Ionizing radiation degradation preparation method of high-biological-activity polygonatum sibiricum oligosaccharide
Through ionizing radiation degradation, the problem of difficult to industrial production of Polygonatum oligosaccharides was solved, and efficient, environmentally friendly and low-cost Polygonatum oligosaccharides were achieved, and high-biologically active Polygonatum oligosaccharides were obtained, which solved the existing technology. Enzyme degradation is a problem of environmental sensitivity and high equipment requirements.
Patent Information
- Application Number
- CN202411408027.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-10
- Publication Date
- 2024-12-10
AI Technical Summary
In the prior art, the degradation of polina oligosaccharides is difficult to achieve industrial production, and the enzyme degradation method is sensitive to the environment, has high equipment requirements, high cost, and is low in efficiency and high pollution, making it difficult to obtain high biologically active polina oligosaccharides.
The degradation method of ionizing radiation is used to cause the breakage of the polysaccharide chain and the formation of hydroxyl radicals through ionizing radiation, and the rapid and controllable degradation of polysaccharide is achieved to prepare highly biologically active polysaccharide oligosaccharide.
It realizes efficient, environmentally friendly and low-cost preparation of Polygonatum oligosaccharides, with mild reaction conditions, high product quality, good biocompatibility, and the degradation process can be synchronized to complete extraction and sterilization, saving costs.
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Figure CN119101263A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of preparation of main functional components of traditional Chinese medicine, and relates to a preparation method of degrading polygonatum sibiricum polysaccharide, a main functional component in natural polygonatum sibiricum, into polygonatum sibiricum oligosaccharides with wider and higher biological activity, in particular to a new method for preparing polygonatum sibiricum oligosaccharides by using irradiation degradation as a preparation process, which is environmentally friendly and efficient. Background Art
[0002] Polysaccharides are a type of biological macromolecules connected by glycosidic bonds, with molecular weights ranging from 100,000 to millions. They are commonly found in higher plants, microorganisms, animals and other biological organisms. They are structural substances and energy substances of cells. Therefore, the composition of life is inseparable from polysaccharides. For a long time, people's understanding of polysaccharides was limited to energy substances and structural materials. It was not until the 1970s that people broke through the shackles of traditional concepts and found that polysaccharides exist in all cell membranes. At the same time, polysaccharides also participate in various life activities in cells and have multiple biologically active functions. A large number of pharmacological experiments have shown that polysaccharide compounds have immune enhancement and regulation, anti-tumor, anti-virus, anti-coagulation, anti-radiation, anti-aging and other effects.
[0003] Polygonatum sibiricum is a traditional Chinese medicine with medicinal and edible properties. It belongs to the genus Polygonatum of the Liliaceae family, and its main medicinal part is the dried rhizome. Polygonatum sibiricum was first recorded in the "Famous Doctors' Records" in the late Han Dynasty more than 1,800 years ago. The main active ingredients of Polygonatum sibiricum include various compounds such as Polygonatum sibiricum polysaccharides, Polygonatum flavonoids and Polygonatum sibiricum saponins. Among them, Polygonatum sibiricum polysaccharides are considered to be the most important chemical component in Polygonatum sibiricum that exerts its pharmacological effects due to its high content and wide range of effects. Polygonatum sibiricum polysaccharides have good medicinal effects in antibacterial and anti-inflammatory, antioxidant, hypoglycemic, anti-tumor and immunomodulatory aspects.
[0004] Polygonatum sibiricum polysaccharide has a large molecular weight, large volume, and poor water solubility, which is not conducive to biological absorption. In recent years, many studies have found that the molecular weight of Polygonatum sibiricum polysaccharide is closely related to biological activity. In comparison, low molecular weight Polygonatum sibiricum polysaccharide, namely Polygonatum sibiricum oligosaccharide, has higher biological activity and relatively enhanced pharmacological effects. The biological activity of high molecular weight Polygonatum sibiricum polysaccharide can be improved by changing its molecular weight through degradation, so it is of great significance to study the degradation of Polygonatum sibiricum polysaccharide.
