阅读说明：本技术 一种姜黄素提取纯化方法 (Curcumin extraction and purification method ) 是由 郑秋芳 方丽金 颜才健 于 2020-08-11 设计创作，主要内容包括：一种姜黄素提取纯化方法,包括以下步骤：S1将姜黄粉碎后加入第一有机溶剂,过滤后得到提取液；S2取得到的提取液通过第二提取树脂进行提取吸附；S3采用第三洗脱剂对所述第二提取树脂进行洗脱,收集洗脱液；S4取得到的洗脱液进行旋蒸、干燥得到姜黄素产品；所述第二提取柱由多孔树脂负载磺酸型金属螯合离子液体组成,其中,所述磺酸型金属螯合离子液体包含以下结构：<Image he="64" wi="276" file="100004_DEST_PATH_IMAGE001.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>(1)式(1)中,<Image he="16" wi="18" file="100004_DEST_PATH_IMAGE003.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>为金属螯合型阴离子。本发明利用多孔树脂负载磺酸型金属螯合离子液体制备得到提取树脂,可有效提高姜黄素的提取效率和纯度,且提取纯化步骤简单,利于实现姜黄素的工业化生产。(A curcumin extraction and purification method comprises the following steps: s1, crushing turmeric, adding a first organic solvent, and filtering to obtain an extracting solution; s2, extracting and adsorbing the obtained extracting solution through second extraction resin; s3, eluting the second extraction resin by using a third eluent, and collecting the eluent; s4 rotary evaporating the obtained eluent, and drying to obtain curcumin product; the second extraction column is composed of porous resin-loaded sulfonic acid type metal chelating ionic liquid, wherein the sulfonic acid type metal chelating ionic liquid comprises the following structure: (1) in the formula (1), the reaction mixture is, is metal chelating anion. The invention utilizes porous resin to load sulfonic acid type metal chelate ionThe extraction resin obtained by preparing the sub-liquid can effectively improve the extraction efficiency and purity of the curcumin, and the extraction and purification steps are simple, thereby being beneficial to realizing the industrial production of the curcumin.)

1. The curcumin extraction and purification method is characterized by comprising the following steps:

s1, crushing turmeric, adding a first organic solvent, and filtering to obtain an extracting solution;

s2, extracting and adsorbing the obtained extracting solution through second extraction resin;

s3, eluting the second extraction resin by using a third eluent, and collecting the eluent;

s4 rotary evaporating the obtained eluent, and drying to obtain curcumin product;

the second extraction column is composed of porous resin-loaded sulfonic acid type metal chelating ionic liquid, wherein the sulfonic acid type metal chelating ionic liquid comprises the following structure:

in the formula (1), the reaction mixture is,

2. The curcumin extraction and purification method as claimed in claim 2, wherein the curcumin is extracted and purified from the curcumin solution

3. The method for extracting and purifying curcumin as claimed in claim 2, wherein the preparation method of the sulfonic acid type metal chelating ionic liquid comprises: (1) mixing R-imidazole and 1, 3-propane sultone, adding acetone, stirring, reacting to obtain a solid, acidifying the solid, and washing and drying to obtain a sulfonated ionic liquid; dissolving chelating agent IDA or HFAC into acetonitrile, adding ammonia water, sealing, stirring at room temperature, and performing first rotary evaporation to obtain a solid; dissolving the obtained solid in ethanol, adding copper chloride, stirring at sealed room temperature, filtering, and performing secondary rotary evaporation to obtain a metal chelate product; (2) mixing the obtained sulfonated ionic liquid and a metal chelate product, reacting at sealed room temperature, filtering, performing third rotary evaporation, adding diethyl ether for dissolving, purifying, washing, performing fourth rotary evaporation, and drying to obtain the sulfonic acid type metal chelate ionic liquid.

4. A curcumin extraction and purification method as claimed in any one of claims 1 to 3, wherein the preparation method of the second extraction resin comprises: and dissolving the sulfonic acid type metal chelating ionic liquid in ethanol, stirring at room temperature, adding the porous resin, continuously stirring, distilling under reduced pressure to remove the ethanol, and drying to obtain the second extraction resin.

