CN106977559A - A kind of method of separating-purifying punicalagins and gallic acid simultaneously from granatum - Google Patents

Abstract

The invention provides a method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel, comprising the steps of: raw material pretreatment, extraction, concentration, water precipitation decolorization, resin adsorption, resin analysis, analysis solution extraction, and crystallization. The above method realizes the simultaneous separation and purification of punicalagin and gallic acid from pomegranate peel, and the content of separated and purified punicalagin is greater than 98%, the content of gallic acid is greater than 96%, the recovery rate of punicalagin is greater than 71%, and the content of gallaginic acid is greater than 96%. Acid recovery was greater than 68%.

Description

A method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel

technical field

The invention relates to the pomegranate peel extraction technology, in particular to a method for simultaneously extracting and separating punicalagin and gallic acid from the pomegranate peel.

Background technique

Pomegranate (Punica granatum L.) is a deciduous shrub or small tree plant of the genus Pomegranate in the Pomegranate family. my country has a cultivation history of nearly 2000 years. Compendium of Materia Medica records that pomegranate has the effect of "antidiarrheal dysentery, bleeding, anal prolapse, and metrorrhagia", and the pomegranate peel is rich in active ingredients such as gallic acid and punicalagin. Picalagin, molecular formula C ₄₈ H ₂₈ O ₃₀ , molecular weight 1084.72, punicalagin has various pharmacological effects such as anti-oxidation, anti-cancer, antibacterial, anti-viral, anti-inflammatory, etc. In addition, punicalagin is absorbed by the human body, Under the action of human enzymes, it can be decomposed into ellagic acid. Ellagic acid has excellent antioxidant properties and has been used as a food antioxidant and can be used in cosmetics. The molecular formula of gallic acid is C ₇ H ₆ O ₅ , and the molecular weight is 170.12. Gallic acid has various biological activities such as anti-inflammation, anti-mutation, anti-oxidation, and anti-free radical. At the same time, gallic acid has anti-tumor, liver protection, and inhibition of endothelial relaxation. effect.

As a traditional Chinese herbal medicine with the same origin as medicine and food, pomegranate has been paid more and more attention to its medicinal and edible value. The pomegranate peel, as a by-product of fruit pomegranate processing, is currently used as a fertilizer in most cases. If the active substances in the pomegranate peel can be effectively utilized, the added value of the product will be greatly improved.

At present, there are existing patents and documents related to the separation and purification of punicalagin or gallic acid from pomegranate peel, such as the patent "ZL200710106039.1 A kind of pomegranate peel extract and its preparation method", which discloses using pomegranate peel as raw material, The pomegranate peel extract with a punicalagin content of more than 40% is obtained through the processes of extraction with a low-carbon alcohol organic solvent, concentration, column chromatography, and drying. Patent "ZL201010510836.8 A method for extracting punicalagin from pomegranate peel", the invention discloses the use of pomegranate peel as raw material, extraction with ethanol, membrane separation means and activated carbon adsorption separation to obtain punicalagin product; patent "ZL201010531940. 5 A method for preparing punicalagin and ellagic acid from pomegranate peel", the invention discloses that the purity of punicalagin is more than 40%, and the tanned Products with a purity of flower acid above 90%; Master’s research paper “Purification of Punicalagin in Pomegranate Peel and Study on Inhibition of Tyrosinase Activity, Author: Cui Yanna” used dry column method, high-speed countercurrent chromatography, gel LH- 20 chromatographic methods were used to prepare punicalagin with a purity of 96.21% from 40% crude punicalagin. According to the patent search and domestic and foreign papers review, there is no method and report for simultaneously extracting punicalagin and gallic acid from pomegranate peel raw materials. Therefore, in order to maximize the raw material value of pomegranate peel, it is necessary to develop a simultaneous Process for separating and purifying punicalagin and gallic acid from pomegranate peel.

Contents of the invention

In view of the above situation, it is necessary to provide a method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel, so as to realize the simultaneous separation and purification of punicalagin and gallic acid.

