CN102276515A - Method for extracting deoxynojirimycin - Google Patents

Abstract

The invention discloses a method for extracting a deoxynojirimycin monomer. The method comprises the following steps of: soaking a mulberry raw material in acidic aqueous solution, and extracting for 1 to 3 times; adsorbing extracting solution on a cation exchange resin, washing, and eluting by using ammonia water; performing reverse osmosis pre-concentration on eluent, recovering ammonia, dissolving an intermediate in a hydrophilic solvent, performing catalytic conversion, allowing the solution to pass through a gel chromatographic column, and eluting the hydrophilic solvent; recovering the solvent, dissolving in a mixed solvent, allowing the mixed solvent to pass through the chromatographic column, and eluting the mixed solvent; and recovering the mixed solution to obtain pure deoxynojirimycin products. The method is low in energy consumption and environment-friendly, and the pure deoxynojirimycin products with various purity grades of 10 percent, 50 percent, 99 percent and the like.

Description

A kind of deoxynojirimycin extraction method

technical field

The invention relates to biological extraction technology, in particular to a method for extracting deoxynojirimycin monomer.

Background technique

1-deoxynojirimycin (1-deoxynojirimycin, DNJ) is a polar N-containing compound, its chemical name is 3, 4, 5-trihydroxy-2-hydroxymethyltetrahydropyridine, and its molecular formula is C ₆ H ₁₃ NO ₄ , the relative molecular mass is 163. DNJ has a strong inhibitory effect on α-glucosidase, and is an effective ingredient for lowering blood sugar and treating diabetes ^[1-4] . In addition, it also has pharmacological effects such as anti-virus ^[5] and anti-tumor metastasis ^[6] . In recent years, scholars at home and abroad have conducted a lot of research and exploration on the source of DNJ, its synthesis mechanism in vivo and chemical synthesis methods, hoping to find a stable, efficient and economical way to obtain DNJ ^[7] .

Li Yuliang ^[8] reported a method for extracting deoxynojirimycin from mulberry leaves, which mainly includes extraction, extracting through cation exchange resin, n-butanol extraction and other steps to obtain pure deoxynojirimycin. The process requires extraction with n-butanol; n-butanol is more expensive and the production cost is higher.

Liu Weijun ^[9] reported a method for extracting deoxynojirimycin from mulberry leaves, including extracting mulberry leaves with 70% ethanol, concentrating the extract, passing it through a macroporous adsorption resin, and passing the effluent of the macroporous adsorption resin, Concentrate, pass through a cation exchange resin, wash with distilled water, elute with 0.5 mol/L ammonia water, collect the eluate, concentrate, purify the concentrated solution through silica gel, discard the components with impurities, and combine the 1-deoxynojirimycin-containing The purer components were concentrated and dried in vacuum to obtain 1-deoxynojirimycin (DNJ). This process requires ethanol extraction, and needs to pass through a macroporous resin before adding cation exchange quality, and concentrate it 4 times; the process consumes a lot of energy, and the cost of using ethanol is also high.

Zhou Huiyan ^[10] et al. reported the method of extracting and purifying deoxynojirimycin by reverse column chromatography, and the content of deoxynojirimycin reached 10.7%; this technique failed to obtain a pure product.

Liu Shuxing ^[11] et al. used DXA-6 resin to pack the column, pH 10, stock solution concentration 0.352 mg/mL, and flow rate 2.0 BV/h for adsorption, and 80% ethanol solution for elution at a flow rate of 2.5 BV/h to extract deoxynojirimycin . The extraction process requires the use of ethanol, and the purity of the final product is not known.

Chinese patent technology (03101988.9) reported a preparation containing mulberry leaf total alkali extract and its preparation method: mulberry leaves were extracted with water or a hydrophilic solvent, flocculated, the supernatant was ion-exchanged, the hydrophilic solvent was refluxed, concentrated to Dried to obtain extract. The purity of the product reaches more than 50%, and the preparation has obvious effects of lowering blood sugar and improving glucose tolerance. This method requires flocculation; the substances adsorbed by the resin need to be eluted by reflux with a hydrophilic solvent, which is somewhat inconvenient in actual operation.