[0005] Chinese patent CN101293070B provides a method of extracting a polysaccharide from a polysaccharide to enhance immune function. The technical solution is to take a processed product of a polysaccharide, crush it, add 50-95% ethanol to perform ultrasonic or reflux extraction twice, filter it, decompress the filtrate and concentrate it until there is no alcohol taste, distill water is used to make the volume equivalent to 1g / ml, apply a macroporous adsorption resin to the aqueous solution, wash it with water, collect the washing liquid, and concentrate it to a thick paste to obtain a brown oligosaccharide extract with a yield of 9.0% to 13.6%. According to HPLC, the extract mainly contains small molecular sugars such as fructose, glucose, sucrose, and raffinose. After drying the extract, powdered polysaccharide is obtained. In fact, the ultrasonic degradation method is used, which has high requirements for equipment and instruments, resulting in high production costs and is not conducive to actual production.
[0006] Chinese patent CN112480283A provides a method for preparing neutral oligosaccharides from polygonatum. The method comprises the following steps: (1) extracting the polygonatum raw material and performing solid-liquid separation to obtain an extract, concentrating, freezing, melting and solid-liquid separation of the extract, and collecting the clear liquid; (2) passing the clear liquid through a large-pore membrane and a small-pore membrane in turn after enzyme column chromatography, and collecting the retentate respectively; (3) passing the small-pore membrane retentate through an ion exchange resin, and then adjusting the pH to 6-7, and then concentrating, precipitating with alcohol and drying. The yield of neutral oligosaccharides from polygonatum is not less than 10%, the total sugar purity is not less than 80%, and the proportion of neutral polysaccharides is not less than 80%. The actual use of this method is degradation by polysaccharide degrading enzymes. The enzymes themselves are sensitive to the environment (temperature, enzyme concentration, substrate concentration, pH, etc.), which can easily affect the catalytic reaction rate and even cause the catalytic ability of the enzyme to disappear.
[0007] Chinese patent CN111406820A provides a method for degrading polygonatum to obtain polygonatum oligosaccharides, and polygonatum oligosaccharides are prepared from the following components in mass ratio: 80-90% polygonatum slices, 10-20% cooked rehmannia paste, some cellulase, and some distilled water. The preparation method is as follows: processing polygonatum; enzymatic filtration; reduced pressure concentration; uniform mixing; granulation and packaging. The polygonatum oligosaccharide coffee prepared by the present invention not only makes the coffee drink have a unique flavor and smooth taste, but also enables some of the effective ingredients in the cooked rehmannia extract to be taken up and utilized by the human body together with coffee, resulting in the effects of lowering blood pressure, lowering blood sugar, lowering blood lipids, preventing atherosclerosis, delaying aging and improving immunity, which is beneficial to health. The actual use of this method is cellulase for biodegradation. This patent, like the previous polysaccharide degradation enzyme method, belongs to the enzyme degradation method. Compared with other degradation methods, although the reaction conditions are mild, no large amount of reagents need to be added. However, since the enzyme itself is sensitive to the environment, many factors will affect the catalytic reaction rate of the enzyme and even cause the enzyme's catalytic ability to disappear. This places strict demands on production conditions and is not conducive to mass production.
[0008] There are many methods for polysaccharide degradation, and their advantages and disadvantages are also different. At present, the means of studying polysaccharide degradation mainly include chemical degradation, biological degradation and physical degradation. Chemical degradation methods mainly include acid degradation, free radical method and oxidation method. Among them, hydrochloric acid, sulfuric acid, periodic acid, trifluoroacetic acid, acetic acid, etc. can be used in acid degradation. Hydrogen peroxide is the representative of oxidative degradation. The acid degradation method has problems such as a wide distribution of polysaccharide molecular weights, difficulty in separation and purification, high cost, and high pollution. The process conditions of the free radical method and the oxidative degradation method are more complex and difficult to control, and the repeatability and stability of the reaction are relatively poor. The biodegradation method is mainly the enzyme degradation method. Compared with other degradation methods, the enzyme degradation method has mild reaction conditions, fast degradation speed, and does not require a large amount of reagents. However, since the enzyme itself is sensitive to the environment, various factors such as temperature, enzyme concentration, substrate concentration, and pH value will affect the catalytic reaction rate of the enzyme, and even cause the catalytic ability of the enzyme to disappear, strict production conditions are required, which increases the production cost. The physical degradation method mainly includes physical means such as ultrasound and radiation degradation. In recent years, ultrasonic degradation has been widely used. By controlling the power and time, macromolecules can be effectively cut into substances with lower molecular weight to achieve degradation. There are currently two views on the mechanism of ultrasonic degradation of polysaccharides: one is that the energy released when the cavity bursts can degrade the polymer; the other is that under the action of ultrasound, the high-speed movement of solvent molecules causes them to shear the polysaccharide bonds, thereby degrading. However, the ultrasonic degradation method has high requirements for the container, and there are problems such as noise and equipment amplification. The actual production also has problems of high cost and low efficiency. The ionizing radiation degradation method is a solid-phase reaction that does not require any additives. It is low-cost and pollution-free. The reaction is easy to control and the product quality is high. It does not affect the biocompatibility of the sugar after degradation, that is, it will not cause toxic effects on human tissues.