The invention provides a method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel, comprising the steps of: raw material pretreatment: taking the raw material of pomegranate peel for crushing; extraction: under a certain temperature condition, using saturated Ultrasonic reflux extraction of crushed pomegranate peels with alcohol to obtain pomegranate peel extracts; concentration: concentrate the pomegranate peel extracts to obtain pomegranate peel concentrates, and recover the organic solvent at the same time; water precipitation decolorization: add appropriate amount of pomegranate peel concentrate water, flocculant, and decolorizing agent for water precipitation, decolorization, water precipitation, decolorization after a period of time to filter to obtain the filtrate; resin adsorption: the filtrate is adsorbed by the resin; resin analysis: wash the resin with deionized water, and then successively use low concentration Organic alcohol and high-concentration organic alcohol analysis resin, respectively collect low-concentration organic alcohol analysis solution A and high-concentration organic alcohol analysis solution B; analysis solution extraction, crystallization: concentrate analysis solution A, extract the concentrated analysis solution A with an appropriate amount of ethyl acetate , collect the lower layer extract and concentrate, crystallize, dissolve, recrystallize at a certain temperature, dry and recrystallize to obtain the separated and purified product a; at the same time, concentrate the analysis solution B, extract the concentrated analysis solution B with an appropriate amount of chloroform, and collect the lower layer extract And concentrate, crystallize, dissolve, recrystallize at a certain temperature, dry and recrystallize to obtain the isolated and purified product b; wherein, product a is punicalagin with a content greater than 98%, and product b is gallic acid with a content greater than 96%.

Further, in the extraction step, the saturated alcohol with less than 4 carbon atoms is ethanol or methanol, the concentration of ethanol or methanol is between 50% and 80% (V/V), and it needs to be soaked for 0.5 hours to 2 hours before ultrasonic reflux extraction , the extraction temperature is 60°C-80°C, the ultrasonic reflux extraction time is 1 hour-2 hours, and the ultrasonic power is 3KW-30KW.

Further, in the concentration step, the pomegranate peel extract is concentrated in a vacuum, and the relative density of the pomegranate peel concentrate obtained by the vacuum concentration is 1.1 g/cm ³ -1.3 g/cm ³ .

Further, in the water precipitation and decolorization step, the added water is deionized water, the volume of the added water is 10 to 15 times the volume of the pomegranate peel concentrate, and the weight of the flocculant added is 0.2% of the weight of the used pomegranate peel raw material ～0.5%, the weight of adding decolorizing agent is 2%～5% of the raw material weight of pomegranate peel used, and the water sinking and decolorizing time are 8～12 hours.

Further, the filtration in the water precipitation and decolorization step includes pressure filtration and ultrafiltration. First, a plate and frame filter is used for pressure filtration to filter out the flocculant and decolorizing agent, and then an ultrafiltration membrane with a molecular weight cut-off greater than or equal to 30,000 Dal is used. Ultrafiltration was performed to obtain a filtrate.

Further, the ultrafiltration membrane is a vacuum fiber membrane.

Further, in the resin adsorption step, the resin is a polar macroporous adsorption resin, and the polar macroporous adsorption resin is LAS-7 polar resin or HPD500 polar resin.

Further, in the resin analysis step, the organic alcohol is ethanol or methanol, the concentration of the low-concentration organic alcohol is 15% to 30% (V/V), and the concentration of the high-concentration organic alcohol is 50% %～70% (V/V).

Further, in the analysis solution extraction and crystallization steps, the extraction times of the analysis solution A concentrated by ethyl acetate extraction and the analysis solution B concentrated by chloroform extraction are 2 to 3 times respectively.

Further, the control conditions for the primary crystallization and recrystallization steps of the analytical solution extraction and crystallization steps are standing at 4°C to 8°C for 12 hours to 18 hours for crystallization.

The beneficial effect brought by the technical solution of the embodiment of the present invention is: the above method realizes the simultaneous separation and purification of punicalagin and gallic acid from pomegranate peel, and the content of separated and purified punicalagin is greater than 98%, and the content of gallic acid is greater than 96%, the recovery rate of punicalagin was greater than 71%, and the recovery rate of gallic acid was greater than 68%.

Description of drawings

Fig. 1 is the flowchart of the method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel of the present invention.

detailed description

In order to make the purpose, technical solution and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings.

