a method for enhancing specific immunotherapy in cancer treatment. Although the presence of galacturonate methyl ester (MeGal A) can improve water solubility by reducing hydrogen bonding between carboxyl groups, if the length and density of branched chains are out of control (such as too long arabinose / galactose branched chains), it may cause the increase of intermolecular hydrophobic interaction, leading to aggregation and precipitation, especially in high concentration preparations (such as concentrated solution for parenteral administration), which may affect the safety and absorption efficiency of drug administration.

[0006] In solving the above problems or overcoming the above defects, the present application has encountered the following difficulties and obstacles: (1) When using traditional water extraction, dilute acid / alkali extraction method, if the extraction time is prolonged or the temperature is increased to improve the yield, it may cause the structural damage of heat-sensitive polysaccharide such as glycosidic bond rupture, deacetylation, etc., and lose activity. Although ultrasonic / microwave assisted extraction can improve the dissolution efficiency through cavitation effect, local high temperature may cause the rupture of hydrogen bond within polysaccharide molecules and the decrease of polymerization degree, especially for polysaccharides containing sulfuric acid group, phosphoric acid group and other easily hydrolyzed groups.

[0007] (2) The biological activity of polysaccharide is closely related to the type of glycosidic bond, monosaccharide composition and branched structure, but the structure-activity relationship is difficult to be determined. SUMMARY

[0008] The purpose of the present application is to provide: A jute uniform polysaccharide with immune activation effect, and related technologies to solve the technical problems or combinations of immune organ atrophy of immunosuppressed model mice caused by cyclophosphamide, restore the morphological characteristics and blood cell number of spleen, promote the production of immune and inflammatory cytokines, thereby restoring the immune function of mice, achieving the effect of immune activation, improving the purity of jute uniform polysaccharide, etc.

[0009] In the first aspect, the present application provides: a jute uniform polysaccharide with immune activation effect, which is connected by 3-4 parts of rhamnose, 0.5-2 parts of arabinose, 1-3 parts of galactose and 1-2 parts of galacturonic acid by glycosidic bond, in terms of mole fraction.

[0010] The technical features include: rhamnose, arabinose, galactose, galacturonic acid, and molar ratio between each component.

[0011] The rhamnose is selected from at least one of: α-L-rhamnose furanose, β-L-rhamnose furanose, α-D-rhamnose furanose, β-D-rhamnose furanose, α-L-rhamnose pyranose, β-L-rhamnose pyranose, α-D-rhamnose pyranose, and β-D-rhamnose pyranose; preferably at least one of: α-L-rhamnose pyranose, β-L-rhamnose pyranose, α-D-rhamnose pyranose, and β-D-rhamnose pyranose; further preferably at least one of: α-L-rhamnose pyranose and β-L-rhamnose pyranose; and more preferably α-L-rhamnose pyranose.

[0012] The arabinose is selected from at least one of: α-L-arabinose furanose, β-L-arabinose furanose, α-D-arabinose furanose, β-D-arabinose furanose, α-L-arabinose pyranose, β-L-arabinose pyranose, α-D-arabinose pyranose, and β-D-arabinose pyranose; preferably at least one of: α-L-arabinose furanose, β-L-arabinose furanose, α-D-arabinose furanose, and β-D-arabinose furanose; further preferably at least one of: α-L-arabinose furanose and β-L-arabinose furanose; and more preferably α-L-arabinose furanose.

[0013] The galactose is selected from at least one of: α-L-galactose furanose, β-L-galactose furanose, α-D-galactose furanose, β-D-galactose furanose, α-L-galactose pyranose, β-L-galactose pyranose, α-D-galactose pyranose, and β-D-galactose pyranose; preferably at least one of: α-L-galactose pyranose, β-L-galactose pyranose, α-D-galactose pyranose, and β-D-galactose pyranose; further preferably at least one of: β-L-galactose pyranose and β-D-galactose pyranose; and more preferably β-D-galactose pyranose.

[0014] The galacturonic acid is selected from at least one of: a-L-galacturonic acid furanose, b-L-galacturonic acid furanose, a-D-galacturonic acid furanose, b-D-galacturonic acid furanose, a-L-galacturonic acid pyranose, b-L-galacturonic acid pyranose, a-D-galacturonic acid pyranose, b-D-galacturonic acid pyranose; preferably at least one of: a-L-galacturonic acid pyranose, b-L-galacturonic acid pyranose, a-D-galacturonic acid pyranose, b-D-galacturonic acid pyranose; further preferably at least one of: a-D-galacturonic acid pyranose, b-D-galacturonic acid pyranose; and more further preferably a-D-galacturonic acid pyranose.

[0015] The molar fraction of the components is further preferably 3.5 parts of a-L-rhamnose, 1 part of a-L-arabinose, 1.9 parts of b-D-galactose, and 1.4 parts of a-D-galacturonic acid.

[0016] Further, the structural formula of the uniform polysaccharide of the jute is as follows:

[0017] Formula I The number of repeating units m in the structural formula is selected from 2-6; and preferably 3.

[0018] The number of repeating units n in the structural formula is selected from 2-6; and preferably 3.

[0019] Based on further solving or simultaneously solving multiple technical problems of the technical problem of the present application, in the technical solution provided in the first aspect of the present application, the preferred scheme includes: The first preferred scheme: the rhamnose is selected from at least one of: a-L-rhamnose furanose, b-L-rhamnose furanose, a-D-rhamnose furanose, b-D-rhamnose furanose, a-L-rhamnose pyranose, b-L-rhamnose pyranose, a-D-rhamnose pyranose, b-D-rhamnose pyranose; preferably at least one of: a-L-rhamnose pyranose, b-L-rhamnose pyranose, a-D-rhamnose pyranose, b-D-rhamnose pyranose; further preferably at least one of: a-L-rhamnose pyranose, b-L-rhamnose pyranose; and more further preferably a-L-rhamnose pyranose. This technical solution further solves the technical problem of "further improving the immune activation effect" on the basis of solving the technical problem of "improving the immune activation effect".

[0020] The second priority scheme: the arabinose is selected from at least one of the following: alpha-L-arabinofuranose, beta-L-arabinofuranose, alpha-D-arabinofuranose, beta-D-arabinofuranose, alpha-L-arabinopyranose, beta-L-arabinopyranose, alpha-D-arabinopyranose, beta-D-arabinopyranose; preferably at least one of the following: alpha-L-arabinofuranose, beta-L-arabinofuranose, alpha-D-arabinofuranose, beta-D-arabinofuranose; further preferably at least one of the following: alpha-L-arabinofuranose, beta-L-arabinofuranose; more preferably alpha-L-arabinofuranose. The technical scheme solves the technical problem of "improving the immune activation effect" and further solves the technical problem of "further improving the immune activation effect".

[0021] The third priority scheme: wherein the galactose is selected from at least one of the following: alpha-L-galactofuranose, beta-L-galactofuranose, alpha-D-galactofuranose, beta-D-galactofuranose, alpha-L-galactopyranose, beta-L-galactopyranose, alpha-D-galactopyranose, beta-D-galactopyranose; preferably at least one of the following: alpha-L-galactopyranose, beta-L-galactopyranose, alpha-D-galactopyranose, beta-D-galactopyranose; further preferably at least one of the following: beta-L-galactopyranose, beta-D-galactopyranose; more preferably beta-D-galactopyranose. The technical scheme solves the technical problem of "improving the immune activation effect" and further solves the technical problem of "further improving the immune activation effect".

[0022] The fourth priority scheme: wherein the galacturonic acid is selected from at least one of the following: alpha-L-galacturonic acid furanose, beta-L-galacturonic acid furanose, alpha-D-galacturonic acid furanose, beta-D-galacturonic acid furanose, alpha-L-galacturonic acid pyranose, beta-L-galacturonic acid pyranose, alpha-D-galacturonic acid pyranose, beta-D-galacturonic acid pyranose; preferably at least one of the following: alpha-L-galacturonic acid pyranose, beta-L-galacturonic acid pyranose, alpha-D-galacturonic acid pyranose, beta-D-galacturonic acid pyranose; further preferably at least one of the following: alpha-D-galacturonic acid pyranose, beta-D-galacturonic acid pyranose; more preferably alpha-D-galacturonic acid pyranose. The technical scheme solves the technical problem of "improving the immune activation effect" and further solves the technical problem of "further improving the immune activation effect".

[0023] The fifth preferred solution: the molar fraction between components is further preferably 3.5 parts of α-L-rhamnose, 1 part of α-L-arabinose, 1.9 parts of β-D-galactose, and 1.4 parts of α-D-galacturonic acid. This technical solution further solves the technical problem of "further improving the immune activation effect" on the basis of solving the technical problem of "improving the immune activation effect".

[0024] The sixth preferred solution: wherein the repeating number of structural units m, n is selected from: 3, 3. This technical solution further solves the technical problem of "further improving the immune activation effect" on the basis of solving the technical problem of "improving the immune activation effect".

[0025] In the second aspect, the present application provides: a preparation method of the above-mentioned uniform corchorus olitorius polysaccharide, comprising the steps of: purifying the corchorus olitorius crude polysaccharide by ion exchange and gel filtration chromatography to obtain the uniform corchorus olitorius polysaccharide.

[0026] Among them, the technical features include: ion exchange purification, gel filtration chromatography purification.

[0027] Among them, the ion exchange purification comprises the steps of: dissolving the corchorus olitorius crude polysaccharide in a solvent to obtain a corchorus olitorius crude polysaccharide mother liquor; passing through an ion exchange column, collecting the eluent, and purifying to obtain the product corchorus olitorius polysaccharide component; Preferably, the solvent is selected from at least one of water, Tris-HCl buffer, phosphate buffer (PBS), and sodium chloride solution; further preferably, at least one of water and sodium chloride solution; still further preferably, the solvent is water.

[0028] Preferably, the concentration of the corchorus olitorius crude polysaccharide mother liquor is 10-30 mg / mL, and further preferably 20 mg / mL.

[0029] Preferably, before passing through the ion exchange column, the step of removing impurities from the corchorus olitorius crude polysaccharide mother liquor is further included.

[0030] The impurity removal includes but is not limited to common solid-liquid separation methods such as filtration and centrifugation.

[0031] Further preferably, the impurity removal is: centrifugation, and taking the supernatant.

[0032] Still further preferably, the centrifugation conditions are: centrifugation at a speed of 5000-20000 r / min for 5-30 min; most preferably: centrifugation at a speed of 10000 r / min for 10 min.

[0033] Preferably, the ion exchange column is selected from any one of a cellulose DEAE-cellulose column, an aminoethyl cellulose column, a Q Sepharose gel column, and a SP Sepharose gel column. Further preferably, the ion exchange column is selected from any one of Cellulose DEAE-52, Cellulose DEAE-22, Cellulose DEAE-23, Cellulose DEAE-32, and Cellulose DEAE-11. Still further preferably, the ion exchange column is Cellulose DEAE-52.

[0034] Preferably, the flow rate of the ion exchange column is 2-6 mL / min, and further preferably 4 mL / min.

[0035] Preferably, the elution conditions are: gradient elution with pure water, 0.05-0.15 M, 0.15-0.25 M, and 0.25-0.35 M NaCl solution, in sequence.

[0036] Further preferably, the elution conditions are: gradient elution with pure water, 0.1 M, 0.2 M, and 0.3 M NaCl solution, in sequence. Still further preferably, the elution conditions are: elution with 0.1 M NaCl solution. Preferably, the collected eluate refers to the eluate of 0.1 M NaCl solution, denoted as D2.

[0037] Preferably, the purification process comprises concentration and dialysis.

[0038] Further preferably, the concentration is to 1 / 4-1 / 6 of the original volume, and further preferably 1 / 5.

[0039] Further preferably, the dialysis is dialysis for 30-60 h with a dialysis bag having a molecular weight cut-off of 3000 Da, and further preferably dialysis for 48 h with a dialysis bag having a molecular weight cut-off of 3000 Da.

[0040] Further preferably, the purification process further comprises drying.

