A uniform polysaccharide from Portulaca oleracea L., preparation method thereof and application thereof

Abstract

The present invention relates to the technical fields of cosmetics, food and pharmaceuticals, and provides a homogeneous polysaccharide from Portulaca oleracea, a preparation method thereof and applications thereof. The homogeneous polysaccharide from Portulaca oleracea has the structural formula shown in Figure 7. Its peak molecular weight Mp, weight-average molecular weight Mw and number-average molecular weight Mn are 6.4 kDa, 7.4 kDa and 5.3 kDa respectively; the monosaccharide components are glucose, galactose and arabinose, and the proportions are 21.54%, 62.98% and 13.21% respectively. The present invention is obtained by water extraction, alcohol precipitation, ion exchange column chromatography and gel filtration column chromatography from Portulaca oleracea. Through cell experiments and animal experiments, it is determined that it has the effects of promoting the scratch healing of Hacat cells and improving the skin barrier, and can be applied in cosmetics, food and pharmaceuticals.

Description

Technical Field

[0001] The present invention relates to the technical field of cosmetics, foods and medicines, and in particular to a purslane uniform polysaccharide, a preparation method and an application thereof. Background Art

[0002] purslane( Portulaca oleracea Portulaca oleracea L., also known as Purslane, is an annual succulent herb in the Portulacaceae family. It is widely used in folk medicine for its anti-inflammatory, soothing, antibacterial, antiviral, lipid-regulating, anti-tumor, and blood sugar-lowering properties. Its active ingredients are primarily polysaccharides, organic acids, and alkaloids.

[0003] Polysaccharides are a class of complex carbohydrates widely distributed in nature. They play crucial physiological roles, such as participating in immune regulation, intercellular recognition, intercellular transport, and disease diagnosis and treatment. They also regulate cell growth and aging, and control cell division and differentiation, playing a wide range of roles in cosmetics, food, and pharmaceuticals. Summary of the Invention

[0004] In response to the above technical problems, the present invention has isolated for the first time a uniform purslane polysaccharide with a novel structure through a specific extraction process, and found that the polysaccharide has good skin barrier repair effect.

[0005] In a first aspect, the present invention provides a purslane homogeneous polysaccharide having a chemical structure represented by the following general formula:

[0006]

[0007] Among them, n=8, m=19.

[0008] Preferably, the highest peak molecular weight Mp, weight average molecular weight Mw and number average molecular weight Mn of the purslane homogeneous polysaccharide are 6.4 kDa, 7.4 kDa and 5.3 kDa, respectively.

[0009] Preferably, the purslane homogeneous polysaccharide is mainly composed of glucose, galactose and arabinose, with molar proportions of 21.54%, 62.98% and 13.21%, respectively.

[0010] Preferably, the purslane homogeneous polysaccharide is obtained from Portulacaceae, Portulaca purslane Portulaca oleracea The dried aerial part of L. is obtained by extraction, separation and purification. The dried aerial part refers to the other parts of the whole dried Purslane excluding the root.

[0011] The second aspect of the present invention provides the use of the above-mentioned purslane uniform polysaccharide in cosmetics, food or medicine.

[0012] In a third aspect, the present invention provides a cosmetic comprising the above-mentioned uniform purslane polysaccharide.

[0013] Preferably, the cosmetic comprises phase A, phase B and phase C, wherein phase A comprises the following components by mass percentage:

[0014] water, 72.05%;

[0015] glycerol, 3.0%;

[0016] pentanediol, 2.0%;

[0017] Acrylates / C10-30 Alkyl Acrylate Crosspolymer, 0.25%;

[0018] p-Hydroxyacetophenone, 0.3%;

[0019] Phase B includes the following components by mass percentage:

[0020] Cetearyl alcohol, cetearyl glucoside, 2.0%;

[0021] polydimethylsiloxane, 3.0%;

[0022] Glyceryl tri(ethylhexanoate), 2.0%;

[0023] Glyceryl stearate, 1.5%;

[0024] squalane, 2.0%;

[0025] Steareth-21, 0.2%;

[0026] Phase C includes the following components by mass percentage:

[0027] water, 10.0%;

[0028] Bis-PEG-18 methyl ether dimethyl silane, 1.0%;

[0029] arginine, 0.2%;

[0030] Purslane homogeneous polysaccharide, 0.5%.

[0031] In a fourth aspect, the present invention provides a method for preparing the above-mentioned purslane uniform polysaccharide, comprising the following steps:

[0032] Step S1, crushing purslane and extracting purslane crude polysaccharide using water extraction and alcohol precipitation method, named WPOP;

[0033] Step S2: Subject the crude purslane polysaccharide to ion exchange column chromatography to obtain the initial purslane polysaccharide, named WPOP-1;

[0034] Step S3: Subject the initial purslane polysaccharide to gel filtration column chromatography to obtain the homogeneous purslane polysaccharide, named WPOP-1-1.

[0035] Preferably, step S1 is specifically as follows: Add deionized water with a weight 20 times that of purslane thereto, heat and stir for reflux extraction at 95 °C for two hours, concentrate the obtained extract, centrifuge at a speed of 11000 r / min for 10 min, take the supernatant, then add 95% ethanol with a volume 4 times that of the supernatant thereto, precipitate at 4 °C for 12 hours, centrifuge at a speed of 11000 r / min for 10 min, and dry the obtained precipitate to obtain the crude purslane polysaccharide.

[0036] Preferably, step S2 is specifically as follows: After loading the crude purslane polysaccharide onto a DEAE-52 column, use an aqueous NaCl solution as the eluent, elute and separate successively at concentrations of 0.1 M NaCl, 0.2 M NaCl, 0.3 M NaCl, and 0.4 M NaCl, with an elution speed of 15 mL / min, collect the eluent, collect 20 tubes for each eluent gradient, with 10 mL in each test tube. The eluent in tubes 6-18 of the 0.1 M NaCl elution part is concentrated under reduced pressure and dried to obtain the initial purslane polysaccharide.

[0037] Preferably, step S3 is specifically as follows: After loading the initial purslane polysaccharide onto a Sephadex G-75 column, elute with ultrapure water, with a column flow rate of 2.0 mL / min, collect the eluent, with 5 mL in each test tube. Tubes 10-14 are dried to obtain the homogeneous purslane polysaccharide.