5. A curcumin extraction and purification method as claimed in claim 4, wherein said porous resin is DM301 or DA 201.

6. The method for extracting and purifying curcumin as claimed in claim 5, wherein the mass-to-volume ratio of the second extraction column to the extraction solution in the step S2 is 5-10 g/100 ml.

7. The method for extracting and purifying curcumin as claimed in claim 1, wherein said first organic solvent is one of ethanol and acetone.

8. The method for extracting and purifying curcumin as claimed in claim 1, wherein said third eluent is one of ethanol and acetone.

9. The method for extracting and purifying curcumin as claimed in claim 8, wherein the flow rate of the third eluent in the step S3 is 1-3 ml/min.

10. The method for extracting and purifying curcumin as claimed in claim 8, wherein the pH of ethanol or acetone used as the third eluent is 7.5 to 8.0.

Technical Field

The invention belongs to the technical field of plant extraction and separation, and particularly relates to a curcumin extraction and purification method.

Background

Turmeric (Curcuma longa L.) is a perennial herb of Zingiberaceae, also known as Curcuma longa L, and is a traditional medicinal material with homology of medicine and food. The medicinal material value of turmeric means that dried rhizome thereof is widely cultivated in tropical and subtropical regions, particularly in southeast Asia and northern Australia, and is mainly distributed in China, Africa, USA, Japan, etc. The areas for planting the turmeric in China are more, and the method mainly focuses on Sichuan, Fujian, Hunan, Guangdong, Yunnan, Tibet, Guizhou, Taiwan and the like.

The turmeric has pungent, bitter and mild taste, enters heart, liver and spleen, has the effects of breaking blood and promoting qi circulation and stimulating the menstrual flow to stop bleeding, has a long medicinal history, is commonly used for treating chest pain, amenorrhea, abdominal mass, rheumatic pain, traumatic injury and other symptoms in ancient Chinese pharmacology, has the effects of antisepsis and sterilization, and can also be used for treating incised wound, burn and bruise. In addition, turmeric has a good health-care effect, and is also used for assisting in treating diseases such as stomachache, dyspepsia and the like. In the field of modern Chinese medicine, the preparation method is mainly used for producing Chinese medicine preparations.

The Curcuma rhizome mainly contains curcumin and Curcuma rhizome volatile oil, and also contains resins, saccharides, sterols, polypeptides, fatty acids, monoenoic acid, dienoic acid, alkaloids, trace elements, etc. In recent years, research on turmeric at home and abroad mainly focuses on the extraction and purification of active ingredients curcumin and curcuma oil and research on corresponding effects, and the aspects of separating and exploring new drugs from turmeric active ingredients, identifying structures, chemically synthesizing, modifying and the like are the key points of research of broad scholars.

Curcumin is a natural pigment, and is widely applied to foods such as cakes, candies, beverages, sausage products, cans and the like due to high colorability. Most of the existing artificial pigments can cause certain harm to human bodies, while curcumin serving as a natural pigment is almost non-toxic and harmless, and gradually replaces the artificial pigments. Curcumin is a slightly acidic diphenyl heptahydrocarbon substance, is an extremely rare diketone colored substance, and is a compound with a special structure of polyphenols. In generalReference to curcumin generally refers to the collective name curcumin monomer, demethoxycurcumin monomer and bisdemethoxycurcumin monomer. Curcumin is an orange crystalline powder, slightly bitter in taste, insoluble in water, soluble in ethanol, propylene glycol, glacial acetic acid and alkali solution. Therefore, by utilizing the characteristics of curcumin, the existing extraction method for turquoise generally comprises the following steps: ethanol reflux method, percolation method, sodium salicylate method, enzyme method, ultrasonic method, microwave extraction method and supercritical CO₂Methods, and the like. Further purification is required to obtain a purer curcumin product, and methods for purifying curcumin generally include: organic solvent extraction, column chromatography, etc. However, the traditional organic solvent method for extracting curcumin causes the problem of solvent residue, and the extraction method combined with an enzyme method can obviously improve the extraction rate, but the added enzyme is difficult to effectively separate from the product, and the extraction method is difficult to separate the pigment and the grease contained in the turmeric.