[0041] The drying method includes but is not limited to freeze-drying, oven drying, air drying, blow drying, natural drying, vacuum drying, etc.; further preferably, the drying method is freeze-drying; further preferably, the product of ion exchange purification is denoted as CCP-D2.

[0042] Preferably, the ion exchange purification comprises the steps of: (1) dissolving the impurity-removed jute crude polysaccharide sample in pure water to prepare a jute crude polysaccharide mother liquor; (2) centrifuging the jute crude polysaccharide mother liquor, taking the supernatant, and purifying it through an ion exchange column, eluting with 0.1 M NaCl solution, collecting one tube every 15 mL, and collecting all the eluate, denoted as D2; (3) taking the number of eluent tubes as the horizontal coordinate, and taking the total sugar content and the NaCl concentration in the eluent as the vertical coordinate, respectively, to draw the ion purification elution curve of the sample; (4) combining the eluents of each collection tube corresponding to the same elution peak; (5) concentrating the collected eluents; (6) dialyzing the collected eluents with a dialysis bag with a molecular weight cutoff of 3000 Da, and freeze-drying the dialyzed solution to obtain CCP-D2.

[0043] The gel filtration chromatography purification includes the following steps: The purified product obtained after ion purification is denoted as CCP-D2, and a solvent is added to prepare a CCP-D2 mother liquor, which is separated and purified by passing through a gel chromatography column, the eluent is collected, and the purified product is obtained.

[0044] Preferably, the solvent is at least one selected from water, a phosphate buffer, a NaCl solution, and a Tris-HCl buffer; further preferably, the solvent is water or a NaCl solution; and more preferably, the solvent is water.

[0045] Preferably, the concentration of the jute polysaccharide component mother liquor is 1-10 mg / mL, and further preferably, the concentration is 2 mg / mL.

[0046] Preferably, before passing through the gel chromatography column, the step of removing impurities from the jute crude polysaccharide mother liquor is further included.

[0047] The impurity removal includes, but is not limited to, common solid-liquid separation methods such as filtration and centrifugation.

[0048] Further preferably, the impurity removal is centrifugation, and the supernatant is taken.

[0049] More preferably, the centrifugation is performed at a speed of 5000-20000 r / min for 5-30 min. Most preferably, the centrifugation is performed at a speed of 10000 r / min for 10 min.

[0050] Preferably, the type of the gel chromatography column is at least one selected from the group consisting of cross-linked dextran gel Sephadex series, agarose gel Sepharose / Superose series, polyacrylamide gel Bio-Gel P series, and composite gel; further preferably, the type of the gel chromatography column is at least one selected from the group consisting of Sephadex G-75, Sephadex G-100, Superose 12, and Superdex 200 10 / 300 GL; and more preferably, the type of the gel chromatography column is Superdex 200 10 / 300 GL.

[0051] Preferably, the flow rate of the size-exclusion chromatography column is 0.5-2 mL / min, further preferably 1 mL / min.

[0052] Preferably, the elution conditions are: gradient elution with pure water, 0.05-0.15 M, 0.15-0.25 M and 0.25-0.35 M NaCl solution in sequence; further preferably: gradient elution with pure water, 0.1 M, 0.2 M and 0.3 M NaCl solution in sequence; and more preferably: elution with pure water.

[0053] Preferably, the elution volume is 1.0-2.0 times the column volume, further preferably 1.5 times the column volume.

[0054] Preferably, the purification process comprises concentration and drying.

[0055] Further preferably, the concentration is to 1 / 4-1 / 6 of the original volume, more preferably 1 / 5 of the original volume.

[0056] Further preferably, the drying method comprises, but is not limited to, freeze-drying, oven drying, air drying, blow drying, natural drying, vacuum drying, etc.; more preferably, the drying method is freeze-drying.

[0057] Preferably, the gel filtration chromatography purification comprises the following steps: (1) Take the ion-purified jute polysaccharide component CCP-D2, add pure water to prepare a 2 mg / mL jute polysaccharide component CCP-D2 stock solution; (2) Centrifuge the jute polysaccharide component CCP-D2 stock solution at 10,000 r / min for 10 min, take the supernatant, pass it through a size-exclusion chromatography column Superdex200 10 / 300 GL for separation and purification, the flow rate is 1 mL / min, elute with pure water at 1.5 times the column volume, and collect all the eluate; (3) Obtain a gel elution peak component, denoted as CCP-D2N1; (4) Combine the eluate of each collection tube corresponding to the elution peak, and concentrate to 1 / 5 of the original volume; (5) Freeze-dry, and identify the polysaccharide content and purity after gel purification by the sulfuric acid-phenol method, to obtain the uniform jute polysaccharide CCP-D2N1.

[0058] The preparation method of the jute crude polysaccharide comprises the following steps: (1) Extract jute leaves with a solvent by refluxing, and perform alcohol precipitation treatment on the extract to obtain a jute crude product; (2) Enzymatically hydrolyze the jute crude product obtained in step (1), extract and purify to obtain the jute crude polysaccharide.

[0059] Preferably, in step (1), the solvent comprises at least one of water, 0.1-1 M HCl solution, 0.1-1 M NaOH solution, and NaCl solution; further preferably, at least one of water, 0.1-1 M HCl solution, and 0.1-1 M NaOH solution; more preferably, water; most preferably, the temperature of the water is 60-100℃.

[0060] Preferably, in step (1), the ratio of jute leaves to solvent is 1:5-1:30.

[0061] For example, the ratio of jute leaves to water is 1:5-1:20, 1:10-1:20, or 1:10-1:30.

[0062] More preferably, the ratio of jute leaves to water is 1:8.

[0063] Preferably, in step (1), the number of reflux extraction is 1-3; further preferably, the number of reflux extraction is 2.

[0064] Preferably, in step (1), the reflux extraction time is 1-3 h; further preferably, the reflux extraction time is 2 h.

[0065] Preferably, in step (1), the alcohol content of the alcohol precipitation treatment solution is 80%-90%; further preferably, the alcohol content of the alcohol precipitation treatment solution is 80%.

[0066] Preferably, in step (2), before enzymolysis, the jute crude product is dissolved in a solvent.

[0067] Further preferably, the solvent is water or a NaCl solution; more preferably, the solvent is water.

[0068] Further preferably, the ratio of jute crude product to water is 1:50-1:120; more preferably, the ratio of jute crude polysaccharide to water is 1:100.

[0069] Further preferably, the dissolution method includes, but is not limited to, grinding pretreatment, ultrasonic-assisted dissolution, stirring intensity adjustment, etc. More preferably, the dissolution method is ultrasonic-assisted dissolution.

[0070] Preferably, in step (2), the enzyme used for enzymolysis is at least one of papain, proteinase K, trypsin, and pronase; further preferably, the enzyme is papain.

[0071] Preferably, the concentration of the enzyme during the enzymatic hydrolysis is 0.1-2.0%; further preferably, 0.1-1%, 0.5-1.5%, 0.5-1%; more preferably, the concentration of the protease is 1.5%.

[0072] Preferably, in step (2), the purification treatment comprises adsorption and dialysis.

[0073] The adsorption method includes, but is not limited to, adsorption of fat-soluble components by non-polar macroporous resin, activated carbon adsorption, silica gel adsorption, etc. Further preferably, the adsorption method is adsorption of fat-soluble components by non-polar macroporous resin, further preferably macroporous resin AB-8. Further preferably, the dialysis is dialysis for 24-72 h using a dialysis bag with a molecular weight cut-off of 3000 Da, further preferably dialysis for 48 h using a dialysis bag with a molecular weight cut-off of 3000 Da.

[0074] Further preferably, the purification treatment further comprises drying.

[0075] The drying method includes, but is not limited to, freeze-drying, oven drying, air drying, blow drying, natural drying, vacuum drying, etc.; further preferably, the drying method is freeze-drying.

[0076] Preferably, the method for preparing the crude corchorus olitorius polysaccharide comprises the following steps: (1) Take dried corchorus olitorius leaves, add water at a solid-liquid ratio of 1:8, and reflux extract twice, each for 2 h; combine the extract, concentrate, add 95% ethanol to a content of 80%, and let stand overnight at room temperature to precipitate, remove the supernatant, wash the precipitate with 95% ethanol until there is no alcohol smell, and dry to obtain the crude corchorus olitorius polysaccharide; (2) Remove impurities from the crude corchorus olitorius polysaccharide: Dissolve the crude corchorus olitorius polysaccharide obtained in step (1) in pure water, ultrasonicate to fully dissolve, add 1.5% papain, and hydrolyze overnight to obtain an enzyme hydrolysate; (3) Add chloroform and n-butanol to the enzyme hydrolysate, mix thoroughly, and collect the upper aqueous phase; (4) Add petroleum ether to the aqueous phase to extract, and collect the lower aqueous phase; (5) Add macroporous resin AB-8 to the aqueous phase, mix thoroughly, and adsorb overnight; (6) Collect the liquid, dialyze for 48 h using a 3000 Da dialysis bag to remove small molecule components, freeze-dry the polysaccharide solution to obtain the crude corchorus olitorius polysaccharide.

[0077] Based on further solving or simultaneously solving multiple technical problems of the technical problem of the present application, in the technical solution provided in the second aspect of the present application, the preferred solution comprises: The first preferred solution, the solvent for ion exchange purification is selected from at least one of water, sodium chloride, further preferably, the solvent is selected from at least one of water, sodium chloride solution; more preferably, the solvent is water. The technical solution further solves the technical problem of "further improving the purification rate of uniform polysaccharide of jute" on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide of jute".

[0078] The second preferred solution, the ion exchange column type for ion exchange purification is selected from any one of Cellulose DEAE-cellulose column, aminoethyl cellulose column, Q Sepharose gel column, SP Sepharose gel column. Further preferably, the ion exchange column is selected from any one of Cellulose DEAE-52, Cellulose DEAE-22, Cellulose DEAE-23, Cellulose DEAE-32, Cellulose DEAE-11; more preferably, the ion exchange column is Cellulose DEAE-52. The technical solution further solves the technical problem of "further improving the purification rate of uniform polysaccharide of jute" on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide of jute".

[0079] The third preferred solution, the flow rate through the ion exchange column is selected from 2-6 mL / min, further preferably 4 mL / min. The technical solution further solves the technical problem of "further improving the purification rate of uniform polysaccharide of jute" on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide of jute".

[0080] The fourth preferred solution, the elution condition is selected from gradient elution with pure water, 0.05-0.15M, 0.15-0.25M and 0.25-0.35M NaCl solution in turn, further preferably: gradient elution with pure water, 0.1M, 0.2M and 0.3M NaCl solution in turn; more preferably, elution with 0.1M NaCl solution. The technical solution further solves the technical problem of "further improving the purification rate of uniform polysaccharide of jute" on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide of jute".

[0081] The fifth preferred solution, the dialysis condition is selected from dialysis for 30-60h with a dialysis bag with a molecular weight cut-off of 3000Da, further preferably: dialysis for 48h with a dialysis bag with a molecular weight cut-off of 3000Da. The technical solution further solves the technical problem of "further improving the purification rate of uniform polysaccharide of jute" on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide of jute".

[0082] The sixth preferred solution, the solvent for gel chromatography purification is selected from at least one of water, phosphate buffer, NaCl solution, Tris-HCl buffer. Further preferably, the solvent is water, NaCl solution; more preferably, water. This technical solution further improves the purification rate of uniform polysaccharide from jute on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide from jute".

[0083] The seventh preferred solution, the concentration of the mother liquor is selected from 1-10 mg / mL, further preferably 2 mg / mL. This technical solution further improves the purification rate of uniform polysaccharide from jute on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide from jute".

[0084] The eighth preferred solution, the type of gel chromatography column is selected from at least one of cross-linked dextran gel (Sephadex series), agarose gel (Sepharose / Superose series), polyacrylamide gel (Bio-Gel P series), composite gel; further preferably, at least one of Sephadex G-75, Sephadex G-100, Superose 12, Superdex 200 10 / 300 GL; more preferably, Superdex 200 10 / 300 GL. This technical solution further improves the purification rate of uniform polysaccharide from jute on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide from jute".