Chinese patent technology (02113004.3) reports the extract of mulberry branch and its extraction method and new application: the extract of mulberry branch is prepared by using 0-95% ethanol aqueous solution or chloroform, acetone, ethyl acetate, methanol and other solvents or Their combination is extracted once or more under the temperature condition of 10-100°C, the extracts are combined, and the solvent is recovered; or the following methods are used for further purification: the pH of the extract is adjusted to 7.5-9.5, and the supernatant after centrifugation is adjusted to 7.5-9.5. The pH is 4-6, the precipitate is washed to neutral, and dried; the extract is obtained by degreasing petroleum ether or gasoline; Or obtained by sequential extraction; the extract is absorbed by macroporous adsorption resin, and then desorbed with 10-95% ethanol aqueous solution; after the extract is absorbed by diatomaceous earth, alumina, etc. After eluting with solvents such as methanol and ethanol, it is obtained by concentrating and drying; the extract is separated by column chromatography such as polyamide, silica gel or ion exchange resin. The above purification methods can be used alone or in combination of several methods. The obtained Morus mulberry extract contains a large amount of flavonoids, including rutin, quercetin, morin and the like. The patented technology does not specify the purity of the DNJ contained in the extract, and the purification process involves complex operating procedures such as petroleum ether degreasing and macroporous resin adsorption.

Chinese patent technology (200710060127.2) reported a method for continuous extraction of active ingredients of alkaloids, flavonoids and polysaccharides from mulberry leaves: the solvent is 20% to 90% ethanol or 10% to 90% acetone for reflux extraction to obtain filtrate and filter residue After the filtrate is concentrated and dissolved in water, flavonoids with a content of 30% to 50% are separated by macroporous resin; the solution after passing through the macroporous resin is separated by ion exchange resin to obtain flavonoids with a content of 40% to 60%. Alkali compound; mulberry leaf filter residue, decocting with water, decolorizing, 10%-60% alcohol precipitation, to obtain acidic polysaccharide compound with a content of 55%-85%. This technology requires a large amount of ethanol or acetone for extraction, the cost of the process technology is high, the energy consumption is high, and the pure product of DNJ cannot be obtained.

Chinese patent technology (200510030333.X) reported a method for extracting active ingredients from mulberry leaves: the resin adsorbed with mulberry leaf extract was placed in an extraction kettle, and _CO was continuously introduced for extraction and elution, and the effluent from the extraction kettle was collected. CO ₂ , depressurize to normal pressure, CO ₂ is vented or pressurized and then reused to obtain the residue after depressurization, which is the active ingredient of mulberry leaves. The CO ₂ in the extraction kettle is in a supercritical state. The method of the present invention is not easily oxidized in the purification process, and is convenient for large-scale extraction and purification of mulberry leaf deoxynojirimycin alkaloids and mulberry leaf flavonoids, and has high selectivity. Among the products, deoxynojirimycin alkaloids and mulberry leaf The total content of lutein can reach 75-90%. The technology adopts supercritical extraction technology, and the final product does not obtain pure deoxynojirimycin.

Chinese patent technology (200710067498.3) reported a method of extracting 1-deoxynojirimycin from mulberry leaves: adding inorganic acid to the extract of mulberry leaves for acidification, cooling to remove impurities, and then obtaining through column chromatography. The content of mulberry leaf extract can be made not less than 10%, but no pure product can be obtained.

Chinese patent technology (200810122998.7) reported a method for separating 1-deoxynojirimycin monomer from the total alkaloids of mulberry leaves: the total alkaloids of mulberry leaves were dissolved in water, adsorbed by ion exchange resin, after the adsorption was completed, distributed elution and The pure part of deoxynojirimycin was collected, concentrated and dried under reduced pressure, and recrystallized several times to obtain the pure product. This method requires that the "total alkaloids" of the raw material contain more than 40% of deoxynojirimycin, and the step-by-step eluents are alcohol solutions of different concentrations, and the recrystallization is a mixed solution of methanol and acetone; a large amount of detection work is required during the step-by-step elution And the collection of pure product parts, the operation is more troublesome, and the mixed solvent of recrystallization is difficult to handle.

Chinese patent technology (200810236144.1) reported a composite extraction process for the co-production of mulberry leaf flavonoids, polysaccharides and alkaloids, but no pure deoxynojirimycin was obtained.

