CN110551234A

CN110551234A - preparation method of pueraria polysaccharide and application of pueraria polysaccharide as growth promoter

Info

Publication number: CN110551234A
Application number: CN201911005700.9A
Authority: CN
Inventors: 童中华; 邵新月
Original assignee: University of Science and Technology of China USTC
Current assignee: University of Science and Technology of China USTC
Priority date: 2019-10-22
Filing date: 2019-10-22
Publication date: 2019-12-10

Abstract

the invention relates to the field of extraction of natural active substances, in particular to a preparation method of pueraria polysaccharide and application of pueraria polysaccharide as a growth promoter. The preparation method of the pueraria polysaccharide comprises the following steps: A) mixing the kudzu root powder with water according to the proportion of 1 g: 2-20 mL of the mixture is mixed, and ultrasonic extraction is carried out at 40-80 ℃; B) centrifuging the material liquid after ultrasonic extraction, wherein the centrifuged sediment and water are mixed according to the weight ratio of 1 g: 2-20 mL of the mixture is subjected to ultrasonic extraction at 40-80 ℃, and then centrifugation is performed; C) mixing the supernatants obtained after the two centrifugations in the step B), and carrying out reduced pressure concentration to obtain a concentrated solution; D) mixing the concentrated solution with ethanol according to a volume ratio of 1: 2-5, mixing, and carrying out alcohol precipitation; E) centrifuging the product solution after alcohol precipitation, and concentrating the obtained supernatant under reduced pressure to obtain a concentrated solution, namely the pueraria polysaccharide. The preparation method is simple to operate, and the yield of the pueraria polysaccharide is high.

Description

Preparation method of pueraria polysaccharide and application of pueraria polysaccharide as growth promoter

Technical Field

The invention relates to the field of extraction of natural active substances, in particular to a preparation method of pueraria polysaccharide and application of pueraria polysaccharide as a growth promoter.

Background

China has rich Chinese medicinal material resources, and in recent years, people pay great attention to the exploration of natural compounds of Chinese medicaments with anti-aging medicinal values. Pueraria lobata (Willd.) Ohwi, a dried root of Pueraria lobata Ohwi of Leguminosae, has antipyretic, eruption promoting, salivation promoting, thirst quenching, yang invigorating, and antidiarrheal effects. It is commonly used for treating fever due to exterior syndrome, strong pain of neck and back, measles without adequate eruption, fever with thirst, etc., and has significant medicinal and health-care values. Modern research has shown that natural polysaccharides have become a promising candidate source for controlling longevity and promoting healthy aging due to a wide range of pharmacological properties.

The traditional preparation method of the pueraria polysaccharide comprises the following steps: the organic solvent petroleum ether is used for repeated distillation reflux, absolute ethyl alcohol precipitation and acetone washing, a reflux device needs to be built, the preparation steps are complex, the yield is low, the petroleum ether has volatility and strong irritation, and the petroleum ether has certain harm to human bodies and the environment.

Disclosure of Invention

In view of the above, the technical problem to be solved by the present invention is to provide a preparation method of pueraria polysaccharide, which is simple and has a high yield.

The invention provides a preparation method of pueraria polysaccharide, which comprises the following steps:

A) mixing the kudzu root powder with water according to the proportion of 1 g: 2-20 mL of the mixture is mixed, and ultrasonic extraction is carried out at 40-80 ℃;

B) centrifuging the material liquid after ultrasonic extraction, wherein the centrifuged sediment and water are mixed according to the weight ratio of 1 g: 2-20 mL of the mixture is subjected to ultrasonic extraction at 40-80 ℃, and then centrifugation is performed;

C) Mixing the supernatants obtained after the two centrifugations in the step B), and carrying out reduced pressure concentration to obtain a concentrated solution;

D) mixing the concentrated solution with ethanol according to a volume ratio of 1: 2-5, mixing, and carrying out alcohol precipitation;

E) Centrifuging the product solution after alcohol precipitation, and concentrating the obtained supernatant under reduced pressure to obtain a concentrated solution, namely the pueraria polysaccharide.

preferably, in the step A) and the step B), the ultrasonic extraction time is 0.5-1 h.

Preferably, in the step B), the rotation speed of the centrifugation is 2900-3100 r/min, and the centrifugation time is 15-18 min.

Preferably, in the step C), the temperature of the reduced pressure concentration is 60-80 ℃.

preferably, in step D), the volume fraction of ethanol is 95%.