[0009] In order to overcome the problem that the degradation of Polygonatum sibiricum oligosaccharides is difficult to industrialize and to achieve efficient degradation to obtain Polygonatum sibiricum oligosaccharides, the process of degrading Polygonatum sibiricum polysaccharides by ionizing radiation has emerged. The ionizing radiation degradation process does not require the addition of any substances toxic to the human body, is pollution-free, has mild reaction conditions, can be carried out at room temperature, and has high industrial production efficiency, extremely low cost, and good production controllability.
[0010] The problem to be solved by the present invention is to disclose an ionizing radiation degradation process for degrading polygonatum polysaccharide, the main functional component in polygonatum, to obtain polygonatum oligosaccharides with high biological activity, which is highly efficient, environmentally friendly, pollution-free and extremely low-cost, so as to overcome the above-mentioned defects of the prior art.
[0011] After searching, there is no patent application in China that is identical to the present invention. Summary of the invention
[0012] The purpose of the present invention is to provide a method for preparing high biological activity polygonatum oligosaccharides by ionizing radiation degradation in view of various problems existing in the prior art. The technical problem to be solved by the present invention is how to efficiently degrade and prepare the main functional component polygonatum oligosaccharides.
[0013] The purpose of the present invention can be achieved through the following technical solutions: a method for preparing highly biologically active Polygonatum sibiricum oligosaccharides by ionizing radiation degradation, characterized in that Polygonatum sibiricum polysaccharides are a biological macromolecule, and ionizing radiation can cause changes in their structure and function, mainly including the following two aspects of the influencing mechanism: 1. It promotes the breakage of the Polygonatum sibiricum polysaccharide chain: the energy of ionizing radiation is sufficient to cause the breakage of the β-1,4 glycosidic bond in the Polygonatum sibiricum polysaccharide molecule, resulting in the breakage of the molecular chain. The degree of breakage depends on the size of the radiation dose. 2. Hydroxyl free radical generation: a large number of hydroxyl free radicals are generated when ionizing radiation acts. Hydroxyl free radicals are highly reactive and can more accurately attack the β-1,4 glycosidic bonds in Polygonatum sibiricum polysaccharides, promoting the breakage of the chain. The synergistic effect of the two effects achieves the purpose of increasing the degradation rate of Polygonatum sibiricum polysaccharides and the efficiency of accurately preparing Polygonatum sibiricum oligosaccharides with a target molecular weight. A method for preparing highly biologically active Polygonatum sibiricum oligosaccharides by ionizing radiation degradation, comprising the following steps:
[0014] ① Weigh an appropriate amount of Polygonatum sibiricum, wash and slice it, freeze-dry it, and then crush and sieve it to obtain Polygonatum sibiricum powder.
[0015] ②Put the crushed and sieved Polygonatum powder into a PE bag and perform electron beam radiation extraction. The selected dose rate is 20kGy / pass and the radiation absorption dose is 0-320kGy.
[0016] ③ Add water with a solid-liquid ratio of 1:10-1:30 to the irradiated polygonatum powder, reflux extract 1-5 times, each extraction time is 1-3h, the extraction temperature is 70-110℃, and filter.
[0017] ④ The filtrate is concentrated under reduced pressure, precipitated with alcohol, and freeze-dried to obtain crude polygonatum polysaccharide.