Chinese patent technology (200910192542.2) reported a method of continuous extraction and separation of 1-deoxynojirimycin (DNJ) and flavonoids from mulberry leaves: mixing mulberry leaves with ethanol, extracting, centrifuging, concentrating, adding flocculant to flocculate and precipitate After removing the precipitate, the filtrate is added to a plurality of connected cation exchange resin columns, and flows through the macroporous adsorption resin column connected in series with the resin column; after the filtrate adds, it is washed with pure water until the macroporous resin column effluent has no Disconnect it when it is colored, and then use ammonia water or ammonia-containing ethanol solution to elute 1-deoxynojirimycin (DNJ) from the cationic resin column; the eluent is then loaded on the cationic resin column, and the eluent is collected after repeated operations. Concentrate and filter with an 80D nanofiltration membrane and spray dry to obtain 1-deoxynojirimycin (DNJ) in the form of a brownish-yellow powder. Wash the macroporous resin column with 3%-10% ethanol to remove colloidal impurities, then elute flavonoids with 50%-70% ethanol, collect the brown-red eluate, concentrate under reduced pressure to recover ethanol, and then spray dry to obtain yellow-brown Powdered total flavonoids of mulberry leaves. The raw materials of this technology need to be extracted repeatedly with ethanol, and the production cost is high, and the energy consumption is also high.

Chinese patent technology (200710099911.4) reported a method for separating total alkaloids of mulberry leaves with ion exchange resin. This technique does not yield deoxynojirimycin monomer.

Chinese patent technology (201010130263.6) reported a method for preparing flavonoids and alkaloids from mulberry leaves: flavonoids were extracted by heating with alkaline water, alkaloids were extracted by 90-95% ethanol and activated carbon, and the flavonoid extract was acid-adjusted and passed through a macroporous resin column , Acidification crystallization and 70-80% ethanol dissolution recrystallization, alkaloid extract concentration, acetone redissolution, aluminum peroxide short and thick column, ammoniated crystallization and 85-90% ethanol dissolution recrystallization. This technique requires a large amount of organic solvent, and deoxynojirimycin monomer is not obtained.

Chinese patent technology (201110021131.4) reports the preparation method of 1-deoxynojirimycin in mulberry leaves: the method of producing 1-deoxynojirimycin by high-voltage pulsed electric field technology, which improves product quality and production efficiency at the same time due to normal temperature extraction , reducing production costs. This technology did not obtain pure deoxynojirimycin.

Chinese patent technology (200910167602.5) reported a method for extracting and separating high-purity 1-deoxynojirimycin from natural products: raw material dry powder was extracted with a hydrophilic solvent, the extract was acidified and concentrated, soaked in anion exchange resin, and the effluent and washing liquid were concentrated Then use cation exchange column chromatography, organic solvent extraction, recrystallization, and gel column chromatography to purify. The 1-deoxynojirimycin content in the obtained product is not less than 98%. The specific implementation has entered the pilot test. This technology requires anion exchange resins and cation exchange resins, as well as various organic solvents such as alcohol, acetone, chloroform, butanol, especially chloroform, which is highly toxic; the extraction process requires multiple concentrations and high energy consumption.

Chinese patent technology (201110038204.0) reported a method of extracting and separating high-purity 1-deoxynojirimycin from mulberry leaves: extracting the raw material powder with an aqueous solvent, filtering off the medicinal residue, centrifuging the material to obtain an extract; concentrating the extract to no Ethanol, ultrafiltration membrane filtration; then use inorganic acid to adjust the pH to 3.0-4.0, precipitate, and centrifuge to remove impurities; acidify the feed liquid on a strong acid cationic resin column, wash with water, and then elute with ammonia water; feed the feed liquid on a macroporous resin column, Wash with water, then elute with ethanol gradients of different concentrations, collect the target eluent; concentrate the target eluent under reduced pressure, and dry to obtain the crude product; dissolve the crude product in absolute ethanol, remove impurities with an alkaline adsorption column, and collect the effluent; The effluent was concentrated under reduced pressure, crystallized and recrystallized at room temperature, and refined 1-DNJ was obtained. In the whole process of the invention, no other organic solvents are used except ethanol, the operation is safe, and the 1-DNJ content can reach 98.3%. This process requires the use of ultrafiltration technology, ethanol distributed elution, and the collection of the target eluent requires continuous detection of the effluent components, etc. The operation is complicated and the energy consumption is high.

So far, from the existing literature and patented technology, the extraction of pure deoxynojirimycin or the use of too much organic solvent, especially the use of chloroform, lead to low safety; or require multiple concentrations and high energy consumption ; or need to use too many steps, or need to detect and collect target components step by step, because deoxynojirimycin has no ultraviolet absorption, detection is more troublesome, complex operation, difficult to control industrial production; or can not get pure products, etc.