Preferably, in the step E), the alcohol precipitation time is 12-15 h.

preferably, in the step E), the rotating speed of the centrifugation is 3000r/min, and the time of the centrifugation is 10-15 min.

Preferably, in the step E), the temperature of the reduced pressure concentration is 55-60 ℃.

The invention also provides application of the pueraria polysaccharide prepared by the preparation method as a growth promoter.

the invention provides a preparation method of pueraria polysaccharide, which comprises the following steps: A) mixing the kudzu root powder with water according to the proportion of 1 g: 2-20 mL of the mixture is mixed, and ultrasonic extraction is carried out at 40-80 ℃; B) centrifuging the material liquid after ultrasonic extraction, wherein the centrifuged sediment and water are mixed according to the weight ratio of 1 g: 2-20 mL of the mixture is subjected to ultrasonic extraction at 40-80 ℃, and then centrifugation is performed; C) mixing the supernatants obtained after the two centrifugations in the step B), and carrying out reduced pressure concentration to obtain a concentrated solution; D) mixing the concentrated solution with ethanol according to a volume ratio of 1: 2-5, mixing, and carrying out alcohol precipitation; E) centrifuging the product solution after alcohol precipitation, and concentrating the obtained supernatant under reduced pressure to obtain a concentrated solution, namely the pueraria polysaccharide. The preparation method of the pueraria polysaccharide provided by the invention is simple to operate, mild in preparation conditions, short in period, low in cost and high in yield of the pueraria polysaccharide.

The experimental result shows that the preparation method of the pueraria polysaccharide provided by the invention can obtain higher yield, and the yield of the pueraria polysaccharide is higher than 8%, even obviously exceeds 25%.

The invention also provides application of the pueraria polysaccharide prepared by the preparation method as a growth promoter. The applicant creatively discovers that the pueraria polysaccharide can improve the heat stress resistance of the caenorhabditis elegans, further promote the growth and development of the caenorhabditis elegans, increase the body length of the model organism caenorhabditis elegans and promote the growth and development of human bodies.

experimental results show that the growth of the caenorhabditis elegans under heat stress is obviously increased after the caenorhabditis elegans is treated by the pueraria polysaccharide solutions with the concentrations of 20mg/L, 40mg/L, 60mg/L, 80mg/L and 100mg/L respectively.

drawings

FIG. 1 is a standard curve for glucose in polysaccharide content determination;

FIG. 2 is a graph showing the body length change of nematodes subjected to heat stress after treatment with different concentrations of pueraria polysaccharide solutions;

FIG. 3 is a graph showing the effect of heat stress on the ROS content in C.elegans treated with different concentrations of pueraria polysaccharide solutions;

FIG. 4 is a graph showing the effect of heat stress on the MDA content in C.elegans treated with different concentrations of pueraria polysaccharide solutions;

FIG. 5 is a graph showing the effect of heat stress on the SOD content in C.elegans treated with different concentrations of pueraria polysaccharide solutions.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the following embodiments of the present invention, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention firstly mixes the kudzu root powder and water according to the proportion of 1 g: 2-20 mL of the mixture is mixed and subjected to ultrasonic extraction at 40-80 ℃.

In the invention, the using amount ratio of the kudzu root powder to water is 1 g: 2-20 mL. In certain embodiments of the present invention, the ratio of the amount of pueraria powder to water is 1 g: 5mL, 1 g: 10mL, 1 g: 15mL or 1 g: 20 mL.

The source of the kudzu root powder is not particularly limited, and the kudzu root powder can be generally sold in the market.

Mixing radix Puerariae powder with water, and ultrasonic extracting the mixed solution. The temperature of ultrasonic extraction is 40-80 ℃. In certain embodiments of the invention, the temperature of the ultrasonic extraction is 40 ℃, 60 ℃ or 80 ℃. In some embodiments of the invention, the ultrasonic power of the ultrasonic extraction is 400-800W. In certain embodiments, the ultrasound extracted ultrasound power is 400W. In some embodiments of the invention, the time for ultrasonic extraction is 0.5-1.5 h. In certain embodiments of the invention, the time of the ultrasonic extraction is 0.5h, 1h, or 1.5 h. The ultrasonic energy promotes the wall breaking or deformation of plant tissues, so that the effective components of the traditional Chinese medicine are extracted more fully.