[0085] The ninth preferred solution, the flow rate through the gel chromatography column is selected from 0.5-2 mL / min, further preferably 1 mL / min. This technical solution further improves the purification rate of uniform polysaccharide from jute on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide from jute".

[0086] The tenth preferred solution, the elution volume range is selected from 1.0-2.0 times the column volume, further preferably 1.5 times the column volume. This technical solution further improves the purification rate of uniform polysaccharide from jute on the basis of solving the technical problem of "improving the purification rate of uniform polysaccharide from jute".

[0087] Eleventh preferred solution, the solvent for extracting the jute leaves is selected from at least one of water, 0.1-1M HCl solution, 0.1-1M NaOH solution, NaCl solution; further preferably: at least one of water, 0.1-1M HCl solution, 0.1-1M NaOH solution; more preferably water; most preferably water with a temperature of 60-100℃. This technical solution, on the basis of solving the technical problem of "improving the purification rate of jute uniform polysaccharide", further solves the technical problem of "further improving the purification rate of jute uniform polysaccharide".

[0088] Twelfth preferred solution, the alcohol content of the alcohol precipitation treatment solution is selected from 80%-90%, further 80%. This technical solution, on the basis of solving the technical problem of "improving the purification rate of jute uniform polysaccharide", further solves the technical problem of "further improving the purification rate of jute uniform polysaccharide".

[0089] Thirteenth preferred solution, the solvent for removing impurities from jute crude polysaccharide is selected from water and NaCl solution, further preferably water. This technical solution, on the basis of solving the technical problem of "improving the purification rate of jute uniform polysaccharide", further solves the technical problem of "further improving the purification rate of jute uniform polysaccharide".

[0090] Fourteenth preferred solution, the ratio of jute crude product to water is selected from 1:50-1:120, further preferably 1:100. This technical solution, on the basis of solving the technical problem of "improving the purification rate of jute uniform polysaccharide", further solves the technical problem of "further improving the purification rate of jute uniform polysaccharide".

[0091] Fifteenth preferred solution, the type of protease is selected from at least one of papain, protease K, trypsin, and pronase, further preferably papain. This technical solution, on the basis of solving the technical problem of "improving the purification rate of jute uniform polysaccharide", further solves the technical problem of "further improving the purification rate of jute uniform polysaccharide".

[0092] Sixteenth preferred solution, the concentration of the protease is selected from 0.1-1%, 0.5-1.5%, and 0.5-1%, further preferably 0.1-1%, 0.5-1.5%, and 0.5-1%; more preferably 1.5%. This technical solution, on the basis of solving the technical problem of "improving the purification rate of jute uniform polysaccharide", further solves the technical problem of "further improving the purification rate of jute uniform polysaccharide".

[0093] Third aspect, the present application provides: the use of the above-mentioned jute uniform polysaccharide in the preparation of immunomodulatory drugs.

[0094] Among them, the technical features include: the use of the above-mentioned jute uniform polysaccharide.

[0095] The application of the uniform polysaccharide from Corchorus capsu- laris L. is preferably: the immunoregulation is to enhance the immune suppression induced by cyclophosphamide, the enhanced immunity is to improve the immune organ index, restore the morphological characteristics and blood cell number of the spleen, promote the production of immune and inflammatory cytokines, and restore the immune function of the mice.

[0096] In a fourth aspect, the present application provides: an immunoregulatory pharmaceutical composition, the active ingredient of which comprises the uniform polysaccharide from Corchorus capsularis L. and one or more pharmaceutically acceptable carriers, diluents, excipients.

[0097] The technical features include: the uniform polysaccharide from Corchorus capsularis L., the pharmaceutically acceptable carrier, the diluent, and the excipient.

[0098] In the pharmaceutical composition, the term "composition" includes a product containing the active ingredient and the inert ingredient (pharmaceutically acceptable excipient) of the constituent carrier, and any product directly or indirectly obtained from the combination, complexation or aggregation of two or more ingredients, or the decomposition of one or more ingredients, or other types of reactions or interactions of one or more ingredients. Therefore, the pharmaceutical composition of the present application includes any composition prepared by mixing the uniform polysaccharide from Corchorus capsularis L., other active ingredients and pharmaceutically acceptable excipients.

[0099] The pharmaceutical composition of the present application comprises the uniform polysaccharide from Corchorus capsularis L. as the active ingredient, the pharmaceutically acceptable carrier and optionally other therapeutic ingredients or adjuvants.

[0100] The pharmaceutical composition includes compositions suitable for oral, rectal, topical, and parenteral (including subcutaneous, intramuscular, and intravenous) administration, although the most suitable route in any given case will depend on the particular subject, the nature and severity of the condition for which the active ingredient is being administered. The pharmaceutical composition can be prepared by any method known in the art of pharmacy.

[0101] The uniform polysaccharide from Corchorus capsularis L. can have a synergistic immunoregulatory effect with other active ingredients, or enhance the efficacy against specific diseases (such as tumors, autoimmune diseases, infectious diseases, etc.), and the other active ingredients include immune checkpoint modulators, cytokines and cytokine modulators, vaccines and antigen components, other natural source immunoregulators, small molecule immunoregulators, cytokines or growth factors, etc.

[0102] The immune checkpoint modulators mentioned above refer to the enhancement of T cell activity by blocking immune suppression pathways (such as PD-1 / PD-L1, CTLA-4), and the synergistic activation of anti-tumor or anti-infection immunity with uniform corchorus capsularis polysaccharide, such as PD-1 inhibitors, PD-L1 inhibitors, CTLA-4 inhibitors, LAG-3 inhibitors. The above-mentioned cytokines and cytokine modulators enhance the immune regulation effect of uniform corchorus capsularis polysaccharide by regulating immune cell proliferation, differentiation or cytokine secretion, such as pro-inflammatory cytokines: interleukin-2 (IL-2, promoting T cell proliferation), interferon-γ (IFN-γ, enhancing NK cell and macrophage activity).

[0103] Anti-inflammatory cytokines: interleukin-10 (IL-10, used in autoimmune diseases to balance excessive immune response), etc. The above-mentioned vaccines and antigen components refer to infectious diseases or tumors, and uniform corchorus capsularis polysaccharide can be used as an adjuvant to enhance the immunogenicity of vaccines, such as tumor antigens: tumor-related peptides (such as HPV E6 / E7 peptides, melanoma antigen MART-1), tumor cell lysates; pathogen antigens: viral antigens (such as new coronavirus S protein, influenza virus hemagglutinin), bacterial antigens (such as Mycobacterium tuberculosis ESAT-6 protein), parasitic antigens (such as Plasmodium CSP protein). The above-mentioned other natural source immune modulators regulate immunity through multiple targets, reduce the dosage and side effects of single components, such as plant polysaccharides: lentinan (enhancing NK cell activity), ganoderma polysaccharide (regulating Th1 / Th2 balance), astragalus polysaccharide (promoting B cell proliferation); plant extracts: ginsenoside Rg3 (inhibiting tumor angiogenesis), curcumin (anti-inflammatory and immune regulation); microbial-derived components: yeast beta-glucan (activating macrophages), lactic acid bacteria cell wall peptides (regulating intestinal mucosal immunity). The above-mentioned small molecule immune modulators enhance immune response or inhibit excessive activation by regulating immune cell signaling pathways (such as NF-κB, JAK-STAT), such as JAK inhibitors: tofacitinib (used in autoimmune diseases to inhibit excessive immune response), ruxolitinib (regulating inflammatory factor secretion); TLR agonists: imiquimod (activating TLR7 to enhance innate immunity), CpG oligonucleotide (activating TLR9 to promote cytokine secretion); metabolic modulators: metformin (regulating immune cell metabolism through the AMPK pathway to enhance anti-tumor immunity). The above-mentioned cytokines or growth factors directly supplement immune active molecules and synergize with uniform corchorus capsularis polysaccharide to amplify immune effects, such as pro-inflammatory cytokines: interleukin-12 (IL-12, promoting Th1 cell differentiation), tumor necrosis factor-α (TNF-α, enhancing tumor cell apoptosis); colony stimulating factors: granulocyte-macrophage colony stimulating factor (GM-CSF, promoting dendritic cell maturation), granulocyte colony stimulating factor (G-CSF, enhancing the anti-infection ability of neutrophils).

[0104] The active ingredients can be administered orally in solid dosage forms, such as capsules, tablets, troches, dragees, granules, and powders, or in liquid dosage forms, such as elixirs, syrups, emulsions, dispersions, and suspensions. The active ingredients can also be administered parenterally, in sterile liquid dosage forms, such as dispersions, suspensions, or solutions. Other dosage forms that can be used to administer the active ingredients include ointments, creams, drops, transdermal patches, or powders for topical administration; eye solutions or suspensions, i.e., eye drops, for ocular administration; spray or powder compositions for inhalation or intranasal administration; or creams, ointments, sprays, or suppositories for rectal or vaginal administration. Gelatin capsules include the active ingredient and a powdered carrier, such as lactose, starch, cellulose derivatives, magnesium stearate, stearic acid, and the like. Similar diluents can be used to make compressed tablets. Both tablets and capsules can be manufactured to provide slow or delayed release of the drug for hours in order to provide a sustained release of the drug. Compressed tablets can be sugar-coated or film-coated to mask any unpleasant taste and to protect the tablet from the atmosphere, or can be enteric-coated for selective disintegration in the gastrointestinal tract. Liquid dosage forms for oral administration can include colorants and flavoring agents to increase patient acceptance. In general, water, suitable oils, saline, dextrose (glucose) in water, and related sugar solutions and glycols, such as propylene glycol or polyethylene glycol, are suitable carriers for parenteral solutions. Solutions for parenteral administration preferably include water-soluble salts of the active ingredient, suitable stabilizing agents, and if necessary, buffer substances. Antioxidants, such as sodium bisulfite, sodium sulfite, or ascorbic acid, alone or combined, are suitable stabilizing agents. Citric acid and its salts and EDTA sodium can also be used. In addition, parenteral solutions can include preservatives, such as benzalkonium chloride, nipagin, or nipasol, and chlorobutanol. For inhalation administration, the compounds of the present application can be conveniently delivered in the form of an aerosol spray from pressurized packs or a nebulizer. The compounds can also be delivered in the form of a powder for formulation as an inhaler, which can be inhaled with the aid of an insufflation powder inhaler device. The preferred delivery system for inhalation is a metered dose inhaler (MDI) aerosol, which can be formulated as a suspension or solution of the compound of Formula I in a suitable propellant, such as a fluorocarbon or a hydrocarbon. For ocular administration, the ophthalmic formulation can be formulated with a suitable percentage by weight of the compound in a solution or suspension of a suitable ophthalmic carrier, such as a uniform polysaccharide of jute, to maintain contact of the compound with the surface of the eye for a sufficient time for the compound to penetrate the cornea and internal regions of the eye.

[0105] Useful pharmaceutical dosage forms for administration of the compounds of the application include, but are not limited to, hard and soft gelatin capsules, tablets, parenteral injectable solutions and oral suspensions. The same dosage forms as described above can be used when the jute uniform polysaccharide of the application is administered gradually or in combination with other therapeutic agents. When the drugs are administered in a physical combination, the dosage form and the route of administration should be selected according to the compatibility of the combined drugs. The jute uniform polysaccharide of the application can be administered as the only active ingredient or in combination with a second active ingredient, including an active ingredient known to be useful for increasing the patient's erythropoietin level.

[0106] The present application has at least the following beneficial effects: (1) The present application provides a new jute uniform polysaccharide CCP-D2N1 and characterizes its structure, which is composed of rhamnose, arabinose, galactose and galacturonic acid in a molar ratio of 45.32:12.87:24.17:17.64, and the weight average molecular weight Mw is 73.897 kDa; (2) The jute uniform polysaccharide has significant immune activation properties. In the CTX-induced immunosuppressed mouse model, it can increase the immune organ index, restore the morphological characteristics and blood cell number of the spleen, promote the production of immune and inflammatory cytokines, and restore the immune function of the mouse. Mechanism studies show that CCP-D2N1 can enhance the immune function in vivo through the TLR4-mediated MAPK and NF-κB signaling pathways.