[0038] Preferably, in step S2, dissolve the crude purslane polysaccharide in distilled water to form an aqueous solution with a concentration of 50 mg / mL, then centrifuge at 8000 rpm for 10 min, and then filter with a 0.45 μm microporous membrane, and take the filtrate to load onto a DEAE-52 column; in step S3, dissolve the initial purslane polysaccharide in distilled water to form an aqueous solution with a concentration of 50 mg / mL, then centrifuge at 8000 rpm for 10 min, and then filter with a 0.45 μm microporous membrane, and take the filtrate to load onto a Sephadex G-75 column, and the specification of this column is φ2.6×100 cm.

[0039] Compared with the prior art, the present invention has at least the following beneficial effects:

[0040] The innovative method of the present invention was applied to extract and purify the dried aerial parts of Portulaca oleracea L., and a novel-structured homogeneous polysaccharide from Portulaca oleracea L. was obtained. Through cell experiments and animal experiments, it was determined that it has the effect of promoting the scratch healing of Hacat cells and repairing skin barrier damage, and has important application potential in cosmetics, food and pharmaceuticals. Description of the Drawings

[0041] Figure 1 The elution curve of WPOP on the DEAE-52 chromatography column, the elution curve of WPOP-1 on the Sephadex G-75 column chromatography, the molecular weight test chart of the homogeneous polysaccharide WPOP-1-1 from Portulaca oleracea L. and the related molecular weight calibration curve: (A) The elution curve of WPOP on the DEAE-52 chromatography column; (B) The elution curve of WPOP-1 on the Sephadex G-75 column chromatography; (C) The molecular weight test chart of the homogeneous polysaccharide WPOP-1-1 from Portulaca oleracea L.; (D1) The calibration curve of the weight-average molecular weight (Mw) of the homogeneous polysaccharide WPOP-1-1 from Portulaca oleracea L.; (D2) The calibration curve of the peak molecular weight (Mp); (D3) The calibration curve of the number-average molecular weight (Mn);

[0042] Figure 2 The monosaccharide composition analysis chart, infrared spectrum analysis chart, GC-MS analysis chart and secondary mass spectrum chart of WPOP-1-1: (A) Monosaccharide composition analysis chart; (B) Infrared spectrum analysis chart; (C1-C6) GC-MS analysis chart and secondary mass spectrum chart of WPOP-1-1;

[0043] Figure 3 For one-dimensional nuclear magnetic and two-dimensional nuclear magnetic resonance spectra: (A) One-dimensional nuclear magnetic 1 1H-NMR spectrum; (B) One-dimensional nuclear magnetic 13 13C-NMR spectrum; (C) Two-dimensional nuclear magnetic HSQC spectrum; (D) Two-dimensional nuclear magnetic COSY spectrum; (E) Two-dimensional nuclear magnetic TOCSY spectrum; (F) Two-dimensional nuclear magnetic HMBC spectrum; (G) Two-dimensional nuclear magnetic NOESY spectrum;

[0044] Figure 4 For the results of the cell scratch experiment of the homogeneous polysaccharide from Portulaca oleracea L.: (A) Schematic diagram of the cell scratch experiment (before and after testing); (B) Cell migration rate (indicating the healing rate) chart after cell scratching;

[0045] Figure 5 For the results of the experiment on the repair of skin barrier damage in mice by the homogeneous polysaccharide from Portulaca oleracea L.: (A) Chart of the content of hyaluronic acid (HA) detected by serum indexology in mice; (B) Chart of the content of filaggrin (FLG) detected by serum indexology in mice; (C) Schematic diagram of the trans-epidermal water loss (TEWL) detected by serum indexology in mice;

[0046] Figure 6Hematoxylin-eosin staining (HE), Masson staining, and toluidine blue staining diagrams of mouse tissue sections;

[0047] Figure 7 This is the structural schematic diagram of the homogeneous polysaccharide from Portulaca oleracea L. of the present invention. Detailed implementation manners

[0048] The technical solution of the present invention will be further described below in conjunction with the accompanying drawings and through specific implementation manners. However, the following examples are only simple examples of the present invention and do not represent or limit the scope of the claimed rights of the present invention. The scope of protection of the present invention is subject to the claims.

[0049] Unless otherwise specified, the raw materials and materials used in the embodiments of the present invention are purchased through general commercial channels.

[0050] Example 1: Extraction and purification of the homogeneous polysaccharide from Portulaca oleracea L.

[0051] 1. Extract the crude polysaccharide WPOP from Portulaca oleracea L. by the water extraction and alcohol precipitation method

[0052] Crush the dried Portulaca oleracea L. without roots and weigh 400 g. Extract it with 8 L of deionized water by stirring and refluxing at 95 °C for 2 h. After the extraction, collect the extract and repeat once. Combine the two extracts obtained and concentrate them to 500 mL with a rotary evaporator. Then centrifuge at a speed of 11000 r / min for 10 min and take the supernatant. Add 4 times the volume of 95% ethanol of the supernatant to the supernatant, stir well, and then let it stand at 4 °C for 12 h. Centrifuge at a speed of 11000 r / min for 10 min, discard the supernatant, place the precipitate in a vacuum drying oven at 60 °C, and after drying, grind it into a fine powder, which is the crude polysaccharide from Portulaca oleracea L., named WPOP.

[0053] 2. Purification of the homogeneous polysaccharide from Portulaca oleracea L.

[0054] 2.1 Prepare the primary polysaccharide WPOP-1 from Portulaca oleracea L. by ion exchange column chromatography

[0055] Pretreatment of the ion exchange chromatography packing: Add 300 g of DEAE sepharose FF (DEAE-52) to 600 mL of water and stir into a suspension. Then pour it into a Buchner funnel to pump out the liquid, and wash it with about 3 times the volume of ultrapure water relative to the suspension. Repeat the above operations several times until the packing has no alcohol smell. Transfer it to a beaker, add one-half to one time the volume of distilled water of the packing, and stir well for column packing.

[0056] Column packing and equilibration: Mix the filler obtained after the above pretreatment with water and slowly add it to the XK chromatography column (φ3.0×50cm). After complete sedimentation, connect the upper column head to the peristaltic pump. Start the pump at a flow rate of 250cm / h and flush the column with ultrapure water until the gel surface is stable to complete the column packing.