And after the ultrasonic extraction is finished, centrifuging the material liquid subjected to the ultrasonic extraction. In some embodiments of the invention, the rotation speed of the centrifugation is 2900-3100 r/min. In certain embodiments, the rotational speed of the centrifuge is 3000 r/min. In some embodiments of the invention, the centrifugation time is 15-18 min. In certain embodiments, the time for centrifugation is 15 min.

After centrifugation, the centrifuged sediment was mixed with water in a ratio of 1 g: 2-20 mL of the mixture is mixed and subjected to ultrasonic extraction at 40-80 ℃.

In the invention, the dosage ratio of the centrifuged sediment to water is 1 g: 2-20 mL. In certain embodiments of the invention, the ratio of sediment to water after centrifugation is 1 g: 5mL, 1 g: 10mL, 1 g: 15mL or 1 g: 20 mL.

And mixing the centrifuged sediment with water to obtain a mixed solution, and performing ultrasonic extraction on the mixed solution. The temperature of ultrasonic extraction is 40-80 ℃. In certain embodiments of the invention, the temperature of the ultrasonic extraction is 40 ℃, 60 ℃ or 80 ℃. In some embodiments of the invention, the ultrasonic power of the ultrasonic extraction is 400-800W. In certain embodiments, the ultrasound extracted ultrasound power is 400W. In some embodiments of the invention, the time for ultrasonic extraction is 0.5-1.5 h. In certain embodiments of the invention, the time of the ultrasonic extraction is 0.5h, 1h, or 1.5 h. The ultrasonic energy promotes the wall breaking or deformation of plant tissues, so that the effective components of the traditional Chinese medicine are extracted more fully.

mixing the supernatants, and concentrating under reduced pressure to obtain concentrated solution. In some embodiments of the invention, the temperature of the reduced pressure concentration is 60-80 ℃. In certain embodiments, the temperature of the reduced pressure concentration is 60 ℃. In some embodiments of the invention, the time for the concentration under reduced pressure is 20-30 min. In certain embodiments of the invention, the time for the concentration under reduced pressure is 25 min. In certain embodiments of the invention, the method of concentrating under reduced pressure is rotary evaporation.

after a concentrated solution is obtained, mixing the concentrated solution with ethanol according to a volume ratio of 1: 2-5, and carrying out alcohol precipitation.

The volume ratio of the concentrated solution to the ethanol is 1: 2 to 5. In certain embodiments of the invention, the volume ratio of the concentrate to ethanol is 1: 4. in certain embodiments of the invention, the volume fraction of ethanol is 95%.

In some embodiments of the invention, the time after alcohol precipitation is 12-15 hours. In certain embodiments, the time after alcohol precipitation is 12 h.

And after the alcohol precipitation is finished, centrifuging the product solution after the alcohol precipitation, and concentrating the obtained supernatant under reduced pressure to obtain a concentrated solution, namely the pueraria polysaccharide.

in some embodiments of the invention, the rotation speed of the centrifugation of the product solution after alcohol precipitation is 3000r/min, and the centrifugation time is 10-15 min. In certain embodiments of the invention, the time for the centrifugation is 12 min.

In some embodiments of the invention, the temperature of the obtained supernatant after vacuum concentration is 55-60 ℃. In certain embodiments, the resulting filtrate is concentrated under reduced pressure at a temperature of 60 ℃. In some embodiments of the invention, the time for concentrating the obtained filtrate under reduced pressure is 15-20 min. In certain embodiments of the invention, the resulting filtrate is concentrated under reduced pressure for 18 min.

The preparation method of the pueraria polysaccharide provided by the invention is simple to operate, mild in preparation conditions, short in period, low in cost and high in yield of the pueraria polysaccharide.

The invention also provides application of the pueraria polysaccharide prepared by the preparation method as a growth promoter. The applicant creatively discovers that the pueraria polysaccharide can improve the heat stress resistance of the caenorhabditis elegans, further promote the growth and development of the caenorhabditis elegans, increase the body length of the model organism caenorhabditis elegans and promote the growth and development of human bodies. Thus, the applicant claims the use of said pueraria polysaccharides as growth promoters.

In the present invention, the source of the raw material is not particularly limited, and may be generally commercially available.

in order to further illustrate the present invention, the following examples are provided to describe the preparation method of pueraria polysaccharide and the application of pueraria polysaccharide as growth promoter in detail, but they should not be construed as limiting the scope of the present invention.