[0107] (3) Compared with the prior art, the present application has better technical effects in improving the extraction rate of jute uniform polysaccharide, increasing the immune organ index, and restoring the immune function of the mouse.

[0108] In addition, based on the case of the present application: Based on the comparison of Example 1 and Comparative Examples 1-3, the present application uses the technical means "elution of ion exchange purification eluent is 0.1M NaCl solution", which significantly improves the purity of the obtained jute uniform polysaccharide, and solves the technical problem "further improve the purification rate of jute uniform polysaccharide".

[0109] Based on the consideration of the present application into other countries, the present application further provides the following technical solutions: An immune regulation method, comprising administering the above jute uniform polysaccharide to an individual.

[0110] In some embodiments, the administration is intragastric administration.

[0111] Preferably, the dose administered to the individual is 20-1000 mg / day.

[0112] Preferably, for example, 20-100 mg / day, 100-200 mg / day, 200-300 mg / day, 300-400 mg / day; More preferably, for example, 20-50 mg / day, 50-100 mg / day, 100-150 mg / day, 150-200 mg / day, 200-250 mg / day, 250-300 mg / day, 300-350 mg / day, 350-400 mg / day, 400-450 mg / day, 450-500 mg / day.

[0113] More preferably, for example, 20 mg / day, 30 mg / day, 40 mg / day, 50 mg / day, 60 mg / day, 70 mg / day, 80 mg / day, 100 mg / day, 110 mg / day, 120 mg / day, 130 mg / day, 140 mg / day, 150 mg / day, 160 mg / day, 170 mg / day, 180 mg / day, 190 mg / day, 200 mg / day, 210 mg / day, 220 mg / day, 230 mg / day, 240 mg / day, 250 mg / day, 260 mg / day, 270 mg / day, 280 mg / day, 290 mg / day, 300 mg / day, 310 mg / day, 320 mg / day, 330 mg / day, 340 mg / day, 350 mg / day, 360 mg / day, 370 mg / day, 380 mg / day, 390 mg / day, 400 mg / day.

[0114] "Individual" refers to an individual having a disease, disorder, or condition, and the like, including mammals and non-mammals. Examples of mammals include, but are not limited to, any member of the mammalian class: humans, non-human primates (e.g., chimpanzees and other apes and monkeys); farm animals such as cattle, horses, sheep, goats, swine; domestic animals such as rabbits, dogs, and cats; laboratory animals including rodents, such as rats, mice and guinea pigs, and the like. Examples of non-human mammals include, but are not limited to, birds and fish, and the like. In one embodiment of the methods and compositions provided herein, the mammal is a human. BRIEF DESCRIPTION OF DRAWINGS

[0115] Figure 1 Elution profile for ion-exchange chromatography purification of uniform corchorus polysaccharide; Figure 2 Elution profile for gel filtration chromatography purification of corchorus polysaccharide fraction CCP-D2; Figure 3 Graphical analysis of absolute molecular weight of uniform corchorus polysaccharide CCP-D2 N1; Figure 4 Graphical analysis of molecular configuration of uniform corchorus polysaccharide CCP-D2 N1; Figure 5Ion chromatogram of mixed standard; Figure 6 Ion chromatogram of uniformed polysaccharide CCP-D2N1 from Corchorus capsu- laris L; Figure 7 GC-MS total ion chromatogram of uniformed polysaccharide CCP-D2N1 from Cor- chorus capsularis L; Figure 8 Effect of uniformed polysaccharide CCP-D2N1 from Corchorus capsularis L on RAW264.7 cell proliferation; Figure 9 Effect of uniformed polysaccharide CCP-D2N1 from Corchorus capsularis L on RAW264.7 cell phagocytosis (compared with blank group, ##: P<0.01); Figure 10 Effect of uniformed polysaccharide CCP-D2N1 from Corchorus capsularis L on RAW264.7 cell secretion of cytokines (compared with blank group, ##: P<0.01; ###: P<0.001); Figure 11 NMR one-dimensional H spectrum of uniformed polysaccharide CCP-D2N1 from Cor- chorus capsularis L; 1 Figure 12 NMR one-dimensional C spectrum of uniformed polysaccharide CCP-D2N1 from Cor- chorus capsularis L; 13 Figure 13 NMR two-dimensional COSY spectrum of uniformed polysaccharide CCP-D2N1 from Cor- chorus capsularis L; Figure 14 NMR two-dimensional NOESY spectrum of uniformed polysaccharide CCP-D2N1 from Cor- chorus capsularis L; Figure 15 NMR two-dimensional HSQC spectrum of uniformed polysaccharide CCP-D2N1 from Cor- chorus capsularis L; Figure 16 NMR two-dimensional HMBC spectrum of uniformed polysaccharide CCP-D2N1 from Cor- chorus capsularis L; Figure 17 Effect of uniformed polysaccharide CCP-D2N1 from Corchorus capsularis L on body weight and immune organ index of immunosuppressed mice (compared with blank group, ###: P<0.001; compared with model group, *: P<0.05; **: P<0.01; ***: P<0.001); Figure 18 Effect of uniformed polysaccharide CCP-D2N1 from Corchorus capsularis L on patho- logical characteristics of spleen of immunosuppressed mice; Figure 19 Effect of uniformed polysaccharide CCP-D2N1 from Corchorus capsularis L on immune cytokines in spleen of mice (compared with blank group, ###: P<0.001; compared with model group, *: P<0.05; **: P<0.01; ***: P<0.001); Figure 20 ​​Effect of uniform polysaccharide CCP-D2N1 from Corchorus capsu- laris L. on the number of blood cells in mice (compared with the blank group, ###: P<0.001; compared with the model group, *: P<0.05; **: P<0.01; ***: P<0.001); Figure 21 Effect of uniform polysaccharide CCP-D2N1 from Corchorus capsu- laris L. on the number of blood cells in mice (compared with the blank group, ###: P<0.001; compared with the model group, *: P<0.05; **: P<0.01; ***: P<0.001); Figure 22 Effect of uniform polysaccharide CCP-D2N1 from Corchorus capsu- laris L. on the number of blood cells in mice (compared with the blank group, ###: P<0.001; compared with the model group, *: P<0.05; **: P<0.01; ***: P<0.001). DETAILED DESCRIPTION

[0116] The following non-limiting examples can make the ordinary skilled in the art more comprehensive understanding of the present application, but not in any way limit the present application. The following content is only an exemplary description of the scope of the present application, those skilled in the art can make various changes and modifications to the present application according to the disclosed content, and it should also belong to the scope of the present application claimed.

[0117] The following is a further description of the present application in the form of specific examples. The various instruments, devices, equipment, reagents, products, etc. used in the examples of the present application, such as no special description are obtained by conventional commercial channels.

[0118] Example 1: Preparation of uniform polysaccharide CCP-D2N1 from Cor- chorus capsularis L. I. Extraction of crude polysaccharide from Corchorus capsularis L. Take 2 kg of dried Corchorus capsularis L. leaves, add water according to the ratio of 1:8, reflux extraction 2 times, 2 h each time; combine the extract, concentrate to 4 L, add 95% ethanol to make the ethanol content reach 80%, place at room temperature overnight to precipitate, remove the supernatant, wash the precipitate with 8 L of 95% ethanol until there is no alcohol smell, dry, and get the crude polysaccharide from Corchorus capsularis L.

[0119] II. Impurity removal of crude polysaccharide from Corchorus capsularis L. (1) Dissolve 30g of jute crude polysaccharide in 3L of pure water, sonicate to dissolve it completely, add 1.5% papain (100,000 U / g), and enzymatically hydrolyze overnight to obtain the enzymatic hydrolysate; (2) Add 750mL each of chloroform and n-butanol to the enzymatic hydrolysate (aqueous phase), mix thoroughly, and collect the upper aqueous phase; (3) Add 1.5L of petroleum ether to the aqueous phase for extraction, and collect the lower aqueous phase; (4) Add AB-8400g of macroporous resin to the aqueous phase, mix thoroughly, and adsorb overnight; (5) Collect the liquid, and dialyze it with a dialysis bag (3000Da) for 48h to remove small molecule components. Freeze-dry the polysaccharide solution to obtain 5.5g of jute crude polysaccharide sample after impurity removal, with a purity of 60.4%.

[0120] III. Ion Exchange Purification: (1) Dissolve the purified jute crude polysaccharide sample in pure water to prepare a jute crude polysaccharide mother liquor of 20 mg / mL; (2) Centrifuge the jute crude polysaccharide mother liquor at 10000 r / min for 10 min, take the supernatant and purify it through an ion exchange column CelluloseDEAE-52 at a flow rate of 4 mL / min; elute with 0.1 M NaCl solution, collect one tube for every 15 mL, collect all the eluent and record it as D2; (3) Accurately measure an appropriate amount of eluent in each collection tube, add sulfuric acid-phenol reagent, react in the dark for 10 min, measure the absorbance at 490 nm, and determine the total sugar content using the sulfuric acid-phenol method; plot the ion purification elution curve of the sample with the number of eluent tubes as the abscissa and the total sugar content and the NaCl concentration in the eluent as the ordinate (see Figure 1 (4) Combine the eluents from the collection tubes corresponding to the same elution peak; (5) Concentrate the collected eluent to 1 / 5 of its original volume; (6) Dialyze with a dialysis bag with a molecular weight cutoff of 3000 Da for 48 hours, and freeze-dry the dialyzed solution to obtain the jute polysaccharide component CCP-D2.

[0121] IV. Gel filtration chromatography purification: (1) Take 1.0 g of the purified jute polysaccharide component CCP-D2 and add pure water to prepare a 2 mg / mL jute polysaccharide component CCP-D2 stock solution; (2) Take 10 g of the jute polysaccharide component CCP-D2 stock solution and centrifuge at 10000 r / min for 10 min. Take the supernatant and separate and purify it through a gel chromatography column Superdex20010 / 300GL at a flow rate of 1 mL / min. Elute with pure water at a volume of 1.5 times the column volume. Collect one tube for every 12 mL and collect all the eluent; (3) Determine the total sugar content of the eluent in each collection tube using the sulfuric acid-phenol method. Plot the gel purification elution curve of the sample with the number of eluent tubes as the abscissa and the total sugar content as the ordinate (see Figure 2 ); Depend on Figure 2It can be seen that the gel filtration chromatography purification mainly obtained one elution peak component, gel elution peak 1: 23-41 tube, recorded as CCP-D2N1; (4) The eluent of each collection tube corresponding to the elution peak was combined, and concentrated to 1 / 5 of the original volume; (5) Freeze-drying, and using the sulfuric acid-phenol method to identify the polysaccharide content and purity after gel purification, obtaining the jute homogeneous polysaccharide CCP-D2N1 0.60g, the purity is 94.2%.

[0122] Example 2 Preparation of jute polysaccharide CCP-D1 The difference between Example 1 and Example 2 is that the eluent of ion exchange purification is replaced with pure water, and there is no gel filtration chromatography purification step, and the rest is the same. Obtaining the jute polysaccharide CCP-D1 0.986g, the purity is 52.1%.

[0123] Example 3 Preparation of jute polysaccharide CCP-D3 The difference between Example 1 and Example 3 is that the eluent of ion exchange purification is replaced with 0.2M NaCl solution, and there is no gel filtration chromatography purification step, and the rest is the same. Obtaining the jute polysaccharide CCP-D3 0.120g, the purity is 67.3%.

[0124] Example 4 Preparation of jute polysaccharide CCP-D4 The difference between Example 1 and Example 4 is that the eluent of ion exchange purification is replaced with 0.3M NaCl solution, and there is no gel filtration chromatography purification step, and the rest is the same. Obtaining the jute polysaccharide CCP-D4 0.045g, the purity is 84.8%.