[0018] ⑤ The obtained crude polygonatum polysaccharide is separated and purified using a DEAE-52 chromatography column, and then concentrated, ethanol precipitated, centrifuged, freeze-dried, and dried to obtain polygonatum polysaccharide.
[0019] ⑥ Take an appropriate amount of Polygonatum sibiricum polysaccharide, pack it into a bag and seal it, then use a 1MeV electron accelerator to irradiate and degrade it, select a dose rate of 20kGy / pass, and a total radiation absorption dose of 80-320kGy. After irradiation, go through an ultrafiltration system, rotary evaporation, alcohol precipitation, centrifugation, and freeze drying to obtain Polygonatum sibiricum oligosaccharide.
[0020] Furthermore, the average molecular weight of the polygonatum oligosaccharide is about 200 kDa.
[0021] Furthermore, the raw material of Polygonatum sibiricum is crushed and sieved using 30 mesh before irradiation to increase the surface area of Polygonatum sibiricum, thereby increasing its radiation contact surface and the contact area with water during extraction, which is beneficial to the dissolution of the effective ingredient Polygonatum sibiricum polysaccharide; at the same time, it also avoids excessive crushing that is not conducive to subsequent solid-liquid separation.
[0022] Further, the filtrate was concentrated under reduced pressure at 60°C, and after concentration, 4 times the volume of anhydrous ethanol solution was slowly added, and refrigerated at 4°C overnight.
[0023] Furthermore, the impregnated polygonatum polysaccharide is packaged in PE bags, sealed, and subjected to electron beam radiation degradation at 80 to 320 kGy.
[0024] Furthermore, the product was concentrated to 1 / 5 volume by rotary evaporation under reduced pressure at 50°C through an ultrafiltration system with a molecular cutoff of 200 kDa, and 4 times the volume of anhydrous ethanol was added to precipitate the polysaccharide. The product was placed in a refrigerator at 4°C overnight, and the precipitated flocs were centrifuged at 4000 r / min for 15 min. The precipitate was collected and vacuum freeze-dried to obtain Polygonatum sibiricum oligosaccharide.
[0025] Compared with the prior art, this method has the following advantages:
[0026] 1. In order to improve the current situation of low biological activity of Polygonatum sibiricum polysaccharides, we proposed a method for preparing Polygonatum sibiricum oligosaccharides with high biological activity by ionizing radiation degradation, which can quickly, controllably and accurately obtain low molecular weight Polygonatum sibiricum oligosaccharides with high biological activity.
[0027] 2. The radiation degradation process has mild reaction conditions and can be carried out at room temperature. The entire radiation degradation process does not require the addition of any substances toxic to the human body, and is safe and environmentally friendly.
[0028] 3. The radiation degradation extraction and sterilization process of Polygonatum sibiricum oligosaccharide can be completed simultaneously, saving costs. From a comprehensive and long-term perspective, the economic cost of preparing Polygonatum sibiricum oligosaccharide using the radiation degradation extraction process is lower.
[0029] like Figure 3 The figure shows the test of DPPH free radical scavenging ability. (a) The figure shows the verification of the stability of the DPPH free radical scavenging reaction system BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 The effect of radiation absorbed dose on the molecular weight of polygonatum sibiricum oligosaccharides (PSO) prepared by degradation of polygonatum sibiricum polysaccharide (PSP).
[0031] Figure 2 It is a test data chart of hydroxyl radical scavenging ability.
[0032] Figure 3 It is a test data chart of DPPH free radical scavenging ability.
[0033] Figure 4 This is a test data chart of ABTS free radical scavenging ability.
[0034] Figure 5 It is a graph of the test data of ferric reducing power (FRAP). DETAILED DESCRIPTION
[0035] The following are specific embodiments of the present invention, which further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.