The ionic liquid is a salt which is in a liquid state at or near room temperature and completely consists of anions and cations, and is also called low-temperature molten salt. Compared with the traditional organic solvent, the ionic liquid has the advantages of low vapor pressure, wide viscosity range, good conductivity, strong dissolving capacity, high thermal stability and the like. Meanwhile, the ionic liquid has good designability, namely the polarity, the solubility, the hydrophobicity, the hydrophilicity and other physical and chemical properties of the ionic liquid can be adjusted through anion and cation combination or group modification. Since the ionic liquid has the above-mentioned advantages, it has attracted the attention of many researchers. For example, the document with the application number of 201711237710.6 discloses a method for extracting and preparing bamboo leaf flavone by using ionic liquid, which comprises the following process steps: adding crushed and sieved bamboo leaf powder into an ionic liquid aqueous solution A, performing ultrasonic-assisted extraction to obtain an extracting solution, and filtering the extracting solution to obtain a filtrate A and a solid material A; adding the solid material A into an ionic liquid aqueous solution B, performing ultrasonic-assisted extraction to obtain an extracting solution, and filtering the extracting solution to obtain a filtrate B; and adding an organic solvent into the filtrate B for extraction, standing for layering to obtain an upper organic phase extracting solution and a lower raffinate, and concentrating the upper organic phase extracting solution under reduced pressure to obtain the bamboo leaf total flavonoids. The method is a new process for extracting and preparing bamboo leaf flavone, the obtained bamboo leaf flavone has high extraction rate, high purity and quality, the ionic liquid can be recycled, the operation is convenient, and the method has good popularization and application prospects.

However, the ionic liquid is not suitable for curcumin extraction, the inventor researches and obtains an extraction method suitable for curcumin according to the property of the curcumin, researches the optimal process parameters of the curcumin extraction method by taking the curcumin yield as an investigation index, and determines the optimal purification process conditions.

Disclosure of Invention

Aiming at the problems, the invention aims to provide a curcumin extraction and purification method, which is characterized in that the extraction resin is prepared by using porous resin loaded sulfonic acid type metal chelating ionic liquid, the extraction efficiency and purity of curcumin can be effectively improved, the extraction and purification steps are simple, and the industrial production of curcumin is favorably realized.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a curcumin extraction and purification method comprises the following steps: s1, crushing turmeric, adding a first organic solvent, and filtering to obtain an extracting solution; s2, extracting and adsorbing the obtained extracting solution through second extraction resin; s3, eluting the second extraction resin by using a third eluent, and collecting the eluent; s4 rotary evaporating the obtained eluent, and drying to obtain curcumin product;

the second extraction column is composed of porous resin-loaded sulfonic acid type metal chelating ionic liquid, wherein the sulfonic acid type metal chelating ionic liquid comprises the following structure:

（1）

in the formula (1), the reaction mixture is,

is metal chelating anion.

In the design of the scheme, the sulfonic acid type metal chelating ionic liquid reinforced porous resin has the advantages that the ionic liquid has the advantages of strong designability, high capacity, recycling, environmental friendliness and the like, the ionic liquid is designed aiming at the specific structure of curcumin on the basis, and the curcumin has a hydrophilic group and a hydrophobic group (the whole curcumin is insoluble in water), so that the sulfonic acid type metal chelating ionic liquid provided by the invention has a polar head and a nonpolar tail and can be completely adapted to the structure of the curcumin, the specificity of curcumin extraction is stronger, the sulfonic acid group in the ionic liquid has stronger selectivity on aromatic hydrocarbon, and the introduction of the sulfonic acid group can improve the selectivity and the extraction capacity on the curcumin. Because the stability of the metal chelating anion is high enough, other byproducts can not be generated during the preparation, the metal chelate is easier to adsorb and fix on the resin, and meanwhile, the chelating metal anion can reduce the lattice energy of the ionic liquid and can ensure that the ionic liquid is in a stable liquid state at room temperature, the preparation of the resin can be completed by adopting a wet impregnation-evaporation method. The preparation of the extraction resin has the advantages that the curcumin can be extracted in one step, and the extraction efficiency is high.