[1] Gross V, Andus T, Tran-ThiT A, et al. 1-Deoxynojirimycin in pairs oligo saccharide processing of α ₁ -proteinase inhibitor and inhibits its secretion in primary cultures of rat hepatocytes[J]. BiolChem, 1983, 258 (20):12203-12209.

[2] Yoshiaki Y. Inhibition of intestinal α-glucosidase activity and post prandial hyperglycem ia by moranoline and its N-alkyl derivatives[J]. Agric Biol Chem, 1988, 52(1):121-128.

[3] Yuan Aihong, Ma Jun, Jiang Xiaofeng, et al. Screening and in vitro activity study of glycosidase inhibitory components from mulberry leaves[J]. Journal of Tongji University: Medical Edition, 2005,26(4):8-11.

[4] Oku T, YamadaM, Nakamura M, et al. Inhibitory effects of extractives from leaves of Morus alba on human and rat small intestinal carbohydrates activity[J]. J Nutr, 2006, 95(5):933-938.

[5] Peng Zhongtian, Shen Cui, Tan Deming, et al. In vitro study on deoxynojirimycin derivatives against hepatitis B virus[J]. Chinese Pharmacy, 2007, 18(1):22-24.

[6] Tsuruka T, FukuyasuH. Inhibition of mouse tum or metastas is with nojirimycin—related compounds[J]. J Antibiot, 1996, 49(2):155-161.

[7] Zhou Xiaoling, Sun Lingyun, Zhang Jin, Yin Hao, Cui Weizheng. Research progress on the source and synthesis of deoxynojirimycin. Sericulture Science. 2011, 37(1): 0105-0111.

[8] Li Yuliang, Li Jianmin, Wu Yarui. Study on extraction and separation method of deoxynojirimycin. Applied Chemicals. 2006,35(9):599～661.

[9] Liu Weijun, Zhao Jun, Gao Xiumei, Liu Meiping, Zeng Sen. 1-Deoxynojirimycin extraction and refining process research. Chinese Journal of Traditional Chinese Medicine. 2009, 27 (10): 2079-2081.

[10] Zhou Huiyan, Hu Xiaoyu, Ma Ying. Purification and determination of deoxynojirimycin in mulberry leaves. Chinese Journal of Modern Applied Pharmacy, 2008, 25(5): 367-368.

[11] Liu Shuxing, Hua Junli, Ma Wenjin. Purification of 1-deoxynojirimycin (DNJ) by resin method. food tech. 2009, 34 (7): 168-170.

Contents of the invention

Aiming at the deficiencies of the existing deoxynojirimycin monomer extraction technology, the purpose of the present invention is to provide an extraction method for deoxynojirimycin (DNJ) monomer, which can realize the extraction and separation of DNJ, and has a simple process, saves energy, and has no Pollution, recycling, easy implementation, adaptable to large-scale production, low cost, high extraction efficiency and good product purity.

The extraction method of DNJ monomer of the present invention, comprises the steps:

(1) The mulberry raw material is extracted 1 to 3 times with 2 to 10 times (w/v) acid water (0 to 5% w/v) or aqueous solution (room temperature to 100°C), each time for 0.1 to 48 hours;

(2) The extract is adsorbed with a cation exchange resin with a volume ratio of 0.1 to 1 (v/v), washed with water at a volume ratio of 1 to 10 times the volume (v/v) of the cation exchange resin, and then washed with 1 to 10 times the volume of the cation exchange resin. Volume (v/v) of ammonia water (0.05～2mol/L) for elution;

(3) After pre-concentrating the ammonia water eluent by reverse osmosis 2 to 20 times, distill and recover ammonia to obtain intermediate A; the recovered ammonia water is used for the elution of (2);

(4) Intermediate A is dissolved in a hydrophilic solvent and prepared as a 1-20% (w/v) solution, and the catalytic conversion is carried out for 1 hour, and the gel layer is formed according to the volume ratio of gel:solution of 1-10:1 Analysis column, hydrophilic solvent elution;

(5) After recovering the solvent, intermediate B is obtained. Intermediate B is dissolved in a mixed solvent and prepared into a solution of 1-20% (w/v), and chromatographically performed according to the volume ratio of adsorbent:solution of 1-10:1 column, solvent elution; the recovered hydrophilic solvent is used for the elution of (4);

(6) Recover the solvent and dry it in vacuum to obtain pure deoxynojirimycin; the recovered solvent is used for the elution of (5).

