CN101007797A - Method for extracting dihydromyricetin from Japanese raisin tree seed - Google Patents

Abstract

The invention discloses a method for extracting dihydromyricetin from Hovenia dulcis. The extraction method of the present invention firstly obtains the extract that is rich in dihydromyricetin by pretreating medicinal materials, then further purifies by using resin, and finally recrystallizes to obtain high-purity dihydromyricetin (purity > 99%), which overcomes the The cumbersome operation process of the previous extraction method has the advantages of simple operation, low toxicity, low cost, strong controllability, and large-scale production.

Description

A method for extracting dihydromyricetin from Hovenia dulcis

technical field

The invention relates to dihydromyricetin, in particular to a method for extracting dihydromyricetin from Hovenia dulcis fruit.

Background technique

Hovenia dulcis Thunb., Hovenia acerba Lindl. and Hovenia trichocarpa Chun et al. Tsiang) has a medicinal history of thousands of years. There are 3 species and 2 varieties in the world, mainly distributed in China, Korea, Japan and India. Our country is very rich in resources, which are distributed in all provinces except Northeast China, Inner Mongolia, Xinjiang, Ningxia, Qinghai and Taiwan. It was first recorded in "Tang Materia Medica", and it is used as medicine with fruits, seeds, wood juice, and wood bark. It is now recorded in "Drug Standards of the Ministry of Health of the People's Republic of China Chinese Medicinal Materials". Flavonoids are the active ingredients of Hovenia dulcis. According to the pharmacological experiment reports of Japanese scholars, it has been confirmed that dihydromyricetin extracted from the fruit of Hovenia dulcis produced in Japan has shown excellent hepatoprotective activity, and its activity is higher than the present Yiganling (Hase K, OhsugiM, Xiong Q, et al. Hepatoprotective effect of Hovenia dulcis THUNB. on experimental liver injuries induced by carbon tetrachioride or D-galactosamine/lipopolysaccharide[J].Biol.Pharm.Bull ., 1997, 20(4): 381-385.). In addition, modern science has also confirmed that dihydromyricetin has the functions of liver protection, anti-inflammation, analgesia, lowering blood fat, increasing SOD activity, strong antioxidant effect, good antibacterial and antiviral effects, and is expected to be developed It is a new type of health care product and natural food antioxidant as well as a national first and second class new drug. Its chemical name is 3,5,7,3',4',5'-hexahydroxy 2,3 dihydroflavone, its English name is Dihydromyricetin (abbreviated as DMY) or (+)-ampelopsin, and its molecular structure formula is as (I) shown.

However, the main plant source of dihydromyricetin today is the vine tea of the genus Vitis genus, and its extraction process is cumbersome and highly toxic.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of existing dihydromyricetin extraction methods, and provide a method for extracting dihydromyricetin from Hovenia dulcis fruit with simple operation and low toxicity.

The present invention extracts the method for dihydromyricetin from Hovenia dulcis medicinal material, and its steps are as follows:

1. Pulverize the clean Hovenia dulcis medicinal material, extract with a low-polarity organic solvent, and filter to obtain a filter residue;

2. The filter residue obtained above is reflux extracted with an aqueous alcohol solution;

3. Resin adsorption separation: Concentrate the extract obtained in step (2), make it pass through a macroporous resin or polyamide column, first elute with water to remove some impurities, and then use 5% to 10% (V/V) alcohol aqueous solution Elute to remove some impurities, and finally use 20% to 30% (V/V) alcohol aqueous solution for elution; when 6 to 7 BV are eluted, stop elution and combine the eluents of this section;

4. Concentration and recrystallization: Concentrate the eluate obtained in step 2, then heat-dissolve and recrystallize it with an aqueous alcohol solution, let it stand, filter the crystals, and dry to obtain dihydromyricetin with a purity of more than 99%.

Hovenia dulcis medicinal materials in the above step 1 include Hovenia dulcis Thunb. plants Hovenia dulcis Thunb., Hovenia acerba Lindl. and Hovenia trichocarpa Chun et Tsiang. Ripe fruit or dry seeds.

The low-polarity organic solvent in the above step 1 is fatty ether or 6# gasoline; the fatty ether is ether, sherwood oil or n-hexane.

When the alcoholic aqueous solution described in above-mentioned steps 2 is extracted, its alcoholic aqueous solution is the aqueous solution of methyl alcohol, ethanol, propanol, butanol or pentanol, and the volume ratio concentration of organic solvent in its mixed solvent is 50%～100% (V/ V).

The amount of the extraction solvent in the above step 2 is 6-10 times the amount of the medicinal material, the extraction times are 2-4 times, and the extraction method is heat reflux extraction, dipping extraction, ultrasonic extraction, or percolation extraction.

The macroporous resin column used in the above step 3 is a macroporous resin column composed of styrene as a raw material and divinylbenzene, methacrylonitrile or methyl acrylate as a crosslinking agent. Macroporous resin refers to D-101 type, HPD-500 type, HP-20 type, XAD-4 type, AB-8 type, SP-825 type, NKA type, SIP-1100 type or XAD-2 type macroporous resin.