[0036] Example 1: Weigh 1000g of Polygonatum sibiricum, wash and drain, cut into slices, freeze-dry for 1-2 days, crush, pass through a 30-mesh sieve, and obtain Polygonatum sibiricum powder. Take 600g of the crushed and sieved Polygonatum sibiricum powder, pack it in PE bags and seal it, and extract it with electron beam radiation. The irradiation dose is 0kGy and the dose rate is 20kGy / pass. The irradiated Polygonatum sibiricum powder is added with water with a solid-liquid ratio of 1:10 and refluxed for extraction once, each time for 1h, and filtered. The filtrate is concentrated under reduced pressure at 60°C, and after concentration, 4 times the volume of anhydrous ethanol solution is slowly added, and refrigerated at 4°C overnight. Centrifuge, discard the supernatant, wash the precipitate with 90% ethanol 3 times, freeze-dry, and obtain Polygonatum sibiricum crude polysaccharide. The obtained Polygonatum sibiricum crude polysaccharide is separated and purified using a DEAE-52 chromatography column, and then concentrated, precipitated with alcohol, centrifuged, freeze-dried, and dried to obtain Polygonatum sibiricum polysaccharide. Take an appropriate amount of Polygonatum sibiricum polysaccharide, pack it into a bag and seal it, then use a 1MeV electron accelerator to degrade it by radiation, select a dose rate of 20kGy / pass, and a total radiation absorption dose of 80kGy. After radiation, pass through an ultrafiltration system with a molecular cutoff of 200kDa, and concentrate to 1 / 5 volume by rotary evaporation under reduced pressure at 50°C, add 4 times the volume of anhydrous ethanol to precipitate the polysaccharide, place it in a refrigerator at 4°C and stand overnight, the precipitated flocculent precipitate is centrifuged at 4000r / min for 15min, collect the precipitate and vacuum freeze-dry it to obtain Polygonatum sibiricum oligosaccharide.
[0037] Example 2: Weigh 1000g of Polygonatum sibiricum, wash and drain, cut into thin slices, freeze-dry for 1-2 days, crush, pass through a 30-mesh sieve, and obtain Polygonatum sibiricum powder. Take 600g of the crushed and sieved Polygonatum sibiricum powder, pack it in PE bags and seal it, and extract it by electron beam radiation. The irradiation dose is 240kGy and the dose rate is 20kGy / pass. The irradiated Polygonatum sibiricum powder is added with water with a solid-liquid ratio of 1:20 and refluxed for 2 times, each time for 1.5h, and filtered. The filtrate is concentrated under reduced pressure at 60°C, and after concentration, 4 times the volume of anhydrous ethanol solution is slowly added, and refrigerated at 4°C overnight. Centrifuge, discard the supernatant, wash the precipitate with 90% ethanol 3 times, freeze-dry, and obtain Polygonatum sibiricum crude polysaccharide. The obtained Polygonatum sibiricum crude polysaccharide is separated and purified using a DEAE-52 chromatography column, and then concentrated, alcohol precipitated, centrifuged, freeze-dried, and dried to obtain Polygonatum sibiricum polysaccharide. Take an appropriate amount of Polygonatum sibiricum polysaccharide, pack it into a bag and seal it, then use a 1MeV electron accelerator to degrade it by radiation, select a dose rate of 20kGy / pass, and a total radiation absorption dose of 80kGy. After radiation, pass through an ultrafiltration system with a molecular cutoff of 200kDa, and concentrate it to 1 / 5 volume by rotary evaporation under reduced pressure at 50°C, add 4 times the volume of anhydrous ethanol to precipitate the polysaccharide, place it in a refrigerator at 4°C and let it stand overnight, the precipitated flocculent precipitate is centrifuged at 4000r / min for 15min, collect the precipitate and vacuum freeze-dry it to obtain Polygonatum sibiricum oligosaccharide.