[0057] Loading and elution: The crude polysaccharide of Purslane was dissolved in distilled water to form a 50 mg / mL aqueous solution, then centrifuged at 8000 rpm for 10 min, filtered with a 0.45 μm microporous filter membrane, and the filtrate was loaded onto the equilibrated ion exchange chromatography column. The loading volume was 30% of the column volume. After all the sample liquid entered the chromatography column, it was eluted and separated using NaCl aqueous solution at different concentrations (0.1 M NaCl, 0.2 M NaCl, 0.3 M NaCl, 0.4 M NaCl) at an elution rate of 15 mL / min. An automatic fraction collector was used to collect the fractions, and 20 tubes were collected for each eluate gradient, with 10 ml collected in each tube. The phenol-sulfuric acid method was used, and the content of polysaccharides in each tube of eluate was detected by an enzyme reader at 490 nm, referred to as polysaccharide content. The polysaccharide elution curve was then obtained with the number of tubes as the horizontal axis and the absorbance as the vertical axis, as shown in the figure. Figure 1 A. Figure 1 As shown in A, the product obtained after 6 to 18 tubes of eluate were concentrated under reduced pressure and dried was designated as the primary polysaccharide WPOP-1 from Portulaca oleracea.

[0058] 2.2 Preparation of Portulaca oleracea homogeneous polysaccharide WPOP-1-1 by gel filtration column chromatography

[0059] Pretreatment of gel filtration chromatography filler: Add 100 g of gel filtration chromatography filler Chromdex75PG (dextran G-75) into 300 mL of water and stir to form a suspension. Pour into a Buchner funnel, drain the liquid, and wash with ultrapure water about 3 times the volume of the suspension. Repeat the above operation several times until the filler has no alcohol smell. Transfer to a beaker, add distilled water of one-half to one times the volume of the filler, and stir well for column loading.

[0060] Column packing and equilibration: Mix the filler obtained after the above pretreatment with water and slowly add it to the XK chromatography column (φ2.6×100 cm). After complete sedimentation, connect the upper column head to the chromatography system and flush the column with ultrapure water at a flow rate of 30 cm / h until the gel surface is stable. The column packing is completed.

[0061] Sample loading and elution: The crude polysaccharide WPOP-1 from Portulaca oleracea L. prepared by ion exchange column chromatography was dissolved in distilled water to form an aqueous solution with a concentration of 50 mg / mL, centrifuged at 8000 rpm for 10 min, and then filtered through a 0.45 μm microporous membrane. The filtrate was loaded onto a pre-equilibrated gel filtration chromatography column. The sample loading volume was 1% of the column volume. After the sample solution completely entered the chromatography column, it was eluted and separated with ultrapure water at a flow rate of 2.0 mL / min for a (φ2.6×100 cm) column. An automatic fraction collector was used to collect the eluate, with 5 mL collected in each tube. The phenol-sulfuric acid method was adopted, and the polysaccharide content in each tube of the eluate was detected at 490 nm using an enzyme-linked immunosorbent assay reader. With the tube number as the abscissa and the absorbance as the ordinate, a polysaccharide elution curve was obtained, as shown in Figure 1 Figure B.

[0062] As Figure 1 shown in Figure B, the eluates from tubes 10 to 14 were combined and collected, concentrated under reduced pressure, and freeze-dried under vacuum to obtain the homogeneous polysaccharide WPOP-1-1 from Portulaca oleracea L., with a yield of 0.2% relative to the medicinal material (dried Portulaca oleracea L. without roots). The properties of the homogeneous polysaccharide from Portulaca oleracea L. are: white solid, odorless, and easily soluble in water.

[0063] Example 2: Structural analysis of the homogeneous polysaccharide from Portulaca oleracea L.

[0064] 1. Experimental method

[0065] 1.1 Molecular weight and its distribution

[0066] The molecular weight and distribution of the homogeneous polysaccharide from Portulaca oleracea L. prepared in Example 1 were analyzed by HPGPC-RID.

[0067] Reagent preparation: 0.05 M aqueous NaCl solution and 0.1 M aqueous NaNO3 solution were respectively prepared, and then filtered through a 0.22 μm membrane and the filtrates were ultrasonically treated for 20 min.

[0068] Sample and standard preparation: 5.0 mg of the homogeneous polysaccharide WPOP-1-1 was dissolved in 1.0 mL of 0.05 M NaCl solution to prepare a test solution with a concentration of 5.0 mg / mL, then centrifuged at 8000 rpm for 10 min, and further filtered through a 0.22 μm microporous membrane. The filtrate was placed in a 2.0 mL injection vial for standby.

[0069] Chromatographic method: The chromatographic column was an OHpak SB-803 gel chromatography column (8 × 300 mm), the mobile phase was 0.05 M NaCl solution, the flow rate was 0.65 mL / min, the column temperature was 40 °C, the injection volume was 30 μL, and the detector was a Waters2410 differential refractive index detector. The results of the molecular weight and distribution are shown in Figure 1 Figure C.

[0070] AsFigure 1 As shown in C, the polysaccharide WPOP-1-1 exhibits a single symmetrical chromatographic peak, indicating that this polysaccharide is a homogeneous polysaccharide.

[0071] Figure 1 In D1 is the calibration curve of the weight-average molecular weight (Mw) of WPOP-1-1, Figure 1 In D2 is the calibration curve of the molecular weight at the highest peak (Mp), Figure 1 In D3 is the calibration curve of the number-average molecular weight (Mn). The Mp, Mw, and Mn of WPOP-1-1 were calculated to be 6.4 kDa, 7.4 kDa, and 5.3 kDa respectively according to the standard curve.

[0072] 1.2 Monosaccharide composition analysis

[0073] The monosaccharide composition of the homogeneous polysaccharide of Portulaca oleracea prepared in Example 1 was analyzed by high performance liquid chromatography.

[0074] Sample preparation: Accurately weigh 5.0 mg (± 0.05 mg) of the homogeneous polysaccharide WPOP-1-1, add 1.0 mL of 2 M trifluoroacetic acid (TFA) solution, heat at 121 °C for 2 h, dry with nitrogen, then add 3.0 mL of methanol for washing, and dry again. Wash with methanol repeatedly 2 - 3 times, add 5.0 mL of sterile water to dissolve, and transfer to a chromatographic vial for measurement.

[0075] Chromatographic conditions: Thermo U3000 liquid chromatography system, the chromatographic column is ZORBAX Eclipse XDB-C18, the mobile phase is acetonitrile∶phosphate buffer (12 g / L potassium dihydrogen phosphate and 2 M NaOH solution, pH = 6.8) = 1:1, isocratic elution, the flow rate is 0.8 mL / min, the column temperature is 30 °C, the detection wavelength is 250 nm, and the injection volume is 10 μL. The results are shown in Figure 2 A.

[0076] As Figure 2 shown in A, WPOP-1-1 is mainly composed of glucose, galactose, and arabinose, and the molar ratios are 21.54%, 62.98%, and 13.21% respectively.