[0125] Detection Example 1: Study on the in vitro immunomodulatory effect of jute polysaccharide components (1) RAW264.7 cell culture: RAW264.7 cells were cultured in DMEM medium (containing 10% fetal bovine serum, 100U / mL penicillin and 100μg / mL streptomycin) at 37℃, 5% CO2 incubator, and the cell culture medium was replaced every 3 days.

[0126] (2) Effect of jute polysaccharide components on RAW264.7 cell proliferation: Selecting cells in the logarithmic growth phase, 5×104 / mL, 100 μL / well inoculated in 96-well plates, incubated overnight in a CO2incubator, then add the ion exchange purified CCP-D1, CCP-D2, CCP-D3 and CCP-D4 solution of Example 1 each 100 μL (50 μg / mL), the blank control group (NC group) without drug, add the same volume of drug solvent. Another background control wells, 6 replicates in each group, 37℃ incubated for 24h, then add 10µL CCK-8 solution to each well and continue to incubate for 1h, measure the absorbance at 450nm. The cell survival rate was calculated according to the following formula: Cell survival rate = (OD experimental well-OD background well) / (OD blank well-OD background well) × 100%.

[0127] The results of the effect of jute polysaccharide components on RAW264.7 cell proliferation are shown in Figure 8 . As can be seen from the figure, 50 μg / mL jute polysaccharide components CCP-D1 (obtained in Example 2), CCP-D2 (obtained in Example 1), CCP-D3 (obtained in Example 3) and CCP-D4 (obtained in Example 4) have no cytotoxicity on RAW264.7, so 50 μg / mL sample concentration is used for subsequent experiments.

[0128] (3) Determination of the phagocytic ability of jute polysaccharide components on RAW264.7 cells: Selecting cells in the logarithmic growth phase, 2.5×104 / mL, 100 μL / well inoculated in 96-well plates, incubated overnight in a CO2incubator, then add the ion exchange purified CCP-D1 of Example 2, the ion exchange purified CCP-D2 of Example 1, the ion exchange purified CCP-D3 of Example 3 and the ion exchange purified CCP-D4 of Example 4 solution each 100 μL (50 μg / mL), continue to incubate for 24h, with DMEM medium as blank control group, LPS (1 μg / mL) as positive control group. After incubation, discard the supernatant, wash twice with pre-cooled PBS, then add 1% neutral red dye solution to the incubator and incubate for 1h. Then remove the neutral red, wash twice with PBS, then add cell lysis solution (50% ethanol, 1% acetic acid) to extract neutral red, and detect the absorbance at 540nm. The results of the effect of jute polysaccharide components on the phagocytic ability of RAW264.7 cells are shown in Figure 9 . The four components of jute polysaccharide components all improve the phagocytic ability of RAW264.7 cells, and CCP-D2 has the strongest activity, higher than the positive control drug LPS group.

[0129] (4) Effect of jute polysaccharide components on the release of NO and cytokines by RAW264.7 cells: The cells in logarithmic growth phase were inoculated in 96-well plates at 5×105 / mL, 100 μL / well, and then placed in a CO2incubator overnight. The culture solution was discarded, and serum-free DMEM solution was added for 2 h of starvation culture to make the cells at the same level. The experimental group was added with 100 μL (50 μg / mL) of CCP-D1 obtained by ion exchange purification in Example 2, CCP-D2 obtained by ion exchange purification in Example 1, CCP-D3 obtained by ion exchange purification in Example 3, and CCP-D4 obtained by ion exchange purification in Example 4, respectively. The DMEM medium was used as a blank control group, and LPS (1 μg / mL) was used as a positive control group. After 24 h of culture, the cell supernatant was collected for determination of the NO and cytokine production. The NO was determined using Griess reagent, and the cytokine production was determined using an ELASA kit. The effects of different components of corchorus capsularis polysaccharides on the secretion of NO, TNF-α, IL-6, and IL-10 by RAW264.7 cells Figure 10 as shown.

[0130] The results showed that, compared with the blank control group, the release amount of NO, IL-6, and TNF-α by RAW264.7 cells was significantly increased after treatment with the four components of corchorus capsularis polysaccharides, indicating that the four components of corchorus capsularis polysaccharides had certain immune activation properties. Among them, the immune activation property of corchorus capsularis polysaccharide component CCP-D2 was stronger (P<0.001), which was equivalent to the positive control drug LPS group, and had the potential to develop into an immunomodulator.

[0131] In summary, the four components of corchorus capsularis polysaccharides CCP-D1, CCP-D2, CCP-D3, and CCP-D4 could enhance the phagocytic ability of RAW264.7 cells, and could play an immunomodulatory role by promoting the release of cytokines such as NO, TNF-α, and IL-6. Among them, corchorus capsularis polysaccharide component CCP-D2 showed the strongest immunomodulatory activity, and therefore CCP-D2N1 was further purified. Detection Example 2: Structure identification of corchorus capsularis uniform polysaccharide CCP-D2N1 (1) The molecular weight of corchorus capsularis uniform polysaccharide CCP-D2N1 was determined by high-performance gel chromatography: (a) Chromatographic conditions: Gel permeation chromatography-differential multi-angle laser light scattering system: liquid phase system is U3000 (Thermo, USA), differential detector is OptilabT-rex (Wyatt technology, CA, USA), laser light scattering detector is DAWN HELEOS II (Wyatt technology, CA, USA); gel exclusion chromatography column Ohpak SB-805HQ (300x8mm) and Ohpak SB-803HQ (300x8mm) are connected in series; column temperature: 45℃; injection volume: 100 μL; mobile phase: 0.02wt% NaN3, 0.1M NaNO3; flow rate: 0.6mL / min; isocratic elution: 75min.

[0132] (b) Sample preparation: the sample is dissolved in 0.1M NaNO3 aqueous solution (containing 0.02% NaN3, w / w) to a final concentration of 1mg / mL, and then filtered through a filter with a pore size of 0.45 μm before being detected by the machine.

[0133] (c) Determination results: the absolute molecular weight analysis diagram is shown in Figure 3 , and the molecular configuration analysis diagram is shown in Figure 4 ; the weight average molecular weight Mw of the uniform polysaccharide CCP-D2N1 of jute is calculated according to the Mark-Houwink Equation to be 73.897kDa.

[0134] (2) The composition of the uniform polysaccharide CCP-D2N1 of jute is analyzed by using an ion chromatograph. (a) Chromatographic conditions: Chromatographic system: Thermo ICS5000+ ion chromatography system (ICS5000+, Thermo Fisher Scientific, USA) was used to analyze and detect monosaccharide components by using an electrochemical detector; liquid chromatography column Dionex™ CarboPac™ PA20 (150*3.0mm, 10μm); sample injection amount: 5μL; mobile phase: mobile phase A is H2O, mobile phase B is 0.1M NaOH, mobile phase C is 0.1M NaOH (containing 0.2M NaAc); flow rate: 0.5mL / min; column temperature: 30℃; elution gradient: 0min: A phase / B phase / C phase (95:5:0, V / V); 26min: A phase / B phase / C phase (85:5:10, V / V); 42min: A phase / B phase / C phase (85:5:10, V / V); 42.1min: A phase / B phase / C phase (60:0:40, V / V); 52min: A phase / B phase / C phase (60:40:0, V / V); 52.1min: A phase / B phase / C phase (95:5:0, V / V); 60min: A phase / B phase / C phase (95:5:0, V / V).

[0135] (b) Preparation of standard solution and calculation method: Take 13 kinds of monosaccharide standard (fucose (Fuc), rhamnose (Rha), arabinose (Ara), galactose (Gal), glucose (Glc), xylose (Xyl), mannose (Man), fructose (Fru), ribose (Rib), galacturonic acid (Gal-UA), glucuronic acid (Glc-UA), mannuronic acid (Man-UA), guluronic acid (Gul-UA)), prepare about 10mg / mL standard stock solution; take appropriate amount of standard stock solution to prepare a standard mixed label with the highest index concentration of 60μg / mL, 50μg / mL or 40μg / mL, and prepare a series of standard samples required for the machine according to the concentration gradient in Table 1.

[0136] Table 1. Monosaccharide mixed label series concentration table

[0137] (c) Acid hydrolysis: take 5.04mg of jute homogeneous polysaccharide CCP-D2N1 sample, add 2M TFA (1mL) solution, heat at 121℃ for 2 hours; blow dry under nitrogen; add 99.99% methanol to wash, and then blow dry, repeat the methanol washing for 3 times. Dissolve in distilled water and perform ion chromatography detection.

[0138] (d) Determination results: The results of ion chromatogram of mixed standard and jute homogeneous polysaccharide CCP-D2N1 are shown in Figure 5 , Figure 6 .

[0139] Content of each component in sample (μg / mg) = C*V*F / M, Wherein: C is the concentration, unit μg / mL; V is the sample extraction liquid volume, unit mL; F is the dilution factor; M is the total sample weight, unit mg.

[0140] After calculation, compared with monosaccharide standard, it is concluded that the uniform polysaccharide CCP-D2N1 of jute is a polysaccharide composed of rhamnose, arabinose, galactose and galacturonic acid; the molar ratio of each monosaccharide in CCP-D2N1 is rhamnose: arabinose: galactose: galacturonic acid 45.32: 12.87: 24.17: 17.64.

[0141] (3) The bonding mode of the glycosidic bond of the uniform polysaccharide CCP-D2N1 of jute was analyzed by methylation and gas chromatography-mass spectrometry (GC-MS) combined analysis: (a) Analysis conditions: Agilent Technologies Inc. (CA, UAS) 7890A-5977B gas chromatograph-mass spectrometer, automatic sampler model G4567A; chromatographic column: BPX70 (30 m x 0.25 mm x 0.25 µm, SGE, Australia); injection volume: 1 µL; split ratio: 10:1; carrier gas: high-purity helium; the initial temperature of the column oven was 140℃ and maintained for 2.0 min, and then programmed to increase to 230℃ at a rate of 3℃ / min, and maintained for 3 min; mass spectrometry conditions: electron impact ion source (EI) and MassHunter workstation, analyte was detected in full scan (SCAN) mode, mass scan range (m / z): 50-350.

[0142] (b) Sample processing: 2 mg of the uniform polysaccharide CCL-D2N1 of jute was taken, 500 μL of DMSO was added for dissolution, 1 mg of NaOH was added, and incubated for 30 min; 50 μL of iodomethane solution was added for reaction for 1 h, then 1 mL of water and 2 mL of dichloromethane were added, vortexed, centrifuged, and the water phase was discarded; the lower dichloromethane phase was collected and blown dry with nitrogen; 100 μL of 2M TFA was added, reacted at 121℃ for 90 min, and evaporated at 30℃; 50 μL of 2M ammonia water and 50 μL of 1M NaBD4 were added, mixed, and reacted at room temperature for 2.5 h, then 20 μL of acetic acid was added to terminate the reaction, blown dry with nitrogen, washed twice with 250 μL of methanol, and blown dry with nitrogen; 250 μL of acetic anhydride was added, vortexed, reacted at 100℃ for 2.5 h, 1 mL of water was added and stood for 10 min, then 500 μL of dichloromethane was added, vortexed, centrifuged, the water phase was discarded, the lower dichloromethane phase was collected, and GC-MS detection was performed.

