Brassica rapa polysaccharide as well as extraction method and application thereof

Abstract

The invention provides brassica rapa polysaccharide as well as an extraction method and application thereof. The structure of the Brassica rapa polysaccharide is as follows: # imgabs0 #, and the Brassica rapa polysaccharide has excellent oxidation resistance, so that a new thought is provided for application of the Brassica rapa polysaccharide in development and research of antioxidant drugs.

Description

Technical Field

[0001] The present invention relates to the technical field of drug development and functional food, and in particular to chamacarp polysaccharide and an extraction method and application thereof. Background Art

[0002] As people's health awareness increases, medicinal and edible plants that can regulate the body's sub-health state are developing rapidly at home and abroad, not only enriching traditional food resources, but also their functional factors or characteristic ingredients are often used as raw materials in the development of functional foods and special medical formula foods. In the current era of high incidence of chronic diseases and rising lifestyle diseases, medicinal and edible plants are particularly important.

[0003] Chamagu, scientifically known as Brassica rapa L., is a biennial herbaceous plant of the genus Brassica in the family Cruciferae. The fleshy root of Chamagu is the main edible and medicinal part. It is rich in nutrition and has a unique flavor. It is rich in various amino acids, proteins, polysaccharides, glucosinolates and other active substances. It has multiple physiological activities such as enhancing immunity, relieving cough and asthma, anti-tumor, anti-oxidation, and anti-radiation.

[0004] Free radicals are considered to be the pathogens of various acute and chronic pathologies. The antioxidant defense system plays an important role in scavenging free radicals and preventing cell damage. Therefore, it is of great significance to enhance the antioxidant defense system. At present, antioxidants are mainly divided into two categories: natural and synthetic. Among them, natural antioxidants have lower toxicity and side effects, so it is of great significance to develop new, non-toxic antioxidants. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the prior art at least to a certain extent. To this end, one object of the present invention is to provide a chamagu polysaccharide and an extraction method and application thereof.

[0006] In the first aspect of the present invention, the present invention provides a chamagu polysaccharide. According to an embodiment of the present invention, the structure of the chamagu polysaccharide is as follows: .

[0007] According to the chamagu polysaccharide of the above embodiment of the present invention, the in vitro antioxidant experiment shows that the chamagu polysaccharide of the present application has excellent antioxidant capacity, which provides a new idea for the research and development of the application of chamagu polysaccharide in antioxidant drugs, and opens up new ideas for the research and development of new chamagu extracts in food, health products and antioxidant drugs.

[0008] In some embodiments of the present invention, the molecular weight of the chamagu polysaccharide is 57.6 KD.

[0009] In some embodiments of the present invention, the molar ratio of each monosaccharide in the chamagu polysaccharide is: fucose: arabinose: galactose: glucose: xylose: galacturonic acid = 0.1: 3.06: 1.14: 94.29: 1.30: 0.10.

[0010] In a second aspect of the present invention, the present invention provides a method for extracting the above-mentioned chamagu polysaccharide. According to an embodiment of the present invention, the method comprises: (1) crushing the chamagu, and then defatting, ultrasonic extraction, decolorization, protein removal, and dialysis in sequence to obtain chamagu crude polysaccharide; (2) The crude chamagu polysaccharide is purified by a DEAE-52 cellulose anion exchange column and a Sephadex G-100 gel chromatography column in sequence to obtain chamagu polysaccharide.

[0011] According to the above-mentioned method for extracting chamagu polysaccharides of the present invention, chamagu polysaccharides with excellent antioxidant properties of the present application can be prepared. This method has the advantages of simple operation, low cost, high efficiency, etc. The obtained chamagu polysaccharides have high purity and strong activity, which provides a new idea for the development and research of chamagu polysaccharides in antioxidant drugs.

[0012] In some embodiments of the present invention, in step (1), the defatting comprises: crushing the chamagu and then soaking it in anhydrous ethanol.

[0013] As an example, fresh chamagu was crushed, and then 10 times the amount of 80% anhydrous ethanol was added, soaked for 0.5 h, stirred in a magnetic stirrer at 60 ° C for 2 h, repeated the operation twice, filtered, and dried at 50 ° C to obtain chamagu defatted powder.