Example 1

1. Weighing 2g of radix puerariae powder in a 50mL conical flask, adding 10mL of distilled water, performing ultrasonic extraction at 40 ℃ for 0.5h, centrifuging at the rotating speed of 3000r/min for 15min, and mixing the centrifuged sediment and water according to the weight ratio of 1 g: 5mL of the mixture is mixed and extracted by ultrasonic for 0.5h at the temperature of 40 ℃; the ultrasonic power of the two ultrasonic extractions is 400W;

2. mixing the supernatants obtained in step 1 after twice centrifugation, and performing rotary evaporation at 60 ℃ for 25min to obtain a concentrated solution;

3. Mixing the concentrated solution obtained in the step 2 with ethanol (95% by volume) according to a volume ratio of 1: 4, mixing and carrying out alcohol precipitation; the alcohol precipitation time is 12 hours;

4. after the alcohol precipitation is finished, centrifuging the product solution after the alcohol precipitation for 12min at the rotating speed of 3000r/min, and concentrating the obtained supernatant at 60 ℃ under reduced pressure for 18min to obtain a concentrated solution, namely the pueraria polysaccharide.

Example 2

1. Weighing 2g of radix puerariae powder in a 50mL conical flask, adding 20mL of distilled water, performing ultrasonic extraction at 40 ℃ for 0.5h, centrifuging at the rotating speed of 3000r/min for 15min, and mixing the centrifuged sediment and water according to the weight ratio of 1 g: mixing 10mL of the mixture, and performing ultrasonic extraction at 40 ℃ for 0.5 h; the ultrasonic power of the two ultrasonic extractions is 400W;

example 3

1. Weighing 2g of radix puerariae powder in a 50mL conical flask, adding 30mL of distilled water, performing ultrasonic extraction at 40 ℃ for 0.5h, centrifuging at the rotating speed of 3000r/min for 15min, and mixing the centrifuged sediment and water according to the weight ratio of 1 g: mixing 15mL of the mixture, and performing ultrasonic extraction at 40 ℃ for 0.5 h; the ultrasonic power of the two ultrasonic extractions is 400W;

Example 4

1. Weighing 2g of radix puerariae powder in a 50mL conical flask, adding 40mL of distilled water, performing ultrasonic extraction at 60 ℃ for 0.5h, centrifuging at the rotating speed of 3000r/min for 15min, and mixing the centrifuged sediment and water according to the weight ratio of 1 g: mixing 20mL of the mixture, and performing ultrasonic extraction at 60 ℃ for 0.5 h; the ultrasonic power of the two ultrasonic extractions is 400W;

example 5

1. Weighing 2g of radix puerariae powder in a 50mL conical flask, adding 40mL of distilled water, performing ultrasonic extraction at 80 ℃ for 0.5h, centrifuging at the rotating speed of 3000r/min for 15min, and mixing the centrifuged sediment and water according to the weight ratio of 1 g: mixing 20mL of the mixture, and performing ultrasonic extraction at 80 ℃ for 0.5 h; the ultrasonic power of the two ultrasonic extractions is 400W;

Example 6

1. Weighing 2g of kudzu root powder in a 50mL conical flask, adding 40mL of distilled water, performing ultrasonic extraction at 80 ℃ for 1h, centrifuging at the rotating speed of 3000r/min for 15min, and mixing the centrifuged sediment and water according to the weight ratio of 1 g: mixing 20mL of the mixture, and performing ultrasonic extraction at 80 ℃ for 1 h; the ultrasonic power of the two ultrasonic extractions is 400W;

Example 7

1. Weighing 2g of radix puerariae powder in a 50mL conical flask, adding 40mL of distilled water, performing ultrasonic extraction at 80 ℃ for 1.5h, centrifuging at the rotating speed of 3000r/min for 15min, and mixing the centrifuged sediment and water according to the weight ratio of 1 g: mixing 20mL of the mixture, and performing ultrasonic extraction at 80 ℃ for 1.5 h; the ultrasonic power of the two ultrasonic extractions is 400W;

Example 8

Detecting the extraction rate of the pueraria polysaccharide of the embodiment 1-7:

Respectively diluting the concentrated solution obtained in the embodiment 1-7 with distilled water to obtain 7 groups of samples to be detected;

Preparing a standard curve and detecting a sample:

(1) preparing 300mL of concentrated sulfuric acid with volume fraction of 95%, adding 0.2g of anthrone reagent into the concentrated sulfuric acid, and dissolving;

(2) Weighing glucose standard substances, preparing glucose solutions with different concentration gradients of 20mg/L, 40mg/L, 60mg/L, 80mg/L and 100mg/L respectively, and using distilled water as blank control;

(3) after standard samples with different concentrations are prepared, respectively adding 2mL of standard samples with different concentrations and 7 groups of samples to be detected into different digestion tubes, adding 3 parallel samples, adding 5mL of anthrone-concentrated sulfuric acid reagent into each digestion tube, boiling in a water bath for 10min, and cooling with cold water;

(4) After the standard sample and the sample to be measured are cooled, the absorbance at 620nm is measured by an ultraviolet spectrophotometer.