[0038] Example 3: Weigh 1000g of Polygonatum sibiricum, wash and drain, cut into thin slices, cut the fibrous root sample into pieces, freeze-dry for 1-2 days, crush, and pass through a 30-mesh sieve to obtain Polygonatum sibiricum powder. Take 600g of the crushed and sieved Polygonatum sibiricum powder, pack it in PE bags and seal it, and extract it with electron beam radiation. The irradiation dose is 320kGy and the dose rate is 20kGy / pass. The irradiated Polygonatum sibiricum powder is added with water with a solid-liquid ratio of 1:30 and refluxed for 5 times, each time for 3h, and filtered. The filtrate is concentrated under reduced pressure at 60°C, and after concentration, 4 times the volume of anhydrous ethanol solution is slowly added, and refrigerated at 4°C overnight. Centrifuge, discard the supernatant, wash the precipitate with 90% ethanol 3 times, and freeze-dry to obtain Polygonatum sibiricum crude polysaccharide. The obtained Polygonatum sibiricum crude polysaccharide is separated and purified using a DEAE-52 chromatography column, and then concentrated, precipitated with alcohol, centrifuged, freeze-dried, and dried to obtain Polygonatum sibiricum polysaccharide. Take an appropriate amount of Polygonatum sibiricum polysaccharide, pack it into a bag and seal it, then use a 1MeV electron accelerator to degrade it by radiation, select a dose rate of 20kGy / pass, and a total radiation absorption dose of 80kGy. After radiation, pass through an ultrafiltration system with a molecular cutoff of 200kDa, and concentrate to 1 / 5 volume by rotary evaporation under reduced pressure at 50°C, add 4 times the volume of anhydrous ethanol to precipitate the polysaccharide, place it in a refrigerator at 4°C and stand overnight, the precipitated flocculent precipitate is centrifuged at 4000r / min for 15min, collect the precipitate and vacuum freeze-dry it to obtain Polygonatum sibiricum oligosaccharide.
[0039] Analyze with the attached drawings: Figure 1 As shown, it discloses the effect of radiation absorption dose on the molecular weight of Polygonatum sibiricum oligosaccharide (PSO) prepared by degradation of Polygonatum sibiricum polysaccharide (PSP). Figure (a) uses GPC to determine the molecular weight of PSO; Figure (b) is a quantitative analysis of molecular weight and peak area. It can be found in the figure that as the radiation absorption dose increases, the relative molecular mass of PSO decreases, but the molecular weight becomes more concentrated. The molecular weights are 674kDa (0kGy), 409kDa (80kGy), 322kDa (160kGy), 201kDa (240kGy), and 100kDa (320kGy), respectively.
[0040] like Figure 2 The figure shows the test of hydroxyl radical scavenging ability. (a) is the verification of the stability of the hydroxyl radical scavenging reaction system; (b) is the effect of different molecular weights and concentrations of PSO on the hydroxyl radical scavenging ability. It can be seen from the figure that: 1. The hydroxyl radical scavenging ability shows an increasing trend with the increase of PSO concentration, reaching the highest at 1.2 mg / mL, and then showing a downward trend. 2. At the same concentration, the hydroxyl radical scavenging ability also shows a trend of first increasing and then decreasing with the decrease of molecular weight. When the molecular weight is 201kDa, the hydroxyl radical scavenging ability is the strongest, which is 22.08%.
[0041] like Figure 3 The figure shows the test of DPPH free radical scavenging ability. (a) The figure shows the verification of the stability of the DPPH free radical scavenging reaction system; (b) The figure shows the effect of different molecular weights and concentrations of PSO on the DPPH free radical scavenging ability. It can be seen from the figure: First, the DPPH free radical scavenging ability shows an increasing trend with the increase of PSO concentration, reaching the highest at 1.5 mg / mL. Second, at the same concentration, the DPPH free radical scavenging ability also shows a trend of first increasing and then decreasing with the decrease of molecular weight. When the molecular weight is 201 kDa, the DPPH free radical scavenging ability is the strongest, which is 27.57%.
[0042] like Figure 4 The figure shows the test of ABTS free radical scavenging ability. (a) The figure shows the verification of the stability of the ABTS free radical scavenging reaction system; (b) The figure shows the effect of different molecular weights and concentrations of PSO on the ABTS free radical scavenging ability. It can be seen from the figure that: 1. The ABTS free radical scavenging ability shows an increasing trend with the increase of PSO concentration, reaching the highest at 1.5 mg / mL. 2. At the same concentration, the ABTS free radical scavenging ability also shows a trend of first increasing and then decreasing with the decrease of molecular weight. When the molecular weight is 201 kDa, the ABTS free radical scavenging ability is the strongest, which is 34.51%.