[0014] In some embodiments of the present invention, in step (1), the ultrasonic extraction comprises: dissolving the defatted chamagu powder in ultrapure water and subjecting the solution to ultrasonic treatment to obtain an extract, adding anhydrous ethanol to the extract, standing the extract for centrifugation, and collecting the precipitate.

[0015] As an example, the above-mentioned Chamagu powder is dissolved in ultrapure water, and the concentration of Chamagu powder is 1 / 30 g / mL.

[0016] In some embodiments of the present invention, in step (1), during the ultrasonic extraction, the ultrasonic power is 180W-220W, the extraction temperature is 58°C-62°C, and the extraction time is 2.5h-3.5h.

[0017] In some embodiments of the present invention, in step (1), during the ultrasonic extraction, the extract is concentrated to 0.2 to 0.3 times of the original volume, anhydrous ethanol is added until the ethanol concentration of the mixed system is 78% to 82%, and the mixture is allowed to stand at 3°C ​​to 5°C for 20h to 30h.

[0018] As an example, the extract was concentrated under reduced pressure at 60° C. to 1 / 4 of the original volume, anhydrous ethanol was added until the ethanol concentration of the system was 80%, precipitation was carried out at 4° C. overnight, and the precipitate was collected by centrifugation.

[0019] In some embodiments of the present invention, in step (1), the decolorization comprises: dissolving the precipitate obtained by ultrasonic extraction in ultrapure water and removing the pigment by adsorption using AB-8 macroporous resin.

[0020] In some embodiments of the present invention, during the decolorization, AB-8 macroporous resin is added to the aqueous solution in which the precipitate is dissolved, and the concentration of the AB-8 macroporous resin is 0.08-0.1 g / mL.

[0021] In some embodiments of the present invention, in step (1), the protein removal comprises: adding 1 / 3 to 1 / 5 times the volume of sevage reagent to the decolorized solution for extraction to obtain a supernatant, and removing the organic reagent by rotary evaporation, wherein the sevage reagent is composed of chloroform and n-butanol in a volume ratio of 4:1.

[0022] In some embodiments of the present invention, in step (1), the dialysis comprises: placing the supernatant obtained after protein removal in a dialysis bag with a molecular weight cut-off of 10,000 Da, and dialyzing for 65 h to 80 h. Furthermore, the dialysis is performed at room temperature.

[0023] In some embodiments of the present invention, in step (1), after dialysis, the solution in the dialysis bag is taken out, concentrated by rotary evaporation, and then vacuum freeze-dried for 48 hours to obtain the crude chamagu polysaccharide.

[0024] In some embodiments of the present invention, in step (2), the eluents used in the purification treatment of the DEAE-52 cellulose anion exchange column are 0 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, and 0.5 mol / L sodium chloride solutions, respectively, and the volumes of the sodium chloride solutions of different concentrations are independently 1.5 to 2 L. Furthermore, the elution rate of the eluent is 4 ml / min to 6 ml / min.

[0025] In some embodiments of the present invention, before the chamagu crude polysaccharide is purified by the DEAE-52 cellulose anion exchange column, the chamagu crude polysaccharide is dissolved in ultrapure water and filtered through a 0.45µm filter membrane after centrifugation. Thereby, excess impurities are removed as much as possible to obtain a higher purity chamagu crude polysaccharide. The chamagu polysaccharide of the present application can be purified by the above-mentioned DEAE-52 cellulose anion exchange column purification process.

[0026] As an example, 3 g of chamagu polysaccharide was dissolved in an appropriate amount of ultrapure water, centrifuged at 10,000 rpm / min for 5 min, filtered through a 0.45 µm filter membrane, and purified using a DEAE-52 cellulose anion exchange column (5 × 100 cm). The eluent was 0, 0.1, 0.2, 0.3, 0.4, and 0.5 M sodium chloride solution, and the elution rate was 5 mL / min. Equal amounts were collected (50 mL / tube), and the polysaccharide content was detected by the phenol-sulfuric acid method. The eluate was collected, then concentrated, and vacuum-freeze-dried, and the ultrapure water elution fraction was collected for further separation and purification.