The glucose concentration was plotted on the abscissa and the absorbance on the ordinate, and a standard curve was obtained by linear regression, as shown in FIG. 1. FIG. 1 is a standard curve of glucose in polysaccharide content measurement. The extraction rate of pueraria polysaccharide was calculated from the standard curve as shown in table 1.

TABLE 1 extraction rates of pueraria polysaccharide of examples 1 to 7

Serial number	Solid-liquid ratio (g: mL)	ultrasonic temperature (. degree. C.)	Ultrasonic time (h)	Extraction ratio (%)
					example 1	1:5	40	0.5	8.02
Example 2	1:10	40	0.5	9.85
					Example 3	1:20	40	0.5	12.3
Example 4	1:20	60	0.5	13.8
					Example 5	1:20	80	0.5	14.9
Example 6	1:20	80	1	16.2
					Example 7	1:20	80	1.5	27.7

as can be seen from Table 1, the preparation method of pueraria polysaccharide provided by the invention can obtain higher yield, and the yield of pueraria polysaccharide is higher than 8%, even obviously exceeds 25%. Compared with the traditional preparation method, the extraction rate of the pueraria polysaccharide is greatly improved.

example 9

The caenorhabditis elegans used in the experiment was the wild type Bristol N2 strain, provided by the nematode genetic center (CGC). Unless otherwise specified, e.coli OP50 was used as nematode food, which was also provided by the nematode genetic center.

measurement of body length of caenorhabditis elegans:

the pueraria polysaccharide prepared in the example 7 is prepared into pueraria polysaccharide solutions with the concentration of 20mg/L, 40mg/L, 60mg/L, 80mg/L and 100mg/L respectively.

The synchronized caenorhabditis elegans were transferred to NGM solid plates containing appropriate amounts of food OP50 after liquid culture to L1. Then, the cells were cultured under optimum culture conditions at 20 ℃ until the L4 stage, and the L4 stage nematodes were washed from the solid plates with M9 buffer solution (nematode liquid buffer salt), collected in a centrifuge tube, and washed twice with M9 buffer solution.

Polysaccharide solutions (0, 20mg/L, 40mg/L, 60mg/L, 80mg/L, 100mg/L) were treated in 24-well plates at different concentrations, 3 wells in parallel, at least 30. + -.2 nematodes per concentration. Culturing at 20 deg.C under optimum condition for 24 hr, transferring the cultured nematodes to 37 deg.C constant temperature incubator for 3 hr, performing heat treatment for 3 hr, and transferring to 20 deg.C constant temperature incubator for 24 hr.

then, the nematodes treated with the same polysaccharide concentration were collected in the same centrifuge tube, washed 3 times with PBS solution, and then left to settle into the bottom of the centrifuge tube. Taking out the liquid by using a pipette, leaving about 100 mu L of the nematode liquid, carrying out water bath treatment in a prepared water bath kettle at 60 ℃ for 10min, immediately taking out the nematode liquid, adding the nematode-containing liquid to a 3.5cm NGM plate with the surface filled with PBS buffer solution (pH 7.45) for cooling, connecting a body type microscope to a computer, photographing the stiff nematodes by using Toupview software, processing pictures by using Image J software to obtain nematode body length data, wherein the number of nematodes at each concentration is at least 20, and carrying out the experiment independently for 3 times.

the test results are shown in figure 2, and figure 2 is a body length change diagram of the nematodes subjected to heat stress after being treated by the pueraria polysaccharide solutions with different concentrations. As shown in FIG. 2, the growth of caenorhabditis elegans under heat stress was significantly increased after treatment with 20mg/L, 40mg/L, 60mg/L, 80mg/L, and 100mg/L pueraria polysaccharide solutions. After the water bath treatment is carried out in a water bath kettle at the temperature of 60 ℃ for 10min, the length of the nematode can be increased by 0.073mm through 20mg/L of pueraria polysaccharide solution, the length of the nematode can be increased by 0.093mm through 40mg/L of pueraria polysaccharide solution, the length of the nematode can be increased by 0.097mm through 60mg/L of pueraria polysaccharide solution, the length of the nematode can be increased by 0.099mm through 80mg/L of pueraria polysaccharide solution, and the length of the nematode can be increased by 0.114mm through 100mg/L of pueraria polysaccharide solution.