[0077] 1.3 Methylation analysis

[0078] The linkage mode of the homogeneous polysaccharide of Portulaca oleracea prepared in Example 1 was analyzed by GC-MS.

[0079] Sample methylation: 1.0 mg of the sample, homogeneous polysaccharide from Portulaca oleracea, was accurately weighed and dissolved in 500 μL of dimethyl sulfoxide (DMSO). 1.0 mg of NaOH was then added and incubated for 0.5 h. 50 μL of iodomethane solution was added and reacted for 1 h. 1 mL of water and 2 mL of dichloromethane were added, vortexed, centrifuged, the aqueous phase was discarded, and the water phase was washed three times with water. The dichloromethane layer was evaporated to dryness, 100 μL of TFA (2.0 M) solution was added, and the reaction was carried out at 121°C for 90 min. The mixture was evaporated to dryness at 30°C, 50 μL of ammonia (2.0 M) and 50 μL of sodium borodeuteride (NaBD4) (1.0 M) solution were added, mixed, and reacted at room temperature for 2.5 h. 20 μL of acetic acid was added to terminate the reaction, and the mixture was dried under nitrogen. 250 μL of methanol was washed twice, dried under nitrogen, 250 μL of acetic anhydride was added, vortexed, and the mixture was reacted at 100°C for 2.5 h. 1 mL of water and let it stand for 10 min, add 500 μL of dichloromethane, vortex, centrifuge, discard the aqueous phase, and repeat the water washing three times.

[0080] Chromatographic conditions: An Agilent 7890A gas chromatography system (Agilent, USA) was used, with an HP-5MS column (30 cm × 0.25 mm × 0.25 μm). The carrier gas was high-purity helium at a flow rate of 1.0 mL / min, an inlet temperature of 260°C, an injection volume of 1.0 μL, split injection (split ratio 10:1), and a temperature program (50°C for 1.0 min, then 50°C / min to 130°C, then 3°C / min to 230°C and hold for 2 min).

[0081] Mass spectrometry detection conditions: An Agilent 5977B quadrupole mass spectrometer (Agilent, USA) equipped with an electron impact ion source (EI) and a MassHunter workstation was used. The EI inlet temperature was 230°C, the quadrupole temperature was 150°C, the electron energy was 70 eV, the scanning mode was full scan (SCAN), and the mass scan range (m / z): 30-600. Results are shown in Figure 2 Middle C1.

[0082] Figure 2 C1-C6 represent the GC-MS analysis and secondary mass spectrometry of WPOP-1-1. The main glycosidic bond types of WPOP-1-1 are 3-Ara(f), 5-Ara(f), t-Glc(p), t-Gal(p), and 4-Gal(p). Detailed glycosidic bond data are shown in Table 1.

[0083] Table 1. Methylation analysis of WPOP-1-1

[0084]

[0085] In Table 1 above, the Chinese name of 1,3,4-tri-O-acetyl-2,5-di-O-methyl arabinitol is 1,3,4-tri-O-acetyl-2,5-di-O-methyl arabinitol; the Chinese name of 1,4,5-tri-O-acetyl-2,3-di-O-methylarabinitol is 1,4,5-tri-O-acetyl-2,3-O-methyl arabinitol; the Chinese name of 1,5-di-O-acetyl-2,3,4,6-tetra-O-methyl glucitol is 1,5-di-O-acetyl-2,3,4,6-tetra-O-methyl glucitol; the Chinese name of 1,5-di-O-acetyl-2,3,4,6-tetra-O-methyl galactitol is 1,5-di-O-acetyl-2,3,4,6-tetra-O-methyl galactitol.

[0086] 1.4 Infrared Analysis

[0087] The dried polysaccharide sample WPOP-1-1 (1 - 2 mg) was ground and pressed into a tablet with 200 mg of KBr powder under an infrared lamp, and infrared scanning was performed in the wavelength range of 4000 - 400 cm -1 using a Nicolet 6700 Fourier transform infrared spectrometer (ThermoFisher, USA), and the infrared spectrum was recorded, as shown in Figure 2 Figure B.

[0088] As Figure 2 shown in Figure B, infrared spectrum analysis indicated that the polysaccharide sample had characteristic absorption peaks of polysaccharides: there was a strong and broad absorption peak at 3889.17 cm -1 , which was a strong absorption peak of O-H stretching vibration of intermolecular or intramolecular hydrogen bonds in the polysaccharide molecule; a medium-intensity sharp peak near 2929.59 cm -1 was the C-H stretching vibration absorption peak of methylene (-CH2); the absorption peak at 1647.22 cm -1 was the stretching vibration of the sugar ring of the carbohydrate; the absorption peaks in the range of 1450 - 1200 cm -1 , the absorption peaks at 1423.22 cm -1 , 1383.95 cm -1 , 1259.35 cm -1 , 1223.12 cm -1 were the out-of-plane bending vibration absorption peaks of C-H, which, together with the C-H stretching vibration, constituted the characteristic absorption of the sugar ring; the strong absorption peak between 1150 - 1010 cm -1 , the absorption peaks at 1073.23 cm -1 , 1046.88 cm-1 The presence of pyranosides was proven again at these two positions. The absorptions at these two positions are the bending vibrations of the C-O bond in the C-O-H or C-O-C structure; 890.14 cm -1 is the characteristic region of the β-pyranoside bond, and it is speculated that the polysaccharide contains β-type pyranose; 833.39 cm -1 is the C-H bending vibration peak of the pyranose α-anomer; 756.44 cm -1 shows the symmetric ring stretching vibration peak of the pyranose ring.

[0089] 1.5 Nuclear Magnetic Resonance Analysis

[0090] Dissolve 50 mg of the polysaccharide sample WPOP-1-1 in 0.5 mL of deuterium oxide and freeze-dry it. After drying, dissolve the freeze-dried powder in 0.5 mL of deuterium oxide again. Use acetone-d6 as the internal standard, and measure the 1D ( 1 H, 13 C) and 2D (HSQC, COSY, HMBC, NOESY, TCOSY) NMR spectra with a 600 MHz nuclear magnetic resonance spectrometer (AVANCE HD III, Bruker).

[0091] To further obtain the structural characteristic information of the sample, perform one-dimensional nuclear magnetic 1 H-NMR ( Figure 3 in A), 13 C-NMR ( Figure 3 in B) and two-dimensional nuclear magnetic HSQC ( Figure 3 in C), COSY ( Figure 3 in D), TOCSY ( Figure 3 in E), HMBC ( Figure 3 in F), NOESY ( Figure 3 in G) in order to obtain all the H and C chemical shift information of each main sugar residue and infer the connection sequence between each sugar residue.