This process technology can obtain pure deoxynojirimycin of various purity levels such as 10%, 50%, 90%, 99%.

Further, the mulberry raw material in the process step (1) refers to one or more of mulberry branches, mulberry leaves, and white cortex; acid water refers to sulfuric acid or hydrochloric acid aqueous solution; soaking refers to soaking at room temperature to 100°C. Energy consumption is reduced due to soaking at room temperature.

Further, the cation exchange resin in step (2) of this process refers to common strongly acidic or weakly acidic cation exchange resins, including: 732, 7320, 001, D001, 110, 122, D113, D151, 724 and other cation exchange resins . The extract is directly applied to the cation exchange resin without any treatment, which greatly saves the cost and eliminates the environmental protection problem.

Further, the reverse osmosis technology in step (3) of this process pre-concentrates the ammonia water eluent; the reverse osmosis technology used in this process is a common reverse osmosis technology. This technology enriches ammonia and DNJ while concentrating ammonia solution, which greatly reduces the energy consumption of conventional concentration, which is the key to energy saving.

Further, the catalytic conversion in step (4) of this process refers to catalytic conversion with a catalyst (0.01-1% W/V hydrochloric acid or sulfuric acid) at 60-100°C before applying the gel chromatography column; The chromatographic column refers to Superose, Sephdex LH-20, Hitrap SP, sephodex, etc.; the hydrophilic solvent refers to water, methanol, ethanol, acetone, etc. The present invention adopts catalytic conversion, which is the key to not needing to monitor intermediates during chromatography, and is also the key to increasing the yield.

Further, the chromatographic column in the process step (5) refers to calcium oxide, aluminum hydroxide, silica gel, activated carbon, aluminum oxide, etc.; the solvent refers to methanol-ethyl acetate, ethanol-ethyl acetate, acetone- Ethyl acetate, etc.

The beneficial effects of the present invention are:

The extraction method of DNJ monomer of the present invention uses at least one of mulberry leaves, mulberry branches, and cortex Morus alba as a raw material, and combines the physical and chemical characteristics of various components of DNJ to extract the raw materials at room temperature to 100°C, and the extract is directly The cation exchange resin is enriched, and the DNJ ammonia solution eluted with ammonia water is pre-concentrated and enriched by reverse osmosis technology, which greatly reduces energy consumption; the intermediate is catalytically converted, and the product is directly collected during chromatography without monitoring operations. The energy consumption of the whole operation process is very low, which greatly saves energy compared with the traditional process.

The ammonia in the ammonia solution used to elute the DNJ on the cation exchange resin in the present invention is recovered and recycled; the hydrophilic solvent for eluting the gel column and the mixed solvent for eluting the chromatographic column are all recycled. The whole process is energy-saving and environment-friendly, and realizes the recycling of the extraction solvent.

The elution solvent and intermediate catalytic conversion technology selected by the present invention automatically realize graded elution, each of the three separations does not need intermediate monitoring, and the production technology is easy to master. The purity of the obtained product can be controlled at four levels: 10%, 50%, 90%, and 99%. It can meet the raw materials of hypoglycemic drugs and anticancer drugs, can also be used as a reference substance, and can also be used as raw materials for other products.

Detailed ways

Preferred embodiments of the present invention will be described in detail below. It should be understood that the preferred embodiments are only for illustrating the present invention, but not for limiting the protection scope of the present invention.

Example 1

(1) Soak 1 kg of mulberry branches in 10 liters of 0.1% (w/v) sulfuric acid solution at room temperature for 48 hours; filter to obtain an extract (about 9 liters).

(2) 9 liters of the extract was stirred and adsorbed with 0.9 liters of pretreated 732 cation exchange resin, then, the resin was washed with 0.9 liters of water, and then washed with 0.9 liters of 2mol/L ammonia water. About 0.9 liters of ammonia eluate was obtained.

(3) After 0.9 liters of ammonia water eluate was concentrated twice by reverse osmosis (about 0.45 liters of concentrated solution), ammonia was recovered by distillation to obtain intermediate A (about 10 grams); the recovered ammonia water was used for the elution of (2).

(4) Intermediate A was dissolved in water and prepared into a 20% solution (about 50 ml), added 0.01% hydrochloric acid (w/v) at 100°C for 1 hour under reflux conversion, and put on a 50 ml Superose gel chromatography column, Elute with water; collect eluate.