example 10

Determination of ROS (reactive oxygen species), MDA (lipid oxidation), SOD (superoxide dismutase) in caenorhabditis elegans:

Then, the nematodes treated with the same polysaccharide concentration are collected in the same centrifugal tube, washed for 3 times by PBS solution, ultrasonically cracked by an ultrasonic cell disruption instrument, centrifuged by a centrifuge capable of cooling after the cracking is finished, supernatant is obtained, the ROS, MDA and SOD are measured according to the instruction of a corresponding detection kit (ROS detection kit, MDA detection kit or SOD detection kit) produced in Biyunyan, and the protein concentration is measured by a BCA protein quantification method and calculated.

The test results are shown in fig. 3, 4 and 5. FIG. 3 is a graph showing the effect of heat stress on the ROS content in C.elegans treated with different concentrations of pueraria polysaccharide solutions. FIG. 4 is a graph showing the effect of heat stress on the MDA content in C.elegans treated with different concentrations of pueraria polysaccharide solutions. FIG. 5 is a graph showing the effect of heat stress on the SOD content in C.elegans treated with different concentrations of pueraria polysaccharide solutions.

As can be seen in FIG. 3, 20mg/L, 40mg/L, 60mg/L, 80mg/L, 100mg/L of pueraria polysaccharide was able to reduce the level of ROS in nematodes relative to the control group. 20mg/L, 40mg/L, 60mg/L, 80mg/L and 100mg/L of the pueraria polysaccharide solution reduce the ROS content in the nematode by 8.8%, 62.6%, 16.8%, 34.5% and 70.3% respectively.

As can be seen from FIG. 4, 20mg/L, 40mg/L, 60mg/L, 80mg/L, 100mg/L of pueraria polysaccharide can reduce the amount of MDA in the nematode relative to the control group. 20mg/L, 40mg/L, 60mg/L, 80mg/L and 100mg/L of pueraria polysaccharide solution reduce the content of MDA in nematode by 1.01 mu m/mgproteins, 1.14 mu m/mgproteins, 1.32 mu m/mgproteins, 0.67 mu m/mgproteins and 0.61 mu m/mgproteins respectively.

As can be seen from FIG. 5, 20mg/L, 40mg/L, 60mg/L, 80mg/L, 100mg/L pueraria polysaccharide can increase the SOD activity in nematodes, relative to the control group. The activity of 20mg/L, 40mg/L, 60mg/L, 80mg/L and 100mg/L pueraria polysaccharide solution on SOD in nematode bodies is respectively improved by 22.27U/mgprot, 18.69U/mgprot, 18.05U/mgprot, 17.84U/mgprot and 14.55U/mgprot.

The results show that the pueraria polysaccharide can improve the body length of the caenorhabditis elegans under the condition of heat stress by reducing the ROS content and the MDA content in the caenorhabditis elegans and improving the SOD content in the caenorhabditis elegans, and can promote the growth and development of human bodies.

the previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. a preparation method of pueraria polysaccharide comprises the following steps:

2. The preparation method of claim 1, wherein in the step A) and the step B), the ultrasonic extraction time is 0.5-1 h.

3. The method according to claim 1, wherein in step B), the rotation speed of the centrifugation is 2900 to 3100r/min, and the time of the centrifugation is 15 to 18 min.

4. The method according to claim 1, wherein the temperature of the vacuum concentration in step C) is 60 to 80 ℃.

5. The method according to claim 1, wherein the ethanol is present in the amount of 95% by volume in step D).

6. The preparation method according to claim 1, wherein in the step E), the alcohol precipitation time is 12-15 h.

7. The preparation method according to claim 1, wherein in the step E), the rotation speed of the centrifugation is 3000r/min, and the centrifugation time is 10-15 min.

8. The method according to claim 1, wherein the temperature of the vacuum concentration in step E) is 55 to 60 ℃.

9. Use of pueraria polysaccharide prepared by the method of any one of claims 1 to 8 as a growth promoter.