Fig. 1 is a flowchart of the method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel of the present invention, specifically, please refer to Fig. 1, the method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel of the present invention method, comprising the steps of:

S201: Raw material pretreatment: take the pomegranate peel raw material and grind it.

S202: Extraction: under a certain temperature condition, the crushed pomegranate peel is subjected to ultrasonic reflux extraction with a saturated alcohol with less than 4 carbon atoms (C _n H _2n+1 OH, n<4), so as to obtain a pomegranate peel extract.

S203: concentrating: concentrating the pomegranate peel extract to obtain a pomegranate peel concentrate, and recovering the organic solvent at the same time.

S204: decolorization by water precipitation: Add appropriate amount of water, flocculant, and decolorant to the pomegranate peel concentrate to carry out water precipitation and decolorization, and filter to obtain a filtrate after water precipitation and decolorization for a period of time.

S205: resin adsorption: the filtrate is adsorbed by the resin.

S206: Resin analysis: washing the resin with deionized water, and then successively analyzing the resin with low-concentration organic alcohol and high-concentration organic alcohol, and collecting low-concentration organic alcohol analysis solution A and high-concentration organic alcohol analysis solution B respectively.

S207: Analysis solution extraction and crystallization: Concentrate the analysis solution A, extract the concentrated analysis solution A with an appropriate amount of ethyl acetate, collect the lower layer extract and concentrate, crystallize, dissolve, recrystallize at a certain temperature, dry and recrystallize to obtain separation and purification Product a; at the same time, concentrate the analytical solution B, extract the concentrated analytical solution B with an appropriate amount of chloroform, collect the lower layer extract and concentrate, crystallize, dissolve, recrystallize at a certain temperature, dry and recrystallize to obtain the isolated and purified product b.

S208: Product detection and content determination: use HPLC (High Performance Liquid Chromatography, High Performance Liquid Chromatography) to detect the composition and content of product a and product b, and calculate the recovery rate of active substances in product a and product b.

In the raw material pretreatment step of S201, dried pomegranate peels are used as the raw material, and crushed by a pulverizer to facilitate subsequent extraction more efficiently. The raw material of the pomegranate peel comes from Mengzi, Yunnan. Among the raw materials of the pomegranate peel, the water content of the raw pomegranate peel is less than 10%, the content of punicalagin is higher than 5.0%, and the content of gallic acid is higher than 1.0%.

In the S202 extraction step, the saturated alcohol with carbon atoms below 4 is preferably ethanol or methanol, the concentration of ethanol or methanol is between 50% and 80% (V/V), and it needs to be soaked for 0.5 hours to 2 hours before ultrasonic reflux extraction. The ultrasonic reflux extraction temperature is 60°C-80°C, the ultrasonic reflux extraction time is 1 hour-2 hours, and the ultrasonic power is 3KW-30KW.

In the step of concentrating in S203, the pomegranate peel extract is concentrated by vacuum concentration, and at the same time organic solvents such as saturated alcohols with carbon atoms below 4 are recovered. The concentrated solution obtained by vacuum concentration has a relative density of 1.1g/cm ³ -1.3g/cm ³ .

In the step S204 of decolorizing by water precipitation, the added water is deionized water, and the volume of the added water is 10 to 15 times the volume of the pomegranate peel concentrate. The weight of the flocculant added is 0.2%-0.5% of the weight of the pomegranate peel raw material used in the extraction step, and the flocculant can be chitin, polyacrylic acid, polyacrylic acid salt, polyacrylamide, etc., but not limited thereto. The weight of the added decolorizing agent is 2% to 5% of the weight of the pomegranate peel raw material used in the extraction step, and the decolorizing agent generally refers to a physical decolorizing agent such as activated carbon. Water sinking and decolorization time is 8-12 hours. Filtration includes pressure filtration and ultrafiltration. Generally, a plate and frame filter is used for pressure filtration to filter out flocculants and decolorizers, and then an ultrafiltration membrane with a certain molecular weight cut-off is used for ultrafiltration to obtain a filtrate. The molecular weight cut-off of the ultrafiltration membrane is greater than or equal to 30000Dal, and the ultrafiltration membrane is preferably a vacuum fiber membrane.