[0027] In some embodiments of the present invention, in step (2), the eluent used in the Sephadex G-100 gel chromatography column purification is ultrapure water. Furthermore, the elution rate of the eluent is 0.8 ml / min to 1.2 ml / min. The chamagu polysaccharide of the present application can be purified by using the above-mentioned Sephadex G-100 gel chromatography column purification process.

[0028] In some embodiments of the present invention, before purification by Sephadex G-100 gel chromatography column, the sample purified by DEAE-52 cellulose anion exchange column is centrifuged and filtered through a 0.45µm filter membrane, thereby removing excess impurities as much as possible and obtaining a higher purity of chamagu crude polysaccharide.

[0029] As an example, the polysaccharide component purified by DEAE-52 cellulose anion exchange column with a concentration of 15 mg / mL was centrifuged at 10,000 rpm / min for 5 minutes, the supernatant was filtered through a 0.45 µm filter membrane, and purified by a Sephadex G-100 gel chromatography column (2.6×50 cm). The eluent was ultrapure water at an elution rate of 1 mL / min. Equal amounts were collected (8 mL / tube), and the polysaccharide content was detected by the phenol-sulfuric acid method. The eluate was collected, concentrated, and vacuum-freeze-dried to obtain Chamaglucoside polysaccharide.

[0030] In the third aspect of the present invention, the present invention proposes the use of the above-mentioned Chamagu polysaccharide or the Chamagu polysaccharide extracted by the above-mentioned method in the fields of medicine, food, health care products or cosmetics.

[0031] The present invention has at least the following technical effects: (1) The in vitro antioxidant experiment shows that the chamagu polysaccharide of the present invention has excellent antioxidant capacity, which provides a new idea for the development and research of the application of chamagu polysaccharide in antioxidant drugs, and opens up a new idea for the research and development of chamagu polysaccharide in food, health products and new antioxidant drugs.

[0032] (2) The method for extracting chamagu polysaccharide of the present invention can prepare chamagu polysaccharide with excellent antioxidant properties. The method has the advantages of simple operation, low cost, high efficiency, etc. The obtained chamagu polysaccharide has high purity and strong activity. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 This is the elution curve of the Chamagu polysaccharide BRL of Example 1 of the present invention; Figure 2 is a high performance liquid chromatogram of the chamagu polysaccharide BRL of Example 1 of the present invention; Figure 3 is the infrared spectrum of the chamagu polysaccharide BRL of Example 1 of the present invention; Figure 4 This is a monosaccharide composition analysis diagram of the chamagu polysaccharide BRL of Example 1 of the present invention; Figure 5 This is the GC-MS total ion current diagram of the chamagu polysaccharide BRL of Example 1 of the present invention; Figure 6 This is a graph showing the DPPH clearance test results of the chamagu polysaccharide BRL of Example 1 of the present invention; Figure 7 This is a graph showing the ABTS clearance test results of the Chamagu polysaccharide BRL of Example 1 of the present invention; Figure 8 This is a graph showing the OH radical scavenging rate test results of the Chamaglucoside BRL of Example 1 of the present invention. DETAILED DESCRIPTION

[0035] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0036] Example 1

[0037] (1) Extraction of chamagu polysaccharides

[0038] Fresh chamagu was cut into 1 cm slices, freeze-dried with a freeze dryer, crushed with a pulverizer, and 80% anhydrous ethanol was added at a material-liquid ratio of 1:10. The mixture was heated and stirred at 60 °C for 2 h in a magnetic stirrer. The above operation was repeated twice. The residue was filtered and dried in an oven at 50 °C. Ultrapure water was added at a material ratio of 1:30 g / mL, and the first extraction was performed at 200 W and 60 °C for 3 h. After the extraction, the mixture was centrifuged at 10000 r / min for 15 min, the supernatant was collected, the residue was extracted again for the second time, and the supernatants of the two times were combined. Next, the combined filtrate was concentrated to 1 / 4 of the original volume using a rotary evaporator. After the solution was cooled, 4 times the volume of anhydrous ethanol was slowly added to an ethanol concentration of 80%, and it was fully stirred at the same time, and then allowed to stand overnight at 4 °C. After overnight, the precipitate was collected and re-dissolved with ultrapure water, and the activated AB-8 macroporous resin was added to the solution of the polysaccharide precipitate re-dissolved above to make the final concentration of the macroporous resin 0.1g / mL. Oscillate at room temperature for 2 hours to remove the pigment of the polysaccharide, filter the supernatant, add 1 / 4 times the volume of the supernatant sevage reagent (chloroform: n-butanol = 4:1), shake well for 15 minutes, remove the denatured protein layer after standing for a period of time, absorb the supernatant, and repeat the above steps until there is no denatured protein layer. The supernatant was evaporated to a certain volume to remove the organic reagent. Then, the polysaccharide solution was placed in a dialysis bag with a molecular weight cutoff of 10,000Da, dialyzed for three days, and the dialysis water was changed every 4 hours, and freeze-dried to obtain the crude polysaccharide of Chamagu.