[0092] Use one-dimensional nuclear magnetic resonance hydrogen spectrum ( 1 H-NMR) to further identify the glycosidic bond configuration of the polysaccharide sample. Most of the hydrogen spectrum signals of the polysaccharide are in the range of δ 3.0 - 5.5 ppm. Usually, the region between δ 4.5 - 5.5 ppm is the anomeric proton (H-1) resonance region. Analyze 1 H- 1H COSY, HSQC, and TOCSY can assign signals to the main sugar residues in the methylation results. In the HSQC spectrum, the anomeric signals of each sugar residue can be found, a total of 11 kinds, which are δ 5.31 ppm / δ 99.46 ppm, δ 5.28 ppm / δ 99.87 ppm, δ 4.88 ppm / δ 99.54 ppm, δ 4.95 ppm / δ 99.38 ppm, δ 4.55 ppm / δ 104.32 ppm, δ 5.06 ppm / δ 106.87 ppm, δ 5.10 ppm / δ 106.85 ppm, δ 5.06 ppm / δ 106.25 ppm, δ 5.13 ppm / δ 106.87 ppm, δ 5.03 ppm / δ 107.17 ppm, δ 5.00 ppm / δ 107.40 ppm. According to these anomeric signal peaks, combined with 1 H- 1 H COSY, HSQC, and TOCSY, the signals at other positions corresponding to the anomeric signals can be assigned. Combining the H and C signal characteristics of each position of the sugar residue and the methylation results, the sugar residues corresponding to these anomeric signals are respectively assigned as →4)-α-D-Glcp-(1→, →4,6)-α-D-Glcp-(1→, α-D-Glcp-(1→, α-D-Galp-(1→, →4)-β-D-Galp-(1→, α-L-Araf-(1→ with different linkage sites, →2,3,5)-α-L-Araf-(1→, →3)-α-L-Araf-(1→, →3,5)-α-L-Araf-(1→, →5)-α-L-Araf-(1→, marked as Glc 1,4 、Glc 1,4,6 、Glc t 、 α Gal t 、 β Gal 1,4 、A t 1 、A t 2 、A 1,2,3,5 、A 1,3 、A 1,3,5 、A 1,5 。

[0093] Taking the sugar residue Glc 1,4For example, the anomeric signals δ 5.31 ppm (H-1) and δ 99.46 ppm (C-1) indicate that the sugar residue has an α configuration. Through the COSY spectrum and TOCSY cross-peaks, the signals of H-2, H-3, H-4, and H-5 were identified. The chemical shifts of H-2, H-3, H-4, and H-5 of this sugar residue were assigned to δ 3.49 ppm, δ 3.87 ppm, δ 3.56 ppm, and δ 3.74 ppm, respectively. The signals of H6a and H6b were determined to be δ 3.75 ppm and δ 3.67 ppm through the COSY spectrum and HSQC spectrum. After assigning the chemical shifts of the hydrogens on the sugar ring, the chemical shifts of the carbons on the sugar ring were assigned through the HSQC correlation spectrum, which were δ 99.46 ppm, δ 71.29 ppm, δ 73.04 ppm, δ 76.73 ppm, δ 71.29 ppm, and δ 60.61 ppm, respectively. The chemical shifts of C-1 and C-4 shifted downfield, indicating that substitution occurred at positions C-1 and C-4 of the sugar ring. Combining with the methylation results, it was inferred that the sugar residue was →4)-α-D-Glcp-(1→. The hydrogen and carbon signals of other residues were derived in a similar manner. The summary of the chemical shift assignments of H and C for the main sugar residues in the sample is shown in Table 2.

[0094] Table 2. 1 H and 13 C Chemical Shift Assignments

[0095]

[0096] In the HMBC spectrum, H-1 (δ 5.31 ppm) of the sugar residue Glc 1,4 has a coupling signal with C-4 (δ 76.73 ppm) of the sugar residue Glc 1,4 (Glc 1,4 H-1 / Glc 1,4 C-4), indicating the existence of a connection between →4)-α-D-Glcp-(1→ and →4)-α-D-Glcp-(1→ sugar residues, and the connection site is at the O-4 position; H-1 (δ 5.31 ppm) of the sugar residue Glc 1,4 has a coupling signal with C-4 (δ 76.12 ppm) of the sugar residue Glc 1,4,6 (Glc 1,4 H-1 / Glc 1,4,6 C-4), indicating the existence of a connection between →4)-α-D-Glcp-(1→ and →4,6)-α-D-Glcp-(1→ sugar residues, and the connection site is at the O-4 position; H-1 (δ 4.88 ppm) of the sugar residue Glc t has a coupling signal with the sugar residue Glc1,4,6 at C-6 (δ 66.23 ppm) has a coupling signal (Glc t H-1 / Glc 1,4,6 C-6), indicating the presence of a linkage between α-D-Glcp-(1→ and →4,6)-α-D-Glcp-(1→ sugar residues, with the linkage site at O-6; the sugar residue Glc 1,4,6 of H-1 (δ 5.28 ppm) and the sugar residue β Gal 1,4 at C-4 (δ 77.56ppm) has a coupling signal (Glc 1,4,6 H-1 / β Gal 1,4 C-4), indicating the presence of a linkage between →4,6)-α-D-Glcp-(1→ and →4)-β-D-Galp-(1→ sugar residues, with the linkage site at O-4; the sugar residue β Gal 1,4 of H-1 (δ 4.55 ppm) and the sugar residue β Gal 1,4 at C-4 (δ 77.56ppm) has a coupling signal( β Gal 1,4 H-1 / β Gal 1,4 C-4), indicating the presence of a linkage between →4)-β-D-Galp-(1→ and →4)-β-D-Galp-(1→ sugar residues, with the linkage site at O-4; the sugar residue A 1,5 of H-1 (δ 5.00 ppm) and the sugar residue Glc 1,4,6 at C-6 (δ 66.23 ppm) has a coupling signal (A 1,5 H-1 / Glc 1,4,6 C-6), indicating the presence of a linkage between →5)-α-L-Araf-(1→ and →4,6)-α-D-Glcp-(1→ sugar residues, with the linkage site at O-6; the sugar residue A 1,5 of H-1 (δ 5.00 ppm) and the sugar residue A 1,3,5 at C-5 (δ 66.16 ppm) has a coupling signal (A 1,5 H-1 / A 1,3,5 C-5), indicating the presence of a linkage between →5)-α-L-Araf-(1→ and →3,5)-α-L-Araf-(1→ sugar residues, with the linkage site at O-5; the sugar residue A 1,3,5 of H-1 (δ 5.03 ppm) and A 1,5 the sugar residue at C-5 (δ 66.23 ppm) has a coupling signal (A 1,3,5H-1 / A 1, 5 C-5), indicating the presence of a linkage between the →3,5)-α-L-Araf-(1→ and →5)-α-L-Araf-(1→ sugar residues, with the linkage site at O-5; the H-1 of sugar residue A 1,3 shows a coupling signal with the C-3 (δ 79.92 ppm) of sugar residue A 1,2,3,5 (H-1 / A 1,3 H-1 / A 1,2,3,5 C-3), indicating the presence of a linkage between the →3)-α-L-Araf-(1→ and →2,3,5)-α-L-Araf-(1→ sugar residues, with the linkage site at O-3; the H-1 of sugar residue A t 1 shows a coupling signal with the C-3 (δ 82.08 ppm) of sugar residue A 1,3,5 (H-1 / A t 1 H-1 / A 1,3,5 C-3), indicating the presence of a linkage between α-L-Araf-(1→ and →3,5)-α-L-Araf-(1→ sugar residues, with the linkage site at O-3; sugar residue α Gal t shows a coupling signal between its H-1 (δ 4.95 ppm) and the C-2 (δ 84.67 ppm) of sugar residue A 1,2,3,5 ( α Gal t H-1 / A 1,2,3,5 C-2), indicating the presence of a linkage between α-D-Galp-(1→ and →2,3,5)-α-L-Araf-(1→ sugar residues, with the linkage site at O-2; sugar residue α Gal t shows a coupling signal between its H-1 (δ 4.95 ppm) and the C-3 (δ 84.14 ppm) of sugar residue A 1, 3 ( α Gal t H-1 / A 1, 3 C-3), indicating the presence of a linkage between α-D-Galp-(1→ and →3)-α-L-Araf-(1→ sugar residues, with the linkage site at O-3.