In the S205 resin adsorption step, the resin used is a polar macroporous adsorption resin, preferably LAS-7 polar resin or HPD500 polar resin.

In the S206 resin analysis step, wash the resin with a certain amount of deionized water, then use a certain amount of low-concentration organic alcohol to analyze the resin, collect its corresponding analysis solution A ₁ , and then wash the resin with a certain amount of deionized water, At the same time, collect the washing solution A ₂ of this part of deionized water, combine the analysis solution A ₁ and the washing solution A ₂ as the analysis solution A; finally use a certain amount of high-concentration organic alcohol to continue to analyze the resin, and collect the analysis solution B at the same time. Among them, the organic alcohol of the analytical resin is preferably ethanol, followed by methanol. The concentration of low-concentration organic alcohol is 15%-30% (V/V); the concentration of high-concentration organic alcohol is 50%-70% (V/V). The analytical solution A is an analytical solution containing punicalagin, and the analytical solution B is an analytical solution containing gallic acid, which can be determined through the steps of S208 product detection and content determination.

In S207, in the steps of extracting and crystallizing the analytical solution, the extraction times of the concentrated analytical solution A extracted with ethyl acetate and the concentrated analytical solution B extracted with chloroform are 2-3 times. Primary crystallization, dissolution, and recrystallization at a certain temperature refer to static crystallization at 4°C to 8°C for 12 hours to 18 hours, and low-concentration (15% to 30%) organic alcohol for primary crystallization corresponding to solution A dissolved, and the primary crystals corresponding to the analysis solution B were dissolved with high-concentration (50%-70%) organic alcohol, and then recrystallized at 4°C-8°C for 12-18 hours. Dry recrystallization by vacuum drying.

In the step of S208 product detection and content determination, HPLC is used to detect the composition and content of product a and product b. Product a is punicalagin with a content greater than 98%, and the recovery rate of the active substance is greater than 71%; product b is gallic acid with a content greater than 96%, and the recovery rate of the active substance is greater than 68%. The HPLC detection method can refer to the literature paper "Chinese Pharmacy, Volume 24, Issue 3, 2013, Simultaneous Determination of the Contents of Four Polyphenols in Pomegranate Peel by RP-HPLC, Authors Liu Zhenping, Chen Xianggui, Peng Haiyan, etc."

The calculation formula of the recovery rate is as follows:

Recovery rate=the quality of product*the mass percent of active substance in product/(the quality of raw material*the mass percent of active substance in raw material)*100%

Wherein, the active substance is punicalagin or gallic acid.

Embodiment one:

Yunnan Mengzi pomegranate peel raw material (the water content of the pomegranate peel raw material is less than 10%, the content of punicalagin is 5.2%, and the content of gallic acid is 1.1%) is pulverized by a grinder; 100 kg of the crushed pomegranate peel raw material is moved into 1 Add 500L of methanol with a concentration of 50% (V/V) to a cubic meter of ultrasonic extraction equipment, soak for 1 hour, heat to 60°C, and use 3KW ultrasonic power for ultrasonic reflux extraction for 2 hours to release the pomegranate peel extract; Concentrate the pomegranate peel extract under certain conditions to obtain a pomegranate peel concentrate with a relative density of 1.1g/cm ³ and a volume of 120L, while recovering methanol; then add 1200L of deionized water and 0.5 kg of chitin to the pomegranate peel concentrate Flocculant, 303 activated carbon for 5 kg of sugar, stirred for 5 minutes and then allowed to stand for 8 hours, the water decolorization solution was filtered with a plate and frame filter to remove chitin and sugar with 303 activated carbon, and then ultrafiltered with a vacuum fiber with a molecular weight cut-off of 30000Dal Membrane carries out ultrafiltration treatment, and obtains filtrate; Filtrate is adsorbed by polar macroporous adsorption resin HPD500 (resin for short); First wash resin with 500L deionized water, then use 300L concentration to be 15% (V/V) concentration Analyze methanol, collect the corresponding analysis solution A ₁ , then wash the resin with 200L deionized water, collect this part of the deionized water washing solution A ₂ at the same time, combine the analysis solution A ₁ and washing solution A ₂ as the analysis solution A ; finally use 400L concentration of methanol analysis resin of 50% (V/V) concentration, and collect analysis solution B simultaneously; Concentrate in vacuo again, stand for crystallization at 4°C for 12 hours, filter to obtain primary crystals, dissolve the primary crystals with 15% (V/V) concentration of methanol, and stand for recrystallization at 4°C for 12 hours, filter to obtain The recrystallized product was dried in vacuo to obtain 3.75 kg of product a; the analytical solution B was concentrated in vacuo, and the concentrated analytic solution B was extracted twice by adding chloroform, and the extracted lower layer liquid was concentrated in vacuo again, and left to crystallize at 4°C for 12 hours. Filtrate to obtain a primary crystal, which is dissolved in methanol at a concentration of 50% (V/V) and stand for recrystallization at 4° C. for 12 hours. Filter to obtain a recrystal, and obtain 0.78 kg of product b after vacuum drying; Product a was detected by HPLC as punicalagin with a content of 98.6%, and product b was gallic acid with a content of 96.7%. The recovery rate of the active substance punicalagin in product a was 71.1%, and the recovery rate of the active substance gallaginic acid in product b was 68.6%. %.