[0143] (c) Test results: The GC-MS total ion current results of the uniform polysaccharide CCP-D2N1 of jute are shown in Table 1 Figure 7 and Table 2. Table 2. Bonding structure analysis results of the uniform polysaccharide CCP-D2N1 polysaccharide sample of jute

[0144] (4) The attribution of the nuclear magnetic signals of the sugar residues was analyzed by nuclear magnetic resonance spectrum: (a) Instrument conditions: nuclear magnetic resonance spectrometer: Bruker (Germany) 500 MHz; scanning temperature was 25°C; QXI 1H / 31P / 13C / 15N 5mm four-resonance inverse detection probe (Z-gradient, ATM Acc), technical parameters: signal-to-noise ratio (1H): 888, resolution (Hz): 0.32 (rotating); BBFO 1H-19F, 31P-15N, 1H decoupling / observe multi-nuclear forward detection probe (Z-gradient, ATM), technical parameters: signal-to-noise ratio (1H): 798, resolution (Hz): 0.26 (rotating); signal-to-noise ratio (C): 32, resolution (Hz): 0.1. 1 13

[0145] (b) Sample treatment: an appropriate amount of the uniform polysaccharide CCP-D2N1 of jute was fully dissolved in D2O to prepare a polysaccharide solution with a concentration of 40 mg / mL; the solution after dissolution was transferred to a nuclear magnetic tube, and the amount of addition was 0.5 mL.

[0146] (c) Test results: the nuclear magnetic tube was placed in the nuclear magnetic resonance spectrometer to scan one-dimensional 1H spectrum, 1 13 C spectrum, two-dimensional COSY, NOESY, HSQC, and HMBC spectrum, and the results are shown in Table 2. Figures 11-16 .

[0147] The hydrogen spectrum signal of the sample was mainly concentrated in δ3.0~5.5ppm, and multiple coupling signal peaks were identified in the anomeric signal region of δ4.3-5.4ppm, indicating that the sample contained multiple sugar residues, and the chemical shifts of the anomeric hydrogens were δ4.38, 4.53, 4.88, 4.95, 4.98, 5.04, 5.13, 5.14, etc. The non-anomeric hydrogen signal was mainly concentrated in the δ3.1~4.2ppm region, wherein the strong signal peak near δ4.71ppm was the solvent peak. The signal peak near δ3.73ppm was the signal of the hydrogen of O-CH3.

[0148] Multiple signal peaks were identified in the anomeric carbon region of the sample, combined with 13 ​​​The anomeric region of the CNMR and HSQC spectra cross peaks determined the anomeric signals present in the sample were: δ 5.14 / 98.4, 4.38 / 102.9, 4.88 / 97.23, 4.95 / 98.78, 4.53 / 103.97, 4.98 / 107.35, 5.13 / 109.1, 5.04 / 106.92 ppm, and were designated as sugar residues A, B, C, D, E, F, G, H, respectively. Combined with the sample linkage structure (methylation) information, anomeric signals and comprehensive reports in the literature, it was speculated that sugar residue A was →2)-α-L-Rhap-(1→, sugar residue B was →4)-β-D-Galp-(1→, sugar residue C was →4)-α-D-GalpA-(1→, sugar residue D was →4)-α-D-GalpA-6-OMe-(1→, sugar residue E was →3,6)-β-D-Galp-(1→, sugar residue F was α-L-Araf-(1→, sugar residue G was →5)-α-L-Araf-(1→, and sugar residue H was →2,3,5)-α-L-Araf-(1→. The structure of the sample was determined as follows: 1 H and 13 The chemical shifts of C were assigned, and the results are shown in Table 3. The signal peak near δ 52.77 ppm is the signal of the carbon of O-CH3.

[0149] Sugar residue A: The anomeric signal δ 5.14 / 98.4 ppm (H1 / C1) indicated that residue A was likely an α-rhamnose residue. In the COSY spectrum, H2 (4.0 ppm) of residue A was determined according to the cross peak δ 5.14 / 4.0 ppm, H3 (3.8 ppm) of residue A was determined according to the cross peak δ 4.0 / 3.8 ppm, H4 (3.41 ppm) of residue A was determined according to the cross peak δ 3.8 / 3.41 ppm, H5 (3.65 ppm) of residue A was determined according to the cross peak δ 3.41 / 3.65 ppm, and H6 (1.13 ppm) of residue A was determined according to the cross peak δ 3.65 / 1.13 ppm. Combined with the chemical shifts of C on the sugar ring: the chemical shift of C1 of residue A was δ 98.4 ppm, the chemical shift of C2 of residue A was δ 75.98 ppm, the chemical shift of C3 of residue A was δ 68.29 ppm, the chemical shift of C4 of residue A was δ 71.34 ppm, the chemical shift of C5 of residue A was δ 72.91 ppm, and the chemical shift of C6 of residue A was δ 16.41 ppm, wherein the chemical shifts of C1 and C2 shifted to low field, indicating that substitution occurred at the O-1 and O-2 positions of the sugar ring, and combined with the methylation analysis results and literature reports, it was inferred that sugar residue A was likely →2)-α-L-Rhap-(1→; Sugar residue B: anomeric signal δ 4.38 / 102.9 ppm (H1 / C1) indicated that residue B might be a β-galactose residue. In COSY spectrum, H2 (3.25 ppm) of residue B was determined according to cross-peak δ 4.38 / 3.25 ppm, H3 (3.41 ppm) of residue B was determined according to cross-peak δ 3.25 / 3.41 ppm, H4 (3.59 ppm) of residue B was determined according to cross-peak δ 3.41 / 3.59 ppm, H5 (3.98 ppm) of residue B was determined according to cross-peak δ 3.59 / 3.98 ppm, H6 (3.61 ppm) of residue B was determined according to cross-peak δ 3.98 / 3.61 ppm. The chemical shifts of C in the sugar ring were assigned by HSQC signals: the chemical shift of C1 of residue B was δ 102.9 ppm, the chemical shift of C2 of residue B was δ 72.85 ppm, the chemical shift of C3 of residue B was δ 75.4 ppm, the chemical shift of C4 of residue B was δ 75.67 ppm, the chemical shift of C5 of residue B was δ 70.09 ppm, the chemical shift of C6 of residue B was δ 59.34 ppm, wherein the chemical shifts of C1 and C4 shifted to low field, indicating that the residue was substituted at the O-1 and O-4 positions of the sugar ring, and it was inferred that the sugar residue B might be →4)-β-D-Galp-(1→ according to the methylation analysis results and literature reports.

[0150] Sugar residue C: anomeric signal δ 4.88 / 97.23 ppm (H1 / C1) indicated that residue C might be an α-galacturonic acid residue. In COSY spectrum, H2 (3.79 ppm) of residue C was determined according to cross-peak δ 4.88 / 3.79 ppm, H3 (4.0 ppm) of residue C was determined according to cross-peak δ 3.79 / 4.0 ppm, H4 (4.29 ppm) of residue C was determined according to cross-peak δ 4.0 / 4.29 ppm, H5 (4.55 ppm) of residue C was determined according to cross-peak δ 4.29 / 4.55 ppm. The chemical shifts of C in the sugar ring were assigned by HSQC signals: the chemical shift of C1 of residue C was δ 97.23 ppm, the chemical shift of C2 of residue C was δ 69.81 ppm, the chemical shift of C3 of residue C was δ 70.02 ppm, the chemical shift of C4 of residue C was δ 77.51 ppm, the chemical shift of C5 of residue C was δ 71.19 ppm, the chemical shift of C6 of residue C was δ 174.91 ppm, wherein the chemical shifts of C1 and C4 shifted to low field, indicating that the residue was substituted at the O-1 and O-4 positions of the sugar ring, and it was inferred that the sugar residue C might be →4)-α-D-GalpA-(1→ according to the methylation analysis results and literature reports.

[0151] Sugar residue D: anomeric signal δ 4.95 / 98.78 ppm (H1 / C1) indicated that residue D might be an α-galacturonic acid residue. In COSY spectrum, H2 (3.65 ppm) of residue D was determined according to cross-peak δ 4.95 / 3.65 ppm, H3 (3.9 ppm) of residue D was determined according to cross-peak δ 3.65 / 3.9 ppm, H4 (4.31 ppm) of residue D was determined according to cross-peak δ 3.9 / 4.31 ppm. The chemical shifts of C1, C2, C3, C4 of residue D were δ 98.78, 68.24, 68.61, 77.78 ppm respectively by attributing the chemical shifts of C on the sugar ring through HSQC signals. Combined with the results of methylation analysis and literature reports, it was inferred that the sugar residue D might be →4)-α-D-GalpA-6-OMe-(1→.

[0152] Sugar residue E: anomeric signal δ 4.53 / 103.97 ppm (H1 / C1) indicated that residue E might be a β-galactose residue. In COSY spectrum, H2 (3.56 ppm) of residue E was determined according to cross-peak δ 4.53 / 3.56 ppm, H3 (3.62 ppm) of residue E was determined according to cross-peak δ 3.56 / 3.62 ppm, H4 (4.01 ppm) of residue E was determined according to cross-peak δ 3.62 / 4.01 ppm, H5 (3.78 ppm) of residue E was determined according to cross-peak δ 4.01 / 3.78 ppm, H6 (3.68, 3.77 ppm) of residue E was determined according to cross-peak δ 3.78 / (3.68, 3.77) ppm. Then the chemical shifts of C1, C2, C3, C4, C5, C6 of residue E were δ 103.97, 72.41, 80.13, 68.39, 73.49, 66.77 ppm respectively by attributing the chemical shifts of C on the sugar ring through HSQC signals. Among them, the chemical shifts of C1, C3, C6 shifted to low field, indicating that the residue was substituted at the O-1, O-3, O-6 positions of the sugar ring. Combined with the results of methylation analysis and literature reports, it was inferred that the sugar residue E might be →3,6)-β-D-Galp-(1→.

[0153] Sugar residue F: the anomeric signal δ 4.98 / 107.35 ppm (H1 / C1) indicated that residue F might be an α-arabinose residue. In the COSY spectrum, H2 (4.01 ppm) of residue F was determined according to the cross-peak δ 4.98 / 4.01 ppm, H3 (3.83 ppm) of residue F was determined according to the cross-peak δ 4.01 / 3.83 ppm, H4 (4.02 ppm) of residue F was determined according to the cross-peak δ 3.83 / 4.02 ppm, and H5 (3.61 ppm) of residue F was determined according to the cross-peak δ 4.02 / 3.61 ppm. Then the chemical shifts of C on the sugar ring were assigned by HSQC signals, the chemical shift of C1 of residue F was δ 107.35 ppm, the chemical shift of C2 of residue F was δ 80.99 ppm, the chemical shift of C3 of residue F was δ 76.49 ppm, the chemical shift of C4 of residue F was δ 83.72 ppm, and the chemical shift of C5 of residue F was δ 60.83 ppm, wherein the chemical shift of C1 shifted to low field, indicating that the residue was substituted at the O-1 position of the sugar ring, and it was inferred that the sugar residue F might be α-L-Araf-(1→ according to the methylation analysis results and literature reports.

[0154] Sugar residue G: the anomeric signal δ 5.13 / 109.1 ppm (H1 / C1) indicated that residue G might be an α-arabinose residue. In the COSY spectrum, H2 (4.1 ppm) of residue G was determined according to the cross-peak δ 5.13 / 4.1 ppm, H3 (3.89 ppm) of residue G was determined according to the cross-peak δ 4.1 / 3.89 ppm, H4 (4.19 ppm) of residue G was determined according to the cross-peak δ 3.89 / 4.19 ppm, and H5 (3.83 ppm) of residue G was determined according to the cross-peak δ 4.19 / 3.83 ppm. The chemical shifts of C on the sugar ring were assigned by HSQC signals: the chemical shift of C1 of residue G was δ 109.1 ppm, the chemical shift of C2 of residue G was δ 81.87 ppm, the chemical shift of C3 of residue G was δ 76.64 ppm, the chemical shift of C4 of residue G was δ 81.32 ppm, and the chemical shift of C5 of residue G was δ 66.1 ppm, wherein the chemical shifts of C1 and C5 shifted to low field, indicating that the residue was substituted at the O-1 and O-5 positions of the sugar ring, and it was inferred that the sugar residue G might be →5)-α-L-Araf-(1→ according to the methylation analysis results and literature reports.