As a further preferred aspect of the present invention, the above-mentionedThe ion is selected from

、

One kind of (1).

In this scheme design, select for use transition metal copper, its advantage lies in that copper ion is comparatively ripe at the technique of preparing chelate ionic liquid to copper ion itself has the colour, can be used to judge the adsorption efficiency when the reaction process in the preparation process also can be used to judge preparation resin. Meanwhile, the tridentate ligands of the two copper ions have higher acid-base and thermal stability, and are beneficial to improving the extraction of curcumin, so that the tridentate ligands are the preferred choice in the invention.

As a further preferred aspect of the present invention, the method for preparing the sulfonic acid type metal chelate ionic liquid comprises: (1) mixing R-imidazole and 1, 3-propane sultone, adding acetone, stirring at 30-50 ℃, reacting to obtain a solid, acidifying the solid with concentrated acid, and washing and drying to obtain a sulfonated ionic liquid; dissolving chelating agent IDA or HFAC into acetonitrile, adding ammonia water, stirring at sealed room temperature, and performing first rotary evaporation to obtain a solid; dissolving the obtained solid in ethanol, adding copper chloride, stirring at sealed room temperature, filtering, and performing secondary rotary evaporation to obtain a metal chelate product; (2) mixing the obtained sulfonated ionic liquid and a metal chelate product, reacting at sealed room temperature, filtering, performing third rotary evaporation, adding diethyl ether for dissolving, purifying, washing, performing fourth rotary evaporation, and drying to obtain the sulfonic acid type metal chelate ionic liquid.

In the present invention, the R-based imidazole is preferably a short chain methyl imidazole, which helps to reduce van der Waals forces to reduce the viscosity of the ionic liquid. The three-step method for synthesizing the sulfonic acid type metal chelate ionic liquid provided by the invention has the strategy that organic cation modification is respectively carried out to prepare the metal ion chelate, and then the ionic liquid is synthesized. The method has few byproducts, simple preparation process and easy separation and recovery of redundant reagents.

As a further preferred aspect of the present invention, the method for preparing the second extraction resin comprises: and dissolving the sulfonic acid type metal chelating ionic liquid in ethanol, stirring at room temperature, adding the porous resin, continuously stirring, distilling under reduced pressure to remove the ethanol, and drying to obtain the second extraction resin.

As a further preferred aspect of the present invention, the porous resin is DM301 or DA 201.

In the invention, DM301 is a nonpolar resin, DA201 is a strong polar resin, and the resins have good adsorption to curcumin, and based on the basis, the inventor uses ionic liquid to strengthen the resins and the DA201, and experiments prove that the adsorption efficiency and the adsorption of the strengthened resins are improved.

In a further preferred embodiment of the present invention, the mass-to-volume ratio of the extract liquid to the second extraction column in the step S2 is 5 to 10g/100 ml.

In a further preferred embodiment of the present invention, the first organic solvent is one of ethanol and acetone.

In a further preferred embodiment of the present invention, the third eluent is one of ethanol and acetone.

In a further preferred embodiment of the present invention, the flow rate of the third eluent in the step S3 is 1-3 ml/min.

In a further preferred embodiment of the present invention, the pH of the ethanol or acetone used as the third eluent is 7.5 to 8.0.

In the invention, the pH value of the eluent is different from the commonly selected acidity or neutrality, and the alkalescent eluent is selected because the ionic liquid prepared by the invention has poor elution effect in acidic and neutral environments and good elution effect in alkaline conditions, but the alkalescent eluent is selected in consideration of unstable curcumin caused by over-strong alkalinity.

The invention has the following beneficial effects:

the extraction resin adopted by the invention can complete the extraction of curcumin in one step, so that the extraction process of curcumin is greatly optimized, the extraction efficiency is high, the extraction effect is good, and the purity of the obtained curcumin is high.