(5) After recovering the solvent, intermediate B was obtained. Intermediate B (about 1 g) was dissolved in 5 ml of methanol-ethyl acetate (1:1) mixed solvent, and the solution was placed on a 5-gram silica gel column, and methanol-ethyl acetate ( 1:1) mixed solvent elution.

(6) Recover the solvent and dry it in vacuum to obtain pure deoxynojirimycin. The purity of deoxynojirimycin is 99%.

Example 2

(1) Soak 1Kg of mulberry leaves in 2 liters of 5% (w/v) hydrochloric acid solution at 100°C for 0.1 hour, filter to obtain the extract (about 1 liter); then use 2 liters of 0.5% (w/v) hydrochloric acid solution for the residue Soak in hydrochloric acid solution at 100°C for 0.1 hour, filter to obtain an extract (about 1 liter); soak the residue in 2 liters of water at 100°C for 0.1 hour, filter to obtain an extract (about 1 liter). The three extracts were combined to obtain about 3 liters of extract.

(2) 3 liters of extract was stirred and adsorbed with 3 liters of pretreated 001 cation exchange resin, then, the resin was washed with 30 liters of water, and then washed with 30 liters of 0.05mol/L ammonia water. About 30 liters of ammonia eluent was obtained.

(3) After the 30 liters of ammonia water eluate was concentrated 20 times by reverse osmosis (about 1.5 liters of concentrated solution), the ammonia was recovered by distillation to obtain intermediate A (about 20 grams); the recovered ammonia water was used for the elution of (2).

(4) Intermediate A was dissolved in methanol and prepared as a 1% solution (about 2000 ml), added 1% sulfuric acid (w/v) at 60°C for 1 hour, and then 20,000 ml of Sephdex LH-20 gel layer was applied Analyze the column and elute with methanol; collect the eluate.

(5) After recovering the solvent, intermediate B was obtained. Intermediate B (about 1 g) was dissolved in 100 ml of ethanol-ethyl acetate (1:1), and the solution was placed on a 1000 g column of aluminum oxide, ethanol-ethyl acetate ( 1:1) elution.

(6) Recover the solvent and dry it in vacuum to obtain pure deoxynojirimycin. The purity of deoxynojirimycin is 50%.

Example 3

(1) Soak 1Kg of Morus alba cortex with 5 liters of 1% (w/v) sulfuric acid solution at 60°C for 5 hours, filter to obtain the extract (about 3 liters); use 5 liters of 1% (w/v) for the residue The sulfuric acid solution was soaked at 60°C for 5 hours, and filtered to obtain an extract (about 4 liters). The secondary extracts were combined to obtain about 7 liters of extracts.

(2) 7 liters of the extract was stirred and adsorbed with 3.5 liters of pretreated D151 cation exchange resin, then, the resin was washed with 7 liters of water, and then washed with 7 liters of 0.5mol/L ammonia water. About 7 liters of ammonia eluate was obtained.

(3) After the 7 liters of ammonia water eluate was concentrated by reverse osmosis 10 times (about 0.7 liters of concentrated solution), the ammonia was recovered by distillation to obtain intermediate A (about 30 grams); the recovered ammonia water was used for the elution of (2).

(4) Intermediate A was dissolved in ethanol and prepared into a 10% solution (about 300 ml), added 0.1% sulfuric acid (w/v) and incubated at 75°C for 1 hour, and applied to a 1500 ml Hitrap SP gel chromatography column , and elute with ethanol; collect the eluate.

(5) After recovering the solvent, Intermediate B (about 5 grams) was dissolved in 50 ml of acetone-ethyl acetate (1:1), and the solution was applied to a 250-gram activated carbon column, and acetone-ethyl acetate (1:1) was eluted.

(6) Recover the solvent and dry it in vacuum to obtain pure deoxynojirimycin. The purity of deoxynojirimycin is 10%.

Example 4

(1) Soak 1 kg of mulberry branches in 6 liters of water at 90°C for 12 hours, filter to obtain an extract (about 4 liters); soak the residue in 4 liters of water at 90°C for 12 hours, and filter to obtain an extract (about 3 liters). The secondary extracts were combined to obtain about 7 liters of extracts.