The alcohol aqueous solution of the recrystallization solvent in the above step 4 is the aqueous solution of methanol, ethanol, propanol, butanol or pentanol, and the volume ratio concentration of the organic solvent in the mixed solvent is 0%～50% (V/V).

The drying in the above step 4 is normal pressure drying, vacuum drying under reduced pressure, spray drying or freeze drying.

Compared with the prior art, the present invention has the following beneficial effects: the extraction method of the present invention first obtains an extract rich in dihydromyricetin by pretreating the medicinal materials, then further purifies by using resin, and finally obtains high-purity dihydromyricetin by recrystallization. The dihydromyricetin (purity > 99%) overcomes the cumbersome operation process of the previous extraction methods, and has the advantages of simple operation, low toxicity, low cost, strong controllability, and large-scale production.

Description of drawings

Fig. 1 is dihydromyricetin (DMY) extraction separation roadmap;

Figure 2 is the hydrogen spectrum of DMY.

Detailed ways

Example 1

1. Get the dry seeds (1kg) of Hovenia dulcis, remove impurities, pulverize them, and pass through a 80-100 mesh sieve;

2. Use 8 times the amount of petroleum ether with a boiling range of 60-90 to reflux extraction for 2 hours, and then use 6 times the amount of petroleum ether with a boiling range of 60-90 to reflux extract twice, each time for 1.5 hours, filter to obtain a filter residue , combine the extracts, and recover the solvent.

3. The filter residue obtained above was reflux extracted with 8 times the amount of 70% ethanol for 2 hours, and then refluxed with 70% ethanol for 2 times, each time for 1.5 hours;

4. Concentrate the extract under reduced pressure, put it on the AB-8 macroporous resin column, load the sample slowly, first elute with water until the effluent is nearly colorless, then use 10% ethanol to elute for 5 times the column retention volume, and finally use 30% Ethanol elution, when the elution reaches 6 times the column retention volume, stop the collection, and recover the solvent from the 30% ethanol elution;

5. The concentrated solution obtained above was hot-dissolved with 20% ethanol, left standing at 0-5°C for 12 hours, and white needle-like crystals were precipitated, the crystals were filtered with suction, and spray-dried to obtain 4.0 g of dihydromyricetin, which The hydrogen spectrogram is shown in Figure 2.

Claims (10)

1. a method for extracting dihydromyricetin from Hovenia dulcis, the steps are as follows: (1) Pulverize Hovenia dulcis medicinal material, pass through 80-100 mesh sieves, then extract with low-polarity organic solvent, filter to obtain filter residue; (2) Carry out reflux extraction with the above-mentioned obtained filter residue with alcoholic aqueous solution; (3) Resin adsorption separation: Concentrate the extract obtained in step (2), make it pass through a macroporous resin column or polyamide resin, first wash with water to remove some impurities, and then use an aqueous alcohol solution with a volume ratio of 5 to 10:100 Part of the impurities are removed by elution, and finally eluted with an aqueous alcohol solution with a volume ratio of 20 to 30:100; when 6 to 7 BV are eluted, stop elution and combine the eluents of this section; (4) Concentration and recrystallization: Concentrate the eluent obtained in step (3), then heat-dissolve and recrystallize it with an aqueous alcohol solution, let stand, filter the crystals, and dry to obtain dihydromyricetin. 2. according to the described method of claim 1, it is characterized in that, the Hovenia dulcis medicinal material described in step (1) is the mature fruit or dried seed. 3. by the described method of claim 1, it is characterized in that, the described low polarity organic solvent of step (1) is aliphatic ether, normal hexane or 6# gasoline. 4. by the described method of claim 3, it is characterized in that, described aliphatic ether is ether, sherwood oil or normal hexane. 5. according to the described method of claim 1, it is characterized in that, the aqueous alcohol solution described in step (2) is the aqueous solution of methyl alcohol, ethanol, propanol, butanol or pentanol, and the volume ratio of alcohol and water is 50～100 : 100. 6. The method according to claim 1, characterized in that the amount of the alcoholic aqueous solution in step (2) is 6 to 10 times the amount of medicinal material, the number of extractions is 2 to 4 times, and the extraction method is heat reflux extraction, immersion extraction , ultrasonic extraction or percolation extraction. 7. by the described method of claim 1, it is characterized in that, the resin column described in step (3) is macroporous resin or polyamide; Wherein macroporous resin is to be raw material with styrene, divinylbenzene, methacrylate Dilute nitrile or methyl acrylate is a macroporous resin column composed of crosslinking agent. 8. Press the described method of claim 7, it is characterized in that, described macroporous resin refers to D-101 type, HPD-500 type, HP-20 type, XAD-4 type, AB-8 type, SP- 825 type, NKA type, SIP-1100 type or XAD-2 type macroporous resin. 9. by the described method of claim 1, it is characterized in that, the described alcohol aqueous solution of step (4) is the aqueous solution of its methyl alcohol, ethanol, propanol, butanol or pentanol, and the volume ratio of alcohol and water is 0～ 50:100. 10. The method according to claim 1, characterized in that the drying described in step (4) is normal pressure drying, vacuum drying under reduced pressure, spray drying or freeze drying.

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