The novel extraction resin obtained by combining the sulfonic acid type metal chelating ionic liquid and the resin has the advantages of simple preparation process, easiness in implementation, higher acid-base and thermal stability, color, easiness in observation and convenience in treatment operation.

Drawings

FIG. 1 is a comparison of loading and unloading of the first extraction resin of the present invention.

(a) Is a pre-loaded resin; (b) the resin is loaded with ionic liquid.

Detailed Description

Material preparation

Reagent: hexafluoroacetylacetone (HFAC, more than or equal to 99 percent), copper chloride dihydrate (more than or equal to 99 percent), ammonia water (25-28 percent), acetonitrile (more than or equal to 99 percent), ethanol (more than or equal to 99 percent), N-methylimidazole (99 percent), formic acid (analytically pure), 1, 3-propane sultone (analytically pure), acetone (analytically pure), concentrated sulfuric acid (more than or equal to 99 percent), ethyl acetate, deionized water and the like.

Second, Experimental methods

1. Preparation of Ionic liquids

(1) Adding 10mmol hexafluoroacetylacetone (liquid) into a 250ml single-neck round-bottom flask, adding 50ml acetonitrile as a solvent, finally adding equimolar ammonia water, sealing, and reacting for 24 hours under magnetic stirring at room temperature. After the reaction is finished, 3.33mmol of copper chloride dihydrate is added, 20-30ml of ethanol is added for dissolution, and the mixture is stirred and reacted for 10-12h at room temperature. After the reaction is finished, the by-product ammonium chloride is filtered, and acetonitrile and ethanol are distilled off by a rotary evaporator to obtain a metal chelate product. The reaction process is as follows:

the preparation process is similar to hexafluoroacetylacetone by using IDA as a chelating agent, and the reaction process of the obtained metal chelating product is as follows:

(2) methyl imidazole and 1, 3-propane sultone are weighed according to the molar ratio of 1:1, are added into a 250ml round-bottom flask, acetone is used as a solvent, and are electromagnetically stirred for 17 hours at the temperature of 40 ℃, so that the methyl imidazole and the 1, 3-propane sultone are subjected to condensation reaction. Stopping stirring, carrying out suction filtration to obtain a white solid, washing the sub-white solid with acetone and ethanol again, filtering to obtain white powder, drying the white powder in a vacuum drying oven at 80 ℃ for 4 hours, taking out and weighing the white powder, then acidifying the white powder with equal mass of concentrated sulfuric acid at 80 ℃ for 6 hours to obtain a transparent solution, washing the transparent solution with a proper amount of ethyl acetate for three times, and then drying the solution for a certain time to obtain a sulfonated ionic liquid product.

(3) Adding the obtained metal chelate product and the sulfonated ionic liquid product into a 250ml round-bottom flask according to the amount of the substances, reacting for 10-12h, filtering out a by-product ammonium chloride after the reaction is finished, and evaporating residual acetone, ethanol and ethyl acetate by a rotary evaporator to obtain green liquid.

(4) Dissolving the obtained green liquid in ether, filtering out residual ammonium chloride, transferring filtrate to a separating funnel, washing for 4-6 times by using ultrapure water, detecting that no halogen ion remains, then evaporating the ether by using a rotary evaporator, and drying the obtained product in vacuum for 24 hours to obtain purified ionic liquid, namely the sulfonic acid type metal chelate ionic liquid.

The inventor mainly prepares two ionic liquids, namely cations are as follows:

；

the anion is one of the following two types:

；。

2. preparation of the extraction resin

Dissolving the prepared ionic liquid in ethanol at a ratio of 1g/10ml, stirring at room temperature for 5-15 min, respectively adding the two resins, stirring for 60min, distilling at 35 ℃ under reduced pressure to remove ethanol, and drying at 60 ℃ in vacuum for 12h to obtain four porous resin-loaded ionic liquids, wherein the four porous resin-loaded ionic liquids are shown in the following table:

thirdly, extracting curcumin