[0097] In the NOESY spectrum, the H-1 (δ 5.03 ppm) of sugar residue A 1,3,5 shows a coupling signal with the H-5 (δ 3.80 ppm) of sugar residue A 1,5 (H-1 / A 1,3,5 H-1 / A 1, 5H-5), indicating the presence of a linkage between the →3,5)-α-L-Araf-(1→ and →5)-α-L-Araf-(1→ sugar residues, with the linkage site at O-5; the H-1 of sugar residue A 1,2,3,5 (δ 5.06 ppm) shows a coupling signal with the H-5 (δ 3.71 ppm) of sugar residue A 1,5 (A H-1 / A H-5), indicating the presence of a linkage between the →2,3,5)-α-L-Araf-(1→ and →5)-α-L-Araf-(1→ sugar residues, with the linkage site at O-5; the H-1 of sugar residue A 1,2,3,5 (δ5.13 ppm) shows a coupling signal with the H-3 (δ 79.92 ppm) of sugar residue A 1, 5 (A H-1 / A H-3), indicating the presence of a linkage between the →3)-α-L-Araf-(1→ and →2,3,5)-α-L-Araf-(1→ sugar residues, with the linkage site at O-3; the H-1 of sugar residue A 1,3 (δ 5.00 ppm) shows a coupling signal with the H-5 (δ 3.75 ppm) of sugar residue A 1,2,3,5 (A H-1 / A H-5), indicating the presence of a linkage between the →5)-α-L-Araf-(1→ and →3,5)-α-L-Araf-(1→ sugar residues, with the linkage site at O-5; the H-1 of sugar residue 1,3 Gal 1,2,3,5 (δ 4.95 ppm) shows a coupling signal with the H-3 (δ 3.86ppm) of sugar residue A 1,5 (Gal H-1 / A H-3), indicating the presence of a linkage between the α-D-Galp-(1→ and →3)-α-L-Araf-(1→ sugar residues, with the linkage site at O-3; the H-1 of sugar residue 1,3,5 Gal 1,5 (δ 4.55 ppm) shows a coupling signal with the H-4 (δ 4.08 ppm) of sugar residue 1,3,5 Gal α (Gal H-1 / t Gal 1, 3 Gal H-3), α Gal t Gal 1, 3 Gal β Gal 1,4 Gal β Gal 1,4 Gal β Gal 1,4 Gal H-1 / β Gal 1,4H-4), indicating the presence of a linkage between →4)-β-D-Galp-(1→ and →4)-β-D-Galp-(1→ sugar residues, and the linkage site is at the O-4 position.

[0098] Based on the results of monosaccharide composition and methylation information, combined with the relevant signal information of NMR HMBC and NOESY, a possible structural model is proposed: the main chain of the polysaccharide structure is composed of →4)-α-D-Glcp-(1→ sugar residues and →4)-β-D-Galp-(1→ sugar residues, and there are branching sites at the C-6 position of some →4)-α-D-Glcp-(1→. There may be two types of polysaccharide side chain structures, one is α-D-Glcp-(1→, and the other is a glycan composed of galactose and arabinose.

[0099] Example 3: Cell Scratch Assay of Homogeneous Polysaccharide from Portulaca oleracea L.

[0100] 1. Source of experimental materials: Human immortalized keratinocytes (Hacat cells) were obtained from Wuhan Punosai Biotechnology Co., Ltd., and the culture medium was: 90% DMEM high glucose + 10% FBS (fetal bovine serum).

[0101] 2. Experimental grouping: Hacat cells were seeded in six-well plates and divided into 5 groups: blank control group, model group, low-dose, medium-dose, and high-dose (1.25 μg / mL, 2.5 μg / mL, 5 μg / mL) homogeneous polysaccharide groups of Portulaca oleracea L.

[0102] 3. Experimental method

[0103] Experiment on the promotion of wound healing of Hacat cells by homogeneous polysaccharide from Portulaca oleracea L.:

[0104] Take the 3rd generation cells. When the growth density of human immortalized keratinocytes reaches over 95%, seed the cells in sterile labeled 6-well plates at a density of 1×10 5 cells / mL, and place the 6-well plates in an incubator at 37 °C and 5% CO2 for 24 h. After the human immortalized keratinocytes are completely adherent, use a pipette tip to scratch each well and wash the cells with PBS. Then, intervene with 0, 1.25, 2.5, 5 μg / mL of the homogeneous polysaccharide from Portulaca oleracea L. for 24 h. After the intervention, discard the old culture medium, gently wash 3 times with PBS for 3 min each time, and observe and take pictures of the cell position changes under a microscope.

[0105] 4. Model establishment and drug administration method

[0106] Blank control group (control): Use a pipette tip to scratch the blank well, and then do not give any intervention.