[0039] (2) Purification of Chamagu polysaccharide

[0040] Weigh 500g of DEAE-52 cellulose and add 5L of ultrasonic ultrapure water to swell for 2h, several times until there is no impurity in the upper layer. The filter residue was first soaked in 0.5mol / L NaOH solution for 2h, and then washed with ultrapure water until neutral. Then continue to soak in 0.5mol / L HCl solution for 2h, and then wash with ultrapure water until neutral. Finally, soak the filter residue again in 0.5mol / L NaOH solution for 2h, and thoroughly wash with ultrapure water until neutral. When loading the column, use a funnel to slowly pour DEAE-52 cellulose into the chromatography column (5.0×100 cm), flush the column with 5 times the column volume of ultrapure water for 12h, and all eluents are ultrasonically treated. The chamagu polysaccharide was prepared into a 15mg / mL aqueous solution, centrifuged at 10000r / min for 5min, and the supernatant was filtered through a 0.45µm needle filter and loaded. The sample volume was 50 mL each time, and 0 M, 0.1 M, 0.2 M, 0.3 M, 0.4 M and 0.5 M NaCl solutions were used for gradient elution. The eluate was collected by an automatic collector at a flow rate of 5 mL / min, and equal amounts were collected (50 mL / tube). The polysaccharide content was detected by the phenol-sulfuric acid method. Each sample was loaded several times, and the corresponding tube array fraction with the highest peak of the water elution curve was collected, concentrated, dialyzed, and stored after vacuum freeze drying. The polysaccharides in the water-washed fraction were collected for further separation and purification.

[0041] Weigh 25g of Sephadex G-100 dextran gel, add 2L of ultrapure water that has been ultrasonicated to swell for three days, boil at 90℃ for 0.5h, and slowly pour into a chromatography column (2.6×50 cm) after ultrasonic treatment. Prepare 15mg / mL aqueous solution of Chamagu polysaccharide, centrifuge at 10000 r / min for 5min, and pass the supernatant through a 0.45µm needle filter. Each load is 5mL, eluted with ultrapure water, and the eluate is collected by an automatic collector at a flow rate of 1mL / min, and equal amounts are collected (8mL / tube). The polysaccharide content is detected by the phenol-sulfuric acid method. Each sample is loaded several times, the components are collected, concentrated, and stored after vacuum freeze-drying to obtain Chamagu polysaccharide BRL.

[0042] The elution curve of the Qiamagu polysaccharide BRL in Example 1 is as follows: Figure 1 shown.

[0043] Structural characterization of the chamagu polysaccharide BRL of Example 1

[0044] (1) Determination of molecular weight

[0045] High performance liquid chromatography was used, equipped with a Waters HPLC system connected in series with a size exclusion chromatography and a multi-angle laser light scattering detector and a Shodex806 column, with 0.1M sodium chloride solution as the mobile phase, column temperature of 35°C, and a flow rate of 0.5 mL / min. 10 mg of polysaccharide was weighed and dissolved in 5 mL of mobile phase, filtered through a 0.45µm water filter, and placed in an injection bottle for chromatographic analysis. Figure 2 As shown, the measurement result is a single peak with symmetrical peak shape and a molecular weight of 57.6 KD; (2) Infrared spectroscopy analysis