(2) 7 liters of extract was stirred and adsorbed with 1.4 liters of pretreated 122 cation exchange resin, then, the resin was washed with 2.8 liters of water, and then washed with 2.8 liters of 0.1mol/L ammonia water. About 2.8 liters of ammonia eluate was obtained.

(3) After the 2.8 liters of ammonia water eluate was concentrated by reverse osmosis for 5 times (about 0.6 liters of concentrated solution), ammonia was recovered by distillation to obtain intermediate A (about 10 grams); the recovered ammonia water was used for the elution of (2).

(4) Intermediate A was dissolved in acetone and prepared into a 5% solution (about 200 ml), added 0.2% hydrochloric acid (w/v) at 60°C for 1 hour, and put on a 200 ml sephodex gel chromatography column, Elute with acetone; collect the eluate.

(5) After recovering the solvent, Intermediate B was obtained. Intermediate B (about 2 grams) was dissolved in 40 ml of methanol-ethyl acetate (1:1), and the solution was placed on an 80-gram calcium oxide column, methanol-ethyl acetate (1:1) 1) Elution.

(6) Recover the solvent and dry it in vacuum to obtain pure deoxynojirimycin. The purity of deoxynojirimycin is 90%.

Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention without limitation. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (8)

1. an extraction method of deoxynojirimycin monomer, characterized in that: comprise the steps: (1) The mulberry raw material is soaked and extracted with 2-10 times w/v acid solution or water for 1-3 times, each time for 0.1-48 hours; (2) Adsorb the extract with 0.1 to 1 times the volume of cation exchange resin; wash with water 1 to 10 times the volume of cation exchange resin, and finally elute with ammonia water 1 to 10 times the volume of cation exchange resin; (3) After pre-concentrating the ammonia water eluent by reverse osmosis 2 to 20 times, distill and recover ammonia to obtain intermediate A; (4) Intermediate A is dissolved in a hydrophilic solvent and prepared into a solution of 1-20% w/v, catalytically converted for 1 hour, and put on a gel chromatography column according to the volume ratio of gel:solution of 1-10:1 , hydrophilic solvent elution; (5) Intermediate B is obtained after solvent recovery, and intermediate B is dissolved in a mixed solvent to prepare a solution of 1-20% w/v, and the volume ratio of adsorbent:solution is 1-10:1 and put on the chromatographic column , solvent elution; (6) Recover the solvent and dry it in vacuum to obtain pure deoxynojirimycin. 2. The extraction method of deoxynojirimycin monomer according to claim 1, characterized in that: the mulberry raw material in step (1) refers to one or more of mulberry branches, mulberry leaves, and white cortex of Morus alba; Water refers to sulfuric acid or hydrochloric acid aqueous solution, the concentration of which is ≥0 and ≤5%; soaking refers to soaking at room temperature to 100°C. 3. The method for extracting deoxynojirimycin monomer according to claim 1, characterized in that: the cation exchange resin in step (2) refers to common strongly acidic or weakly acidic cation exchange resin, select 732, 7320, 001 , D001, 110, 122, D113, D151, 724. 4. The method for extracting deoxynojirimycin monomer according to claim 1, characterized in that the concentration of ammonia water in step (2) is 0.05-2 mol/L. 5. The method for extracting deoxynojirimycin monomer according to claim 1, characterized in that: the catalytic conversion in step (4) refers to the use of 0.01 to 1% w/ The hydrochloric acid or sulfuric acid of v is used as a catalyst to catalyze the transformation at 60-100°C; the gel chromatography column is selected from Superose, Sephdex LH-20, Hitrap SP, and sephodex; the hydrophilic solvent refers to water, methanol, ethanol or acetone. 6. The method for extracting deoxynojirimycin monomer according to claim 1, characterized in that: the chromatographic column in step (5) refers to calcium oxide, aluminum hydroxide, silica gel, activated carbon or aluminum oxide; Said mixed solvent refers to methanol-ethyl acetate, ethanol-ethyl acetate or acetone-ethyl acetate. 7. The method for extracting deoxynojirimycin monomer according to any one of claims 1-7, characterized in that: the ammonia water recovered in step (3) is used for the elution of the second step (2); step ( 5) The recovered hydrophilic solvent is used for the elution of step (4); the recovered solvent of step (6) is used for the elution of step (5). 8. according to the extraction method of the described deoxynojirimycin monomer of any one of claim 1-6, it is characterized in that: this extraction method can obtain 10%, 50%, 90%, 99% various purity levels Pure deoxynojirimycin.