[0107] Experimental group: (low, medium, and high doses of homogeneous polysaccharide from Portulaca oleracea L.): After making scratches in each well using a pipette tip, the homogeneous polysaccharide from Portulaca oleracea L. was administered at low dose (1.25 μg / mL), medium dose (2.5 μg / mL), and high dose (5 μg / mL). The administration ended after 24 h.

[0108] 5. Experimental results

[0109] The comparison results before and after the scratch experiment are shown in Figure 4 Figure A. Figure 4 In Figure A, the area between the two vertical lines represents the scratched area.

[0110] As can be seen from Figure 4 Figure A, compared with the blank group, the healing areas of the homogeneous polysaccharide from Portulaca oleracea L. treatment groups (1.25, 2.5, 5 μg / mL) were significantly increased, and the differences were statistically significant (P<0.05), showing time- and concentration-dependence. It indicates that the Hacat cells intervened with the homogeneous polysaccharide from Portulaca oleracea L. can lead to enhanced cell migration ability.

[0111] Calculated from Figure 4 Figure A is the scratch healing rate shown in Figure 4 Figure B. The calculation formula is: Healing rate % = 100% - (Scratch area at the end / Scratch area at the start of the experiment) %.

[0112] As can be seen from Figure 4 Figure B, compared with the blank control group, the healing rates of the homogeneous polysaccharide from Portulaca oleracea L. treatment groups (1.25, 2.5, 5 μg / mL) were all greater than that of the blank control group. There were significant differences in the medium- and high-dose groups of Portulaca oleracea L. ( * P<0.05, ** P<0.01), and the results showed a good dose-dependence.

[0113] Example 4: Experiment on the repair of skin barrier damage in mice by homogeneous polysaccharide from Portulaca oleracea L.

[0114] 1. Sources of experimental materials: 36 ICR mice (female, 6 - 8 weeks old) were provided by Liaoning Changsheng Biotechnology Co., Ltd.; the Portulaca oleracea L. plants were provided by Yunnan Qiancaoyuan Pharmaceutical Co., Ltd.

[0115] 2. Experimental grouping: The ICR mice were randomly divided into 6 groups, with 6 mice in each group, namely blank control group, model group, positive control group, and low-, medium-, and high-dose (50 mg / kg, 100 mg / kg, 200 mg / kg) groups.

[0116] 3. Experimental methods

[0117] Mouse damaged skin model establishment: Select 30 healthy female ICR mice weighing 20 - 30 g, and intraperitoneally inject 1.0 mL of sodium pentobarbital aqueous solution. After the mice enter the anesthetic state, fix the mice, cut off the hair in a circular area about 3 cm in diameter in the center of their backs. After disinfecting with povidone iodine, cut off a circular skin tissue with a diameter of 1.5 cm in the depilated area, expose it to the air without any interference, and establish a mouse skin damage model.

[0118] Blank control group (control): Do not establish a model, freely drink water, and give intragastric administration of sterile water.

[0119] Model group (model): Establish a skin damage model according to the model establishment method.

[0120] Positive group (mometasone furoate cream, MFC): Establish a skin damage model according to the method of the model group, and start applying mometasone furoate cream at 200 μL per mouse from the day of model establishment.

[0121] Experimental group (low, medium, and high dose groups of Portulaca oleracea homogeneous polysaccharide): Establish a skin damage model according to the method of the model group, and start giving low-dose (50 mg / kg body weight), medium-dose (100 mg / kg body weight), and high-dose (200 mg / kg body weight) Portulaca oleracea homogeneous polysaccharide (prepared by adding sterile water to Portulaca oleracea homogeneous polysaccharide) at 200 μL per mouse from the day of model establishment.

[0122] 4. Specific sampling operation

[0123] On the 20th day, use a TE007 Swiss SKT skin moisture loss meter to measure the transdermal water loss of each mouse. On the 21st day, which is the end point of the experiment, collect mouse serum and use ELISA to measure the expression levels of FLG and HA in the mouse serum; and cut off the damaged skin to compare the HE, Masson, and toluidine blue staining of mouse tissue sections among groups.

[0124] 5. Experimental results

[0125] Figure 5 In Figure A and B are the content graphs of detecting HA and FLG by serum indexology. From Figure 5 Figure A and B, it can be seen that compared with the blank group, the contents of both in the model group decreased significantly ( # P < 0.05, ### P < 0.001), and compared with the model group, the contents of HA and FLG in the high, medium, and low dose groups of Portulaca oleracea homogeneous polysaccharide all increased, and the differences were statistically significant ( * P < 0.05, ** P < 0.01, ***P < 0.001). It shows that after administration of the homogeneous polysaccharide from Portulaca oleracea L., the production of hyaluronic acid and filaggrin in mice can be repaired.

[0126] Figure 5 In it, C is the TEWL value of mouse skin. Trans Epidermal Water Loss (TEWL), also known as transepidermal water loss, is a commonly used indicator reflecting the barrier function of the stratum corneum of the skin and is also the most intuitive value reflecting the skin barrier repair ability. From Figure 5 it can be seen that the value of the model group is significantly higher than that of the blank control group ( ### P < 0.001). After administration of low, medium and high doses of the homogeneous polysaccharide from Portulaca oleracea L. and the positive group, the value gradually decreases, and the difference is statistically significant ( * P < 0.05, ** P < 0.01, *** P < 0.001), and it shows a good dose-dependence.

[0127] Figure 6 They are the hematoxylin-eosin staining (HE), Masson staining and toluidine blue staining diagrams of the skin tissue sections of each group of mice. From Figure 6 the HE staining, it can be seen that after modeling, there is inflammatory cell infiltration in the model group, the skin epidermis and dermis are swollen and thickened, there are fewer collagen fibers in the dermis, which are distorted, broken and disorderly arranged, and the skin barrier is damaged. Compared with the model group, the positive group, the low, medium and high dose groups of the homogeneous polysaccharide from Portulaca oleracea L. are significantly improved. From the Masson staining, it can be seen that after modeling, the collagen fibers in the dermis tissue of the model group are loose and unevenly distributed, while the collagen fiber morphology of the positive group, the low, medium and high dose groups of the homogeneous polysaccharide from Portulaca oleracea L. and the control group is relatively regular and basically returns to normal. The collagen fibers are significantly thickened and widened, and the collagen fibers in the high dose group and the positive group are arranged regularly and orderly, and the morphology is similar to that of the blank control group. From the toluidine blue staining, it can be seen that after modeling, the number of mast cells in the model group is relatively large. Compared with the model group, the number of mast cells in the positive group, the low, medium and high dose groups of the homogeneous polysaccharide from Portulaca oleracea L. is reduced to a certain extent. Among them, the number of mast cells in the high dose group is significantly reduced and basically returns to normal.