[0046] 1.00 mg of polysaccharide sample and 100 mg of dried anhydrous potassium bromide powder were accurately weighed in a mortar and quickly ground into a uniform powder. The powder was transferred into a mold to obtain a uniform, transparent, crack-free flake. The flake was analyzed by Fourier transform infrared spectrometer at 4000 cm -1 ~400 cm -1 60 scans within the range with a resolution of 4 cm -1 , observe the absorption characteristic peaks of the infrared spectrum to analyze the sample (such as Figure 3 As shown). At 3384.04cm -1 and 2929.28cm -1 The strong absorption peak at 1649.06cm indicates the presence of strong -OH stretching vibration and -CH2 CH stretching vibration in the polysaccharide. -1 , 1369.5cm -1 There is an absorption peak at 1081.79cm, and the stretching vibration is the asymmetric stretching vibration and symmetric stretching vibration of C=O. -1 The absorption peak near 931.76cm indicates that the chamagu polysaccharide contains pyranose rings. -1 The absorption peak at 850.93 cm -1 The absorption peak at the position is an α-type glycosidic bond, and there is no characteristic absorption peak of acidic sugar, indicating that BRL is a neutral polysaccharide, which is consistent with the monosaccharide composition test results.

[0047] (3) Monosaccharide composition analysis

[0048] Weigh 10.00 mg of polysaccharide accurately into a hydrolysis tube, add 4 mL of 4 mol / L trifluoroacetic acid, fill with nitrogen for 1 minute to expel the air in the tube, tighten the screw cap, hydrolyze at 120°C for 4 h, blow dry the hydrolyzate with nitrogen after cooling, add an appropriate amount of methanol and blow nitrogen again to remove excess trifluoroacetic acid, add ultrapure water to make up to 10 mL, dilute 20 times, filter with 0.22 µm filter membrane, and inject. Chromatographic separation conditions: CarboPacTMPA20 3×150mm column; eluent: 250 mM NaOH and 1 M NaAC; detector: pulsed amperometric detector, gold electrode; flow rate: 0.5 mL / min; injection volume: 10 µL; column temperature: 35°C; mobile phase A: water, B: 250 mM NaOH, C: 1 M NaAC, elution conditions: 0-20 min, 94% A, 6% B, 0% C; 20-20.1 min, 89% A, 6% B, 5% C; 20.1-35 min, 74% A, 6% B, 20% C; 35-35.1 min, 20% A, 80% B, 0% C; 35.1-45 min, 20% A, 80% B, 0% C; 45-45.1 min, 94% A, 6% B, 0% C; 45.1-55 min, 94% A, 6% B, 0% C. Figure 4 As shown, by comparing the peak retention time and analyzing the chromatographic peak area, it can be obtained that BRL is composed of fucose, arabinose, galactose, glucose, xylose, and galacturonic acid, and the molar percentage is 0.1: 3.06: 1.14: 94.29:1.30: 0.10, among which the glucose content accounts for the highest proportion of 94.26%.

[0049] (4) Methylation analysis

[0050] Weigh the polysaccharide sample and place it in a glass reaction bottle, add 1mL of anhydrous DMSO, quickly add NaOH, seal, dissolve under ultrasound, and then add iodomethane. React in a magnetic stirring water bath at 30℃ for 60min. Finally, add 2mL of ultrapure water to the above mixture to terminate the methylation reaction. Take the methylated polysaccharide, add 1ml of 2M trifluoroacetic acid (TFA) to hydrolyze for 90min, and evaporate to dryness on a rotary evaporator. Add 2ml of double distilled water to the residue, reduce 60mg of sodium borohydride for 8 hours, add glacial acetic acid to neutralize, rotary evaporate, dry in an oven at 101 degrees, then add 1ml of acetic anhydride to acetylate at 100℃ for 1h, and cool. Then add 3mL of toluene, concentrate and evaporate to dryness under reduced pressure, and repeat 4-5 times to remove excess acetic anhydride. Dissolve the acetylated product with 3mL of CH2Cl2 and transfer it to a separatory funnel. Add a small amount of distilled water and shake it thoroughly, then remove the upper aqueous solution, and repeat this 4 times. The CH2Cl2 layer was dried with an appropriate amount of anhydrous sodium sulfate, concentrated to 1 mL, and placed in a liquid phase vial. The acetylation product samples were analyzed using a Thermo scientific, 1300-7000 gas chromatograph-mass spectrometer. GC-MS conditions: HP-INNOWAX column 30m×0.32mm×0.25um; program temperature conditions: starting temperature 140°C, heating to 230°C at 1°C / min; injection port temperature 250°C, detector temperature 250°C, carrier gas helium, flow rate 1mL / min. The GC-MS total ion chromatogram of the methylated sugar alcohol acetyl ester obtained (such as Figure 5 Six alditol acetates were detected by GC-MS, and six corresponding glycosidic bonds were identified, namely 1-Araf, 1-Glcp, 1,5-Araf, 1,4-Glcp, 1,3,4-Glcp, and 1,4,6-Glcp.