Embodiment two:

Yunnan Mengzi pomegranate peel raw material (the water content of the pomegranate peel raw material is less than 10%, the content of punicalagin is 5.2%, and the content of gallic acid is 1.1%) is pulverized by a grinder; 100 kg of the crushed pomegranate peel raw material is moved into 1 Add 600L of ethanol with a concentration of 80% (V/V) to the ultrasonic extraction equipment of cubic meters, soak for 2 hours, heat to 70°C, and use 10KW ultrasonic power for ultrasonic reflux extraction for 1.5 hours to release the pomegranate peel extract; Concentrate the pomegranate peel extract under certain conditions to obtain a pomegranate peel concentrate with a relative density of 1.2g/cm ³ and a volume of 115L, and recover ethanol at the same time; then add 1500L of deionized water and 0.3 kg of chitin to the pomegranate peel concentrate Flocculant, 3 kg of sugar with 303 activated carbon, stirred for 5 minutes and then allowed to stand for 10 hours, water precipitation and decolorization liquid was filtered with a plate and frame filter to remove chitin and sugar with 303 activated carbon, and then ultrafiltered with a vacuum fiber with a molecular weight cut-off of 40000Dal Membrane carries out ultrafiltration treatment, and obtains filtrate; Filtrate is adsorbed by polar macroporous adsorption resin HPD500 (resin for short); First wash resin with 500L deionized water, then use 300L concentration to be 25% (V/V) concentration Analyze with ethanol, collect the corresponding analysis solution A ₁ , then wash the resin with 200L deionized water, collect this part of the deionized water washing solution A ₂ at the same time, combine the analysis solution A ₁ and washing solution A ₂ as the analysis solution A ; finally use 400L concentration of ethanol analysis resin of 60% (V/V) concentration, collect analysis solution B simultaneously; Concentrate in vacuo, stand for crystallization at 6°C for 15 hours, filter to obtain primary crystals, dissolve the primary crystals with 25% (V/V) concentration of ethanol and stand for recrystallization at 6°C for 15 hours, filter to obtain heavy The crystalline substance, after vacuum drying, obtained 4.03 kg of product a; the analytical solution B was concentrated in vacuo, and the concentrated analytical solution B was extracted three times by adding chloroform, and the extracted lower layer liquid was concentrated in vacuum again, left to crystallize at 6°C for 15 hours, and filtered to obtain Primary crystallization, the primary crystallization was dissolved in ethanol with a concentration of 60% (V/V) and left to stand for recrystallization at 6°C for 15 hours, filtered to obtain the recrystallization, and vacuum-dried to obtain 0.86 kg of product b; detected by HPLC Product a is punicalagin with a content of 98.2%, and product b is gallic acid with a content of 96.1%. The recovery rate of the active substance punicalagin in product a is 76.1%, and the recovery rate of active substance gallic acid in product b is 75.1%.