[0155] Sugar residue H: anomeric signal δ 5.04 / 106.92 ppm (H1 / C1) indicated that residue H might be an α-arabinose residue. In the COSY spectrum, H2 of residue H (4.05 ppm) was determined according to the cross-peak δ 5.04 / 4.05 ppm, H3 of residue H (3.85 ppm) was determined according to the cross-peak δ 4.05 / 3.85 ppm, and H4 of residue H (3.97 ppm) was determined according to the cross-peak δ 3.85 / 3.97 ppm. The chemical shifts of C1 of residue H (δ 106.92 ppm), C2 of residue H (δ 86.9 ppm), C3 of residue H (δ 83.79 ppm), and C4 of residue H (δ 83.91 ppm) were assigned by HSQC signals. Combined with the results of methylation analysis and literature reports, it was inferred that residue H might be →2,3,5)-α-L-Araf-(1→.

[0156] The signals of the sugar residues of the sample were assigned by combining one-dimensional NMR and two-dimensional NMR spectra, as shown in Table 3.

[0157] Table 3. Sugar residues 1 H and 13 C chemical shifts

[0158] Based on the chemical shifts of the sugar residues 13 C and 1 H in the sample, the structure and linkage mode in the polysaccharide were analyzed by combining HMBC and NOESY spectra. According to the HMBC spectrum, there was a cross-peak δ 4.98 / 66.1 ppm between H1 of sugar residue F and C5 of sugar residue G, and a cross-peak δ 109.1 / 3.77 ppm between C1 of sugar residue G and H6 of sugar residue E. According to the NOESY spectrum, there was a cross-peak δ 5.14 / 4.0 ppm between H1 of sugar residue A and H2 of sugar residue A, a cross-peak δ 5.14 / 3.59 ppm between H1 of sugar residue A and H4 of sugar residue B, a cross-peak δ 5.14 / 4.31 ppm between H1 of sugar residue A and H4 of sugar residue D, a cross-peak δ 4.38 / 3.59 ppm between H1 of sugar residue B and H4 of sugar residue B, a cross-peak δ 4.38 / 3.62 ppm between H1 of sugar residue B and H3 of sugar residue E, a cross-peak δ 4.88 / 4.0 ppm between H1 of sugar residue C and H2 of sugar residue A, a cross-peak δ 4.95 / 4.29 ppm between H1 of sugar residue D and H4 of sugar residue C, a cross-peak δ 4.53 / 4.0 ppm between H1 of sugar residue E and H2 of sugar residue A, a cross-peak δ 5.13 / 3.68 ppm between H1 of sugar residue G and H6 of sugar residue E, and a cross-peak δ 5.13 / 3.77 ppm between H1 of sugar residue G and H6 of sugar residue E.

[0159] Based on the one-dimensional and two-dimensional NMR information and methylation analysis, it is inferred that the polysaccharide is mainly connected by →2)-α-L-Rhap-(1→, →4)-β-D-Galp-(1→, →4)-α-D-GalpA-(1→, →4)-α-D-GalpA-6-OMe-(1→, →3,6)-β-D-Galp-(1→, etc. to form a main chain, and the branched chain is connected by α-L-Araf-(1→5)-α-L-Araf-(1→ at the O-6 position of →3,6)-β-D-Galp-(1→, etc. Therefore, the structure of the polysaccharide chain is as follows:

[0160] Example 3: Effect of jute uniform polysaccharide CCP-D2N1 on CTX-induced immunosuppressed mice Cyclophosphamide (CTX) is a commonly used chemotherapeutic drug, but has a large side effect, and overuse can cause side effects such as leukopenia, immunosuppression and myelosuppression. Studies have shown that natural polysaccharides can restore normal immunity and CTX-induced immunosuppression. Therefore, the present application selects CTX-induced immunosuppressed mice as a model to study the immune activation of jute uniform polysaccharide CCP-D2N1 at different concentrations.

[0161] I. Experimental method (1) Animal grouping and administration 60 healthy male Kunming mice were randomly divided into a control group (NC), a model group (MC), a lentinan (LNT, 6 mg / kg) group and a jute polysaccharide low (CCP-L, 100 mg / kg), medium (CCP-M, 200 mg / kg) and high dose group (CCP-H, 400 mg / kg) after one week of adaptive feeding, 10 mice in each group. The control group and the model group were continuously administered with the same amount of normal saline, and the administration groups were administered with the corresponding drugs for 15 days. Except for the blank group, the administration groups were injected with cyclophosphamide (70 mg / (kg·d)) on the 9th, 10th and 11th days to establish the model.

[0162] (2) Effect of jute uniform polysaccharide CCP-D2N1 on body weight and immune organ index of immunosuppressed mice The mice were weighed every week. After the experiment, all mice were fasted for 10 h without water, and anesthetized by intraperitoneal injection of 1.2% tri- bromoethanol (0.2 mL / 10 g). The whole blood was drawn from the abdominal aorta. 20 μL of the blood was taken for blood cell counting, and the rest of the blood sample was centrifuged at 35000 r / min at 4°C for 10 min after standing at 4°C for 2 h. The serum was taken and stored in a refrigerator at -80°C. After blood collection, the spleen and liver tissues were quickly collected, washed with cold physiological saline, and the spleen and thymus tissues of each animal were weighed and the spleen / thymus index was calculated. Spleen / thymus = spleen (thymus) mass (mg) / body mass (g).

[0163] (3) Spleen tissue morphological analysis The mouse spleen was washed with phosphate buffered saline solution, placed in 4% paraformaldehyde solution, fixed for 24 h, dehydrated, paraffin-embedded, and sectioned. Hematoxylin-eosin staining (H&E) was performed for 5 min, dehydrated, and mounted with neutral balsam. The histopathological conditions were observed under an optical microscope, and pictures were taken.

[0164] (4) Effects of cytokine levels and enzyme activity in mouse serum The frozen serum was taken, and the contents of IL-6, IL-2, TNF-α, and IFN-γ were determined by ELISA kit; and the activities of ACP and LDH were determined according to the kit instructions.

[0165] (5) Detection of MDA, CAT, SOD, and GSH-Px activities in liver tissue The frozen liver tissue was taken, washed with ice-cold physiological saline, absorbed with filter paper, and 0.25 g of liver tissue was weighed. After dilution with physiological saline at a ratio of 1:9, ice-cold physiological saline was taken into the tube with a micro pipette, and 5% tissue homogenate was prepared with a high-speed homogenizer at a speed of about 3000 r / min. The absorbance value (OD value) at 540 nm wavelength was detected according to the instructions of the kit, the protein content in the tissue homogenate was calculated from the result value, the absorbance values of each tube were measured at wavelengths of 532 nm, 550 nm, and 412 nm, and the contents of MDA, the activities of CAT, SOD, and GSH-Px were calculated.

[0166] (6) Determination of the antioxidant stress capacity of the spleen About 50 mg of spleen tissue was taken into a 2 mL centrifuge tube, cut into pieces, and homogenized with 9 times the volume of physiological saline under ice bath conditions. The supernatant was taken after centrifugation at 2500 r / min at 4°C for 10 min, and the activities of CAT and the content of MDA were detected according to the instructions of the kit.

[0167] (7) Statistical analysis All experimental data are expressed as x̅ ± S.E.M. Statistical analysis was performed using Graphpad Prism 8.0 software. Multiple comparisons between groups were performed using the Tukey method to determine if differences were significant, P < 0.05 was considered statistically significant.

[0168] II. Experimental results (1) Effect of uniform corchorus polysaccharide CCP-D2N1 on body weight and organ index of mice Body weight, spleen and thymus index reflect the immune function of CTX-induced immunosuppressed mice. As shown in Figure 17 compared with the control group, the body weight, spleen weight, thymus weight and spleen and thymus index of the CTX treatment group were significantly reduced, indicating that the injection of CTX successfully constructed the immunosuppression model. After the treatment of uniform corchorus polysaccharide (CCP-D2N1), the body weight of mice was normalized, and the spleen and thymus index was improved, indicating that CCP-D2N1 can reverse the atrophy of immune organs induced by CTX. In order to further analyze the damage degree of immune organs, the present application evaluates the morphological changes of spleen tissue by hematoxylin-eosin (H&E) staining. As shown in Figure 18 , CTX makes the boundary between red pulp and white pulp of spleen tissue blurred, the number and size of spleen nodules are significantly reduced, and the lymph tissue cells around the spleen nodules become sparse. While after the treatment of uniform corchorus polysaccharide (CCP-D2N1), the red and white pulp in the spleen shows clear boundary, the number of spleen nodules increases significantly, and the lymphocytes become more dense, indicating that CCP-D2N1 significantly reduces the weight loss and immune organ damage induced by CTX.

[0169] (2) Effect of uniform corchorus polysaccharide CCP-D2N1 on immune cytokines in the spleen of mice CTX can cause oxidative stress in the body, produce excessive lipid peroxides (such as MDA), and reduce the levels of CAT, T-SOD and GSH-Px, thereby causing cell damage. Therefore, the present application determines the content of immune cytokines in the spleen of mice in different groups to evaluate the immune regulation effect of uniform corchorus polysaccharide CCP-D2N1. As shown in Figure 19 , compared with the control group, after CTX modeling, the MDA level in the spleen tissue of mice increased by 113.5%, and the contents of CAT, T-SOD and GSH-Px decreased by 75.8%, 36.3% and 52.6%, respectively; after the treatment of CCP-D2N1, the MDA level decreased by more than 14.7%, and the contents of CAT, T-SOD and GSH-Px increased by more than 197.6%, 21.9% and 34.9%, respectively, indicating that uniform corchorus polysaccharide CCP-D2N1 can improve the oxidative stress caused by CTX and thus play an immune activation role.

[0170] (3) Effect of uniform corchorus polysaccharide CCP-D2N1 on blood cell count in mice The number of immune cells in blood plays a crucial role in immune response. CTX can reduce the number of leukocytes in blood and inhibit hematopoiesis in the marrow and extramedullary. The present application evaluates the immune activation effect of uniform corchorus polysaccharide CCP-D2N1 by determining the number of leukocytes, erythrocytes, monocytes, neutrophils and lymphocytes in blood of different groups. As shown in Table 2, compared with the control group, the number of leukocytes, erythrocytes, monocytes, neutrophils and lymphocytes in blood of mice after CTX administration decreased by 47.0%, 26.1%, 57.3%, 45.6% and 48.1% (P<0.001), respectively. After administration of uniform corchorus polysaccharide CCP-D2N1, the number of leukocytes, erythrocytes, monocytes, neutrophils and lymphocytes in blood of immunosuppressed mice increased by more than 33.7%, 10.3%, 50.4%, 13.8% and 14.2%, respectively. Notably, after administration of high-dose CCP-D2N1 (400 mg / kg / d), all blood cells in blood of immunosuppressed mice were restored, indicating that CCP-D2N1 can restore abnormal blood cell count induced by CTX. Figure 20

[0171] (4) Effect of uniform corchorus polysaccharide CCP-D2N1 on cytokines in serum of mice TNF-α, IL-2, IL-6 and IFN-γ secreted by macrophages and other immune cells play a crucial role in immune regulation in vivo, therefore the present application evaluates the secretion of cytokines in serum using ELISA assay. As shown in Table 3, the level of IL-2, IL-6, TNF-α and IFN-γ in serum of mice in CTX group decreased by 39.8%, 72.5%, 63.9% and 66.5% (P<0.001), respectively. Treatment with CCP-D2N1 increased the level of IL-2, IL-6, TNF-α and IFN-γ by more than 30.5%, 154.0%, 105.3% and 24.1%, respectively, indicating that CCP-D2N1 has the ability to increase cytokine production in CTX-induced immunosuppression. Figure 21

[0172] (5) Effect of uniform corchorus polysaccharide CCP-D2N1 on TLR4 / NF-κB / MAPK signaling pathway ​​Toll-like receptors (TLRs) are essential pattern recognition molecules in innate immunity, and their downstream signaling cascades, nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinase (MAPK) pathways, are crucial for initiating innate immune responses and enhancing the defense mechanisms of the immune system. MAPK is responsible for transmitting signals from external stimuli to the nucleus and consists of three major subfamilies, including extracellular signal-regulated kinase (ERK), c-Jun N-terminal kinase (JNK), and p38. NF-κB is a key transcriptional regulator in immune and inflammatory responses. The present application explores the effects of uniform polysaccharides CCP-D2N1 from Corchorus capsuarius on the TLR4 / NF-κB / MAPK signaling pathway through immunoblotting analysis. As shown in Figure 22 As shown in FIG. 2, compared with normal mice, CTX inhibited the expression of TLR4, p-NF-κB, p-ERK, p-JNK, and p-p38 proteins in the spleen tissue of mice (P<0.001), while uniform polysaccharides CCP-D2N1 from Corchorus capsuarius could increase the expression of the above protein kinases, indicating that CCP-D2N1 might activate the immune process through the TLR4 / NF-κB / MAPK signaling pathway.