[0043] like Figure 5The figure shows the test of ferric iron reducing ability (FRAP). (a) The figure shows the verification of the stability of the ferric iron reducing ability test system; (b) The figure shows the effect of different molecular weights and concentrations of PSO on the ferric iron reducing ability test. It can be seen from the figure that: 1. The ferric iron reducing ability shows an increasing trend with the increase of the concentration of PSO, reaching the highest at 1.5 mg / mL. 2. At the same concentration, as the molecular weight decreases, the ability of PSO to reduce ferric iron also shows a trend of first increasing and then decreasing. When the molecular weight is 201 kDa, the reducing ability is the strongest, which is 17.69%.
[0044] In summary, firstly, ionizing radiation can efficiently degrade Polygonatum sibiricum polysaccharides and prepare Polygonatum sibiricum oligosaccharides with high biological activity. Secondly, in vitro antioxidant tests have shown that both PSP and PSO have good ROS scavenging ability, and the ROS scavenging ability of PSO is stronger than that of PSP. At the same time, the ROS scavenging ability of the same polysaccharide increases with the increase of polysaccharide concentration; at the same concentration, PSO with a molecular weight of 201kDa has the best ROS scavenging ability. The best hydroxyl radical scavenging rate is 22.08%, the DPPH radical scavenging rate is 27.57%, the best ABTS radical scavenging rate is 34.51%, and the best trivalent iron ion reduction rate is 17.69%.
[0045] The specific embodiments described herein are merely examples of the spirit of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in similar ways, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.
Claims
1. A method for preparing highly biologically active Polygonatum cyrtonema oligosaccharides by ionizing radiation degradation, characterized in that: The following steps are involved: 1) Weigh an appropriate amount of polygonatum, wash and slice, freeze-dry, crush and sieve to obtain polygonatum powder; 2) Put the crushed and sieved polygonatum powder into a PE bag and perform electron beam radiation extraction; 3) Add a certain amount of water to the irradiated polygonatum powder, reflux extract 1-5 times, each extraction time is 1-3h, the extraction temperature is 70-110℃, and filter; 4) The filtrate is concentrated under reduced pressure, precipitated with alcohol, and freeze-dried to obtain crude polygonatum polysaccharide; 5) Separating and purifying the obtained crude polygonatum polysaccharide using a DEAE-52 chromatography column, and then concentrating, ethanol precipitation, centrifuging, and freeze-drying to obtain polygonatum polysaccharide; 6) Take an appropriate amount of Polygonatum sibiricum polysaccharide, pack it into a bag and seal it, then use an electron accelerator to irradiate and degrade it. After irradiation, pass through an ultrafiltration system, rotary evaporation, alcohol precipitation, centrifugation, and freeze-drying to obtain Polygonatum sibiricum oligosaccharide.
2. The method for preparing a highly biologically active Polygonatum cyrtonema oligosaccharide by ionizing radiation degradation according to claim 1, characterized in that: In step 2), the dose rate is selected to be 20 kGy / pass and the radiation absorbed dose is 0-320 kGy.
3. The method for preparing a highly biologically active Polygonatum sibiricum oligosaccharide by ionizing radiation degradation according to claim 1, characterized in that: In step 3), water is added to the irradiated polygonatum powder to form a polygonatum powder aqueous solution with a solid-liquid ratio of 1:10-1:
30.
4. The method for preparing a highly biologically active polygonatum oligosaccharide by ionizing radiation degradation according to claim 1, characterized in that: In step 6), a 1 MeV electron accelerator is used to perform radiation degradation on the bagged and plastic-sealed Polygonatum sibiricum polysaccharide, the dose rate is selected to be 20 kGy / pass, and the total radiation absorption dose is 80-320 kGy.
5. The method for preparing a highly biologically active Polygonatum cyrtonema oligosaccharide by ionizing radiation degradation according to claim 1, characterized in that: Step 6) The average molecular weight of the obtained polygonatum oligosaccharide is about 200 kDa, and the molecular retention capacity of the ultrafiltration system selected for use is 200 kDa.
6. The method for preparing a highly biologically active Polygonatum cyrtonema oligosaccharide by ionizing radiation degradation according to claim 1, characterized in that: The alcohol precipitation process in step 6) is as follows: concentrate to 1 / 5 volume by rotary evaporation under reduced pressure at 50° C., add 4 times volume of anhydrous ethanol to precipitate polysaccharides, and place in a 4° C. refrigerator to stand overnight.