Embodiment three:

Yunnan Mengzi pomegranate peel raw material (the water content of the pomegranate peel raw material is less than 10%, the content of punicalagin is 5.2%, and the content of gallic acid is 1.1%) is pulverized by a pulverizer; Add 1400L of ethanol with a concentration of 65% (V/V) to a cubic meter of ultrasonic extraction equipment, soak for 0.5 hours, heat to 80°C, and use 30KW ultrasonic power for ultrasonic reflux extraction for 1 hour to release the pomegranate peel extract; Concentrate the pomegranate peel extract under certain conditions to obtain a pomegranate peel concentrate with a relative density of 1.3g/cm ³ and a volume of 212L, and recover ethanol at the same time; then add 3000L of deionized water and 0.4 kg of polyacrylic acid to the pomegranate peel concentrate Flocculant, 303 activated carbon for 4 kg of sugar, stirred for 5 minutes and then allowed to stand for 12 hours, the water sedimentation and decolorization liquid was filtered with a plate and frame filter to remove polyacrylic acid and sugar with 303 activated carbon, and then ultrafiltered with a vacuum fiber with a molecular weight cut-off of 40000Dal The membrane is subjected to ultrafiltration treatment, and the filtrate is obtained; the filtrate is adsorbed by the polar macroporous adsorption resin LAS-7 (referred to as resin); the resin is first washed with 1000L deionized water, and then the resin is washed with 600L concentration of 30% (V/V) concentration of ethanol for analysis, collect the corresponding analysis solution A ₁ , then wash the resin with 400L deionized water, collect this part of the deionized water washing solution A ₂ at the same time, combine the analysis solution A ₁ and washing solution A ₂ as the analysis solution Solution A; finally use 800L concentration of ethanol analysis resin of 70% (V/V) concentration, collect analysis solution B simultaneously; Vacuum concentration analysis solution A, concentrated analysis solution A adds ethyl acetate and extracts twice, after extraction The lower liquid was concentrated again in vacuo, left to crystallize at 8°C for 18 hours, and filtered to obtain a primary crystal, which was dissolved in ethanol with a concentration of 30% (V/V) and then left to stand for recrystallization at 8°C for 18 hours. The recrystallized product was obtained by filtration, and 7.9 kg of product a was obtained after vacuum drying; the analytical solution B was concentrated in vacuo, and the concentrated analytical solution B was extracted twice by adding chloroform, and the extracted lower layer liquid was concentrated in vacuum again, and stood for crystallization at 8°C for 18 hour, filtered to obtain a crystallization, and the primary crystallization was dissolved in ethanol with a concentration of 70% (V/V) and left to stand for recrystallization at 8°C for 18 hours, and was filtered to obtain a recrystallization, and 1.64 kg of product b was obtained after vacuum drying Use HPLC to detect that product a is punicalagin with a content of 98.4%, product b is gallic acid with a content of 96.5%, the recovery rate of the active substance punicalagin in the product a is 74.7%, and the recovery rate of the active substance gallic acid in the product b was 71.9%.

The beneficial effect brought by the technical solution of the embodiment of the present invention is: the above method realizes the simultaneous separation and purification of punicalagin and gallic acid from pomegranate peel, and the content of separated and purified punicalagin is greater than 98%, and the content of gallic acid is greater than 96%, the recovery rate of punicalagin was greater than 71%, and the recovery rate of gallic acid was greater than 68%.

The above are only preferred embodiments of the present invention, and do not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any skilled person familiar with the profession , without departing from the scope of the technical solution of the present invention, when the technical content disclosed above can be used to make some changes or be modified into equivalent embodiments with equivalent changes, but as long as it does not depart from the technical solution of the present invention, the technical essence of the present invention Any simple modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

Claims (10)