[0051] (5) Nuclear magnetic resonance spectroscopy analysis

[0052] The polysaccharide was completely dissolved in 500 µL D2O. 1H NMR, 13C NMR, COSY, HSQC, and HMBC spectra were scanned using a Bruker spectrometer (700 MHz). Based on the monosaccharide composition, methylation determination results, and NMR analysis results of BRL, it was shown that the structure of BRL mainly included →4)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, α-D-Glcp(1→, α-L-Araf(1→, →5)-α-L-Araf(1→, →3,4)-β-D-Glcp-(1→ and →4)-β-D-Glcp-(1→.

[0053] (6) Biological activity of chamagu polysaccharide

[0054] DPPH scavenging rate: Prepare a series of test solutions (0.25, 0.50, 1, 2, 3, 4 and 5 mg / mL polysaccharide solutions) and 0.40 mmol / L DPPH-ethanol solution. Use a pipette to measure 1.0 mL of DPPH-ethanol solution and 1.0 mL of test solution in centrifuge tubes, shake and react in the dark for 30 min, and measure the absorbance at 517 nm. DPPH scavenging rate results are shown in Figure 6 ,from Figure 6 It can be seen that the Chamaglucoside polysaccharide of the present application has good DPPH scavenging function, and as the concentration increases, the clearance rate increases.

[0055] ABTS clearance rate: Prepare a series of test solutions (0.25, 0.50, 1, 2, 3, 4 and 5 mg / mL polysaccharide solutions), use a pipette to measure 7.0 mmol / L ABTS solution and 2.45 mmol / L potassium persulfate solution in a 1:1 ratio, place at room temperature away from light, dilute with PBS to an absorbance of 0.7, add 1 mL polysaccharide solution and 4.0 mL ABTS working solution to a centrifuge tube, react for 10 min, and measure the absorbance at 734 nm. ABTS clearance rate results are shown in Figure 7 ,from Figure 7 It can be seen that the Chamaglucoside polysaccharide of the present application has a good ABTS clearance function, and as the concentration increases, the clearance rate increases.

[0056] OH radical scavenging rate: Prepare a series of test solutions (0.25, 0.50, 1, 2, 3, 4 and 5 mg / mL polysaccharide solutions), 7.5 mmol / LFeSO4 solution, 6mmol / L salicylic acid-ethanol solution and 0.1% H2O2 solution. Use a pipette to measure 1.5 mL of the test solution, 1.0 mL of FeSO4 solution, 1.5 mL of salicylic acid-ethanol solution and 1.0 mL of H2O2 solution into centrifuge tubes, shake and incubate at 37ºC for 1 hour, and measure the absorbance at 510 nm. The results of OH radical scavenging rate are shown in Figure 8 ,from Figure 8 It can be seen that the chamagu polysaccharide of the present application has a good OH free radical scavenging function, and the scavenging rate increases with the increase of concentration.

[0057] In addition, the biological activity of Chamagu polysaccharide is closely related to its inherent properties, including monosaccharide composition, molecular weight, type of glycosidic bond, main chain structure, etc. The present invention provides a new structure BRL, which not only contains →4)-D-Glcp-(1→ and →4,6)-α-D-Glcp-(1→ but also contains →5)-α-L-Araf(1→. After determining the antioxidant activity of Chamagu polysaccharide, the present invention analyzes its structure, which opens up a new way for the development and application of Chamagu.