[0173] Verification of technical effects and / or analysis of technical problems In summary, uniform polysaccharides CCP-D2N1 from Corchorus capsuarius can increase the immune organ index of CTX-induced immunosuppressed model mice, restore the number of blood cells, promote the production of immune and inflammatory cytokines, and restore the immune function of mice. Mechanism studies have shown that CCP-D2N1 may enhance immune function in vivo through the TLR4-mediated MAPK and NF-κB signaling pathways.

[0174] Finally, it should be noted that the above content is only used to illustrate the technical solutions of the present application, and is not a limitation on the protection scope of the present application. Simple modifications or equivalent replacements of the technical solutions of the present application made by those skilled in the art do not deviate from the essence and scope of the technical solutions of the present application.

Claims

1. A uniform polysaccharide of Corchorus capsu- laris having immunopotentiation efficacy, characterized in that, The jute uniform polysaccharide is connected by 3-4 parts of rhamnose, 0.5-2 parts of arabinose, 1-3 parts of galactose and 1-2 parts of galacturonic acid through glycosidic bond in molar fraction.

2. The uniform polysaccharide of Corchorus capsularis according to claim 1, characterized in that, The rhamnose is at least one of alpha-L-rhamnose furanose, beta-L-rhamnose furanose, alpha-D-rhamnose furanose, beta-D-rhamnose furanose, alpha-L-rhamnose pyranose, beta-L-rhamnose pyranose, alpha-D-rhamnose pyranose, beta-D-rhamnose pyranose; preferably at least one of alpha-L-rhamnose pyranose, beta-L-rhamnose pyranose, alpha-D-rhamnose pyranose, beta-D-rhamnose pyranose; further preferably at least one of alpha-L-rhamnose pyranose, beta-L-rhamnose pyranose; most preferably alpha-L-rhamnose pyranose; The arabinose is at least one of alpha-L-arabinose furanose, beta-L-arabinose furanose, alpha-D-arabinose furanose, beta-D-arabinose furanose, alpha-L-arabinose pyranose, beta-L-arabinose pyranose, alpha-D-arabinose pyranose, beta-D-arabinose pyranose; preferably at least one of alpha-L-arabinose furanose, beta-L-arabinose furanose, alpha-D-arabinose furanose, beta-D-arabinose furanose; further preferably at least one of alpha-L-arabinose furanose, beta-L-arabinose furanose; most preferably alpha-L-arabinose furanose; The galactose is at least one of alpha-L-galactose furanose, beta-L-galactose furanose, alpha-D-galactose furanose, beta-D-galactose furanose, alpha-L-galactose pyranose, beta-L-galactose pyranose, alpha-D-galactose pyranose, beta-D-galactose pyranose; preferably at least one of alpha-L-galactose pyranose, beta-L-galactose pyranose, alpha-D-galactose pyranose, beta-D-galactose pyranose; further preferably at least one of beta-L-galactose pyranose, beta-D-galactose pyranose; most preferably beta-D-galactose pyranose; The galacturonic acid is at least one of alpha-L-galacturonic acid furanose, beta-L-galacturonic acid furanose, alpha-D-galacturonic acid furanose, beta-D-galacturonic acid furanose, alpha-L-galacturonic acid pyranose, beta-L-galacturonic acid pyranose, alpha-D-galacturonic acid pyranose, beta-D-galacturonic acid pyranose; preferably at least one of alpha-L-galacturonic acid pyranose, beta-L-galacturonic acid pyranose, alpha-D-galacturonic acid pyranose, beta-D-galacturonic acid pyranose; further preferably at least one of alpha-D-galacturonic acid pyranose, beta-D-galacturonic acid pyranose; most preferably alpha-D-galacturonic acid pyranose; Preferably, the molar fraction among the components is 3.5 parts of alpha-L-rhamnose, 1 part of alpha-L-arabinose, 1.9 parts of beta-D-galactose and 1.4 parts of alpha-D-galacturonic acid.

3. The uniform polysaccharide of Corchorus capsularis according to any one of claims 1 or 2, characterized in that, The structure of the uniform polysaccharide of jute is shown in the following formula I: Formula I The number of repeating units m in the structure is in the range of 2-6; preferably 3; The number of repeating units n in the structure is in the range of 2-6; preferably 3.

4. A process for the preparation of the homogeneous polysaccharide of Corchorus capsu- laris according to any one of claims 1 to 3, characterized in that, The preparation method of the uniform polysaccharide of jute comprises the following steps: ion exchange purification and gel filtration chromatography purification of jute crude polysaccharide to obtain the uniform polysaccharide of jute.

5. The preparation method according to claim 4, characterized in that, The ion exchange purification comprises the following steps: dissolving the jute crude polysaccharide in a solvent to obtain a jute crude polysaccharide mother liquor; passing through an ion exchange column, collecting the eluate, and purifying to obtain a jute polysaccharide component; The solvent is at least one of water, Tris-HCl buffer, phosphate buffer, and sodium chloride solution; preferably at least one of water and sodium chloride solution; further preferably water; The concentration of the jute crude polysaccharide mother liquor is 10-30 mg / mL; preferably 20 mg / mL; Preferably, the step of removing impurities from the jute crude polysaccharide mother liquor before passing through the ion exchange column is further included. The impurity removal method of the jute crude polysaccharide mother liquor is centrifugation to obtain the supernatant; preferably, the impurity removal method of the jute crude polysaccharide mother liquor is centrifugation at a speed of 5000-20000 r / min for 5-30 min; further preferably, centrifugation at a speed of 10000 r / min for 10 min; The ion exchange column is at least one of a Cellulose DEAE-cellulose column, an aminoethyl cellulose column, a Q Sepharose gel column, and a SP Sepharose gel column; preferably any one of Cellulose DEAE-52, Cellulose DEAE-22, Cellulose DEAE-23, Cellulose DEAE-32, and Cellulose DEAE-11; further preferably Cellulose DEAE-52; The flow rate of the ion exchange column is 2-6 mL / min; preferably 4 mL / min; The elution conditions are gradient elution with pure water, 0.05-0.15 M, 0.15-0.25 M, and 0.25-0.35 M NaCl solutions in sequence; preferably gradient elution with pure water, 0.1 M, 0.2 M, and 0.3 M NaCl solutions in sequence; further preferably elution with 0.1 M NaCl solution, and the collected eluate is marked as D2; Preferably, the purification includes concentration and dialysis; The concentration is concentrated to 1 / 4-1 / 6 of the original volume; further preferably, the concentration is concentrated to 1 / 5 of the original volume; The dialysis is dialysis for 30-60 h with a dialysis bag with a molecular weight cut-off of 3000 Da; further preferably, the dialysis is dialysis for 48 h with a dialysis bag with a molecular weight cut-off of 3000 Da; Preferably, the purification further comprises drying; further preferably, the drying method is freeze-drying.

6. The preparation method according to claim 4, characterized in that, The gel filtration chromatography purification comprises the following steps: adding a solvent to the purified product obtained after ion purification, marked as CCP-D2, to prepare a CCP-D2 mother liquor, passing through a gel chromatography column for separation and purification, collecting the eluate, and purifying to obtain the uniform polysaccharide of jute. The solvent is at least one of water, a phosphate buffer, a NaCl solution, a Tris-HCl buffer; preferably water, a NaCl solution; further preferably water; The concentration of the jute polysaccharide component mother liquor is 1-10 mg / mL; preferably 2 mg / mL; Preferably, before the over-gel chromatography column, the method further comprises a step of removing impurities from the jute crude polysaccharide mother liquor; Further preferably, the impurity removal is centrifugation at a speed of 5000-20000 r / min for 5-30 min; further preferably, centrifugation at a speed of 10000 r / min for 10 min; The type of the gel chromatography column is at least one of a cross-linked dextran gel Sephadex series, an agarose gel Sepharose / Superose series, a polyacrylamide gel Bio-Gel P series, and a composite gel; preferably at least one of Sephadex G-75, Sephadex G-100, Superose 12, and Superdex 200 10 / 300 GL; further preferably Superdex 200 10 / 300 GL; The flow rate of the over-gel chromatography column is 0.5-2 mL / min; preferably 1 mL / min; The elution condition is gradient elution with pure water, 0.05-0.15 M, 0.15-0.25 M, and 0.25-0.35 M NaCl solutions in sequence; preferably gradient elution with pure water, 0.1 M, 0.2 M, and 0.3 M NaCl solutions in sequence; further preferably elution with pure water, and the collected gel eluate is denoted as CCP-D2N1; Preferably, the elution volume ranges from 1.0 to 2.0 times the column volume; further preferably 1.5 times the column volume; Preferably, the purification process comprises concentration and drying; The concentration is to 1 / 4-1 / 6 of the original volume; further preferably to 1 / 5 of the original volume; Preferably, the drying method is freeze-drying.

7. The method of making according to any one of claims 4 or 5, wherein, The method for preparing the jute crude polysaccharide comprises the following steps: (1) reflux extraction of jute leaves with a solvent, alcohol precipitation treatment of the extract, and obtaining a jute crude product; (2) enzymatic hydrolysis of the jute crude product obtained in step (1), extraction, and purification treatment, and obtaining a jute crude polysaccharide; In step (1), the solvent is at least one of water, 0.1-1 M HCl solution, 0.1-1 M NaOH solution, and NaCl solution; preferably at least one of water, 0.1-1 M HCl solution, and 0.1-1 M NaOH solution; further preferably water; most preferably, the temperature of water is 60-100℃; In step (1), the solid-liquid ratio of jute leaves to solvent is 1:5-1:30; preferably 1:8; In step (1), the number of reflux extraction is 1-3 times; preferably 2 times; In step (1), the extraction time of each reflux extraction is 1-3 h; preferably 2 h; In step (1), the alcohol content of the alcohol precipitation treatment solution is 80%-90%; preferably 80%.

8. The preparation method according to claim 7, characterized in that, In step (2), before enzymatic hydrolysis, the method further comprises a step of dissolving the jute crude product in a solvent; The solvent is water or NaCl solution; preferably water; The ratio of the jute crude polysaccharide to the solvent is 1:50-1:120; preferably 1:100; The enzyme used in the enzymolysis in step (2) is at least one of papain, proteinase K, trypsin and pronase; preferably papain; The concentration of the enzyme used in the enzymolysis in step (2) is 0.1-2.0%; preferably, the concentration of the enzyme used in the enzymolysis is 0.1-1%, 0.5-1.5%, 0.5-1%; further preferably 1.5%. Preferably, the purification treatment in step (2) comprises adsorption and dialysis; Further preferably, the adsorption is by AB-8 macroporous resin; Further preferably, the dialysis is by dialysis bag with a molecular weight cut-off of 3000 Da for 24-72 h; further preferably, the dialysis is by dialysis bag with a molecular weight cut-off of 3000 Da for 48 h; Preferably, the purification treatment in step (2) further comprises drying; further preferably, the drying is by freeze-drying.

9. The uniform polysaccharide of Corchorus capsularis according to any one of claims 1 to 3, characterized in that, Use of the jute uniform polysaccharide in the preparation of an immunomodulatory drug.

10. An immunomodulatory pharmaceutical composition, characterized in that, The active ingredient thereof comprises the jute uniform polysaccharide according to any one of claims 1-3, and one or more pharmaceutically acceptable carriers, diluents, excipients.

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