[0128] Figure 5 and Figure 6 The results both show that the model is successfully established, and the skin barrier of the experimental group mice is significantly repaired, indicating that the homogeneous polysaccharide from Portulaca oleracea L. can repair the skin barrier damage of model mice.

[0129] Example 5: Application of the homogeneous polysaccharide from Portulaca oleracea L.

[0130] The homogeneous polysaccharide from Portulaca oleracea L. obtained in Example 1 is applied to the cosmetic facial cream. The component ratios of the cream formula are shown in Table 3 below:

[0131] Table 3. Composition Table of Facial Cream

[0132]

[0133] Preparation method of cosmetic cream: Heat the raw materials of phase A and phase B to 80°C - 85°C respectively. After the two phases are completely dissolved and stirred evenly, transfer the raw materials of phase B to phase A, homogenize at 5000 rpm for 5 minutes in a homogenizer. After being mixed evenly, stir and cool to 40°C - 45°C, then add the raw materials of phase C, and continue to stir until evenly mixed to obtain a cosmetic cream containing portulaca homopolysaccharide.

[0134] The applicant declares that the above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by any person skilled in the art within the technical scope disclosed by the present invention fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A homogenous polysaccharide from Portulaca oleracea L., characterized in that, The Portulaca oleracea homogeneous polysaccharide has a structure represented by the following general formula: ， where n = 8 and m = 19; The Portulaca oleracea homogeneous polysaccharide is mainly composed of glucose, galactose and arabinose, and the molar ratios are 21.54%, 62.98% and 13.21% respectively; The Portulaca oleracea homogeneous polysaccharide with the structure represented by the general formula has the efficacy of promoting the scratch healing of Hacat cells and repairing skin barrier damage.

2. The uniform polysaccharide of Portulaca oleracea as described in claim 1, characterized in that, The peak molecular weight Mp, weight average molecular weight Mw and number average molecular weight Mn of the Portulaca oleracea homogeneous polysaccharide are 6.4 kDa, 7.4 kDa and 5.3 kDa respectively.

3. The purslane homogeneous polysaccharide according to claim 1, wherein The purslane homogeneous polysaccharide is obtained by extraction, separation and purification from the dried aerial parts of Portulaca L. of the family Portulacaceae Portulaca oleracea L.

4. Use of the Portulaca oleracea homogeneous polysaccharide according to any one of claims 1 to 3 in cosmetics or food.

5. A cosmetic, characterized in that, The cosmetics include the Portulaca oleracea homogeneous polysaccharide according to any one of claims 1 to 3.

6. The cosmetic according to claim 5, characterized in that, The cosmetics include a phase A, a phase B and a phase C. Among them, by mass percentage, the phase A includes the following components: Water, 72.05%; Glycerol, 3.0%; Pentylene glycol, 2.0%; Acrylate / C10-30 alkyl acrylate cross-linked polymer, 0.25%; p-Hydroxyacetophenone, 0.3%; By mass percentage, the phase B includes the following components: Cetearyl alcohol and cetearyl glucoside, 2.0%; Polydimethylsiloxane, 3.0%; Triglyceride (ethylhexanoate), 2.0%; Glyceryl stearate, 1.5%; Squalane, 2.0%; Steareth-21, 0.2%; By mass percentage, the phase C includes the following components: Water, 10.0%; Bis-PEG-18 methyl ether dimethylsilane, 1.0%; Arginine, 0.2%; Portulaca oleracea homogeneous polysaccharide, 0.5%.

7. The preparation method of the purslane homogeneous polysaccharide according to any one of claims 1 to 3, characterized in that, Including the following steps: Step S1: After pulverizing Portulaca oleracea, use the water extraction and alcohol precipitation method to extract the crude polysaccharide of Portulaca oleracea; Step S2: Pass the crude polysaccharide of Portulaca oleracea through an ion exchange column chromatography to obtain the primary polysaccharide of Portulaca oleracea; Step S3: Pass the primary polysaccharide of Portulaca oleracea through a gel filtration column chromatography to obtain the Portulaca oleracea homogeneous polysaccharide.

8. The preparation method of the uniform polysaccharide of Portulaca oleracea L. according to claim 7, wherein, The specific content of step S1 is as follows: Add 20 times the weight of deionized water to the Portulaca oleracea, heat and stir for reflux extraction at 95 °C for two hours, then concentrate the obtained extract and centrifuge it at a speed of 11000 r / min for 10 min. Take the supernatant, then add 4 times the volume of 95% ethanol to the supernatant, precipitate at 4 °C for 12 hours, centrifuge it at a speed of 11000 r / min for 10 min, and dry the obtained precipitate to obtain the crude polysaccharide of Portulaca oleracea; The specific steps of step S2 are as follows: After loading the crude purslane polysaccharide onto a DEAE-52 column, use an aqueous NaCl solution as the eluent, and elute and separate it successively according to the concentrations of 0.1 M NaCl, 0.2 M NaCl, 0.3 M NaCl, and 0.4 M NaCl. The elution speed is 15 mL / min. Collect the eluent, collect 20 tubes for each eluent gradient, with 10 mL in each test tube. The eluent of tubes 6-18 in the 0.1 M NaCl elution part is concentrated under reduced pressure and dried to obtain the crude purslane polysaccharide; The specific steps of step S3 are as follows: After loading the crude purslane polysaccharide onto a Sephadex G-75 column, elute it with ultrapure water. The column flow rate is 2.0 mL / min. Collect the eluent, with 5 mL in each test tube. After drying tubes 10-14, the homogeneous purslane polysaccharide is obtained.

9. The preparation method of the uniform polysaccharide from Portulaca oleracea L. according to claim 7, characterized in that, In step S2, dissolve the crude purslane polysaccharide in distilled water to form an aqueous solution with a concentration of 50 mg / mL, then centrifuge it at 8000 rpm for 10 min, and then filter it through a 0.45 μm microporous membrane. Take the filtrate and load it onto a DEAE-52 column; In step S3, dissolve the crude purslane polysaccharide in distilled water to form an aqueous solution with a concentration of 50 mg / mL, then centrifuge it at 8000 rpm for 10 min, and then filter it through a 0.45 μm microporous membrane. Take the filtrate and load it onto a Sephadex G-75 column with a specification of φ2.6×100 cm.

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