1. A method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel, characterized in that, comprising steps: Raw material pretreatment: take the pomegranate peel raw material and grind it; Extraction: under a certain temperature condition, the crushed pomegranate peel is subjected to ultrasonic reflux extraction with a saturated alcohol with carbon atoms below 4 to obtain a pomegranate peel extract; Concentration: Concentrate the pomegranate peel extract to obtain the pomegranate peel concentrate, and recover the organic solvent at the same time; Water precipitation and decolorization: add appropriate amount of water, flocculant, and decolorization agent to the pomegranate peel concentrate to carry out water precipitation and decolorization, and filter to obtain the filtrate after water precipitation and decolorization for a period of time; Resin adsorption: the filtrate is adsorbed by the resin; Resin analysis: Wash the resin with deionized water, and then use low-concentration organic alcohol and high-concentration organic alcohol to analyze the resin successively, and collect the low-concentration organic alcohol analysis solution A and high-concentration organic alcohol analysis solution B; Analysis solution extraction and crystallization: Concentrate the analysis solution A, extract the concentrated analysis solution A with an appropriate amount of ethyl acetate, collect the lower layer extract and concentrate, crystallize, dissolve, recrystallize at a certain temperature, dry and recrystallize to obtain the isolated and purified product a At the same time, concentrate the analysis solution B, extract the concentrated analysis solution B with an appropriate amount of chloroform, collect the lower layer extract and concentrate, crystallize, dissolve, recrystallize at a certain temperature, dry and recrystallize to obtain the separation and purification product b; wherein, the product a is punicalagin with a content greater than 98%, and product b is gallic acid with a content greater than 96%. 2. The method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel as claimed in claim 1, characterized in that: in the extraction step, the saturated alcohol with carbon atoms below 4 is ethanol or methanol, and the concentration of ethanol or methanol is at 50 Between % and 80% (V/V), it needs to be soaked for 0.5 hours to 2 hours before ultrasonic reflux extraction, the extraction temperature is 60°C to 80°C, the ultrasonic reflux extraction time is 1 hour to 2 hours, and the ultrasonic power is 3KW ~30KW. 3. The method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel as claimed in claim 1, characterized in that: in the concentration step, the pomegranate peel extract is vacuum concentrated, and the pomegranate obtained by the vacuum concentration is The relative density of the skin concentrate is 1.1g/cm ³ -1.3g/cm ³ . 4. The method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peels as claimed in claim 1, characterized in that: in the water precipitation and decolorization step, the added water is deionized water, and the volume of added water is the concentration of pomegranate peels. 10 to 15 times the volume of the liquid, the weight of the flocculant added is 0.2% to 0.5% of the weight of the pomegranate peel raw material used, the weight of the decolorizer added is 2% to 5% of the weight of the pomegranate peel raw material used, water sinking, The decolorization time is 8-12 hours. 5. The method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel as claimed in claim 1 or 4, characterized in that: the filtration in the step of water precipitation and decolorization includes pressure filtration and ultrafiltration, and plate and frame filtration is used first The flocculant and decolorizing agent are filtered out by pressure filtration, and then the ultrafiltration membrane with a molecular weight cut-off greater than or equal to 30000Dal is used for ultrafiltration treatment to obtain the filtrate. 6. The method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel as claimed in claim 5, characterized in that: the ultrafiltration membrane is a vacuum fiber membrane. 7. The method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel as claimed in claim 1, characterized in that: in the resin adsorption step, the resin is a polar macroporous adsorption resin, and the polar macroporous Adsorption resin is LAS-7 polar resin or HPD500 polar resin. 8. The method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel as claimed in claim 1, characterized in that: in the resin analysis step, the organic alcohol is ethanol or methyl alcohol, and the low concentration of the organic alcohol is The concentration is 15%-30% (V/V), and the concentration of the high-concentration organic alcohol is 50%-70% (V/V). 9. The method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peel as claimed in claim 1, characterized in that: the analysis solution extraction and crystallization steps, ethyl acetate extraction and concentration analysis solution A and chloroform extraction concentration The extraction times of the analysis solution B were 2 to 3 times, respectively. 10. The method for simultaneously separating and purifying punicalagin and gallic acid from pomegranate peels as claimed in claim 1, characterized in that: in the steps of extracting and crystallizing the analytical solution, the control conditions for primary crystallization and recrystallization are at 4° C. to 8° C. Stand at ℃ for 12 hours to 18 hours for crystallization.