[0058] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A chamagu polysaccharide, characterized in that: The structure of the chamagu polysaccharide is shown below: 。 2. The chamagu polysaccharide according to claim 1, characterized in that The molecular weight of the chamagu polysaccharide is 57.6KD.

3. The chamagu polysaccharide according to claim 1 or 2, characterized in that The molar ratio of each monosaccharide in the chamagu polysaccharide is: fucose: arabinose: galactose: glucose: xylose: galacturonic acid = 0.1: 3.06: 1.14: 94.29: 1.30: 0.

10.

4. A method for extracting chamagu polysaccharide according to any one of claims 1 to 3, characterized in that: include: (1) crushing the chamagu, and then defatting, ultrasonic extraction, decolorization, protein removal, and dialysis in sequence to obtain chamagu crude polysaccharide; (2) The crude chamagu polysaccharide is purified by a DEAE-52 cellulose anion exchange column and a Sephadex G-100 gel chromatography column in sequence to obtain chamagu polysaccharide.

5. The method according to claim 4, characterized in that: In step (1), the degreasing comprises: crushing the chamagu and soaking it in anhydrous ethanol; And / or, the ultrasonic extraction comprises: dissolving the defatted chamagu powder in ultrapure water and subjecting it to ultrasonic treatment to obtain an extract, adding anhydrous ethanol to the extract, standing and centrifuging, and collecting the precipitate; And / or, the decolorization comprises: dissolving the precipitate obtained by the ultrasonic extraction in ultrapure water and removing the pigment by adsorption with AB-8 macroporous resin; And / or, the protein removal comprises: adding 1 / 3 to 1 / 5 times the volume of sevage reagent to the decolorized solution for extraction to obtain a supernatant, and removing the organic reagent by rotary evaporation, wherein the sevage reagent is composed of chloroform and n-butanol in a volume ratio of 4:1; And / or, the dialysis comprises: placing the supernatant obtained after protein removal in a dialysis bag with a molecular weight cut-off of 10,000 Da, and dialyzing for 65 h to 80 h.

6. The method according to claim 5, characterized in that: In the ultrasonic extraction, the ultrasonic power is 180W~220W, the extraction temperature is 58℃~62℃, and the extraction time is 2.5h~3.5h; And / or, in the ultrasonic extraction, after the extract is concentrated to 0.2-0.3 times of the original volume, anhydrous ethanol is added until the ethanol concentration of the mixed system is 78%-82%, and the mixture is allowed to stand at 3°C-5°C for 20h-30h; And / or, during the decolorization, AB-8 macroporous resin is added to the aqueous solution in which the precipitate is dissolved, and the concentration of the AB-8 macroporous resin is 0.08-0.1 g / mL.

7. The method according to claim 4, characterized in that: In step (2), the eluents used in the purification treatment of the DEAE-52 cellulose anion exchange column are 0 mol / L, 0.1 mol / L, 0.2 mol / L, 0.3 mol / L, 0.4 mol / L, and 0.5 mol / L sodium chloride solutions, respectively, and the volumes of the sodium chloride solutions of different concentrations are independently 1.5 to 2 L; And / or, the elution rate of the eluent is 4 ml / min~6 ml / min.

8. The method according to claim 4, characterized in that: In step (2), the eluent used for the Sephadex G-100 gel chromatography column purification is ultrapure water; And / or, the elution rate of the eluent is 0.8 ml / min~1.2 ml / min.

9. The method according to claim 4, characterized in that: Before the crude chamagu polysaccharide is purified by the DEAE-52 cellulose anion exchange column, the crude chamagu polysaccharide is dissolved in ultrapure water, and then centrifuged and filtered through a 0.45 μm filter membrane; And / or, before purification by Sephadex G-100 gel chromatography column, the sample purified by DEAE-52 cellulose anion exchange column is centrifuged and then filtered through a 0.45 µm filter membrane.

10. Use of the chamagu polysaccharide described in any one of claims 1 to 3 or the chamagu polysaccharide extracted by the method described in any one of claims 4 to 9 in the fields of medicine, food, health care products or cosmetics.

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