A method for preparing yohimbine by using supercritical extraction combined with cooking technology

Abstract

The present invention relates to a method for preparing yohimbine by using supercritical extraction combined with steaming technology. The method solves the technical problems of incomplete extraction of existing yohimbine, low yield, complex process, long production cycle, high cost, and unsuitability for industrial production. The present invention relates to a method for preparing yohimbine by using supercritical extraction combined with steaming technology, comprising the following steps: 1) crushing the raw material, heating and steaming; 2) performing supercritical gradient extraction, extracting twice in total, and collecting the second supercritical extraction paste; 3) adding a mixed solvent to the second supercritical extraction paste, stirring, filtering and collecting the precipitate; 4) using an organic solvent to heat dissolve the precipitate, adding an adsorbent for adsorption, filtering and collecting the filtrate, concentrating the filtrate and standing it until the crystals are completely precipitated, filtering and collecting the crystals again, rinsing and drying the crystals in sequence, and obtaining yohimbine.

Description

Technical Field

[0001] The invention relates to a method for preparing yohimbine by adopting supercritical extraction combined with steaming technology. Background Art

[0002] Yohimbe trees mainly grow in tropical areas on the west coast of Africa. The total alkaloid content in yohimbine bark is as high as 6.1%, mainly indole alkaloids, among which yohimbine has the most outstanding biological activity. Studies have shown that yohimbine has a unique health-care effect, which can selectively block α2 adrenergic receptors, excite sympathetic nerves and increase the secretion of norepinephrine. In addition to being used to treat male sexual dysfunction, it can also be used to treat diseases such as arteriosclerosis and rheumatism. It also has pharmacological functions such as lowering blood pressure, anti-depression, inhibiting skin melanin production, weight loss and anti-psychotic.

[0003] Chinese patent application number 202010506337.5 discloses a method for extracting yohimbine from yohimbe bark. The raw material is first enzymatically hydrolyzed with cellulase, and then ethanol extraction, concentration, and precipitate collection are performed in sequence. Then, acid dissolution and alkali precipitation are used, and yohimbine is obtained by recrystallization.

[0004] Chinese patent application number 201010541739.5 discloses a method for extracting yohimbine from yohimbe bark. The raw material is first ultrasonically extracted with sulfuric acid and ethanol, and then concentrated, ultrafiltered, separated with macroporous adsorption resin, eluted with acid and alcohol for effective components, concentrated, simplified with ammonia water, and recrystallized with anhydrous ethanol.

[0005] Chinese patent application number 201110188916.0 discloses a method for extracting yohimbine hydrochloride from yohimbe bark, which comprises the following steps: heating the raw material with hydrochloric acid and ethanol for extraction, adsorbing it with a macroporous resin, eluting it with ethanol, concentrating and drying it, then dissolving it with ethanol or methanol, decolorizing it with activated carbon or neutral alumina, and allowing it to crystallize to obtain yohimbine hydrochloride.

[0006] Chinese patent application number 201010546258.3 discloses a method for extracting and separating yohimbine from the bark of the African yohimbe tree. The raw materials are extracted with methanol or ethanol, concentrated, precipitated, acid-dissolved and alkali-dissolved, precipitated and dissolved, decolorized with activated carbon or clay, concentrated, dissolved with an alkaline organic solvent, column chromatography, eluted with a mixed solvent, concentrated and crystallized, and recrystallized to obtain high-purity yohimbine.

[0007] Most of the above processes use column chromatography and acid-solution-alkali precipitation processes for separation and purification, and all have problems such as complex processes, long production cycles, low extraction rates, difficult purification, high costs, and unsuitability for industrial production. Summary of the invention

[0008] The invention aims to solve the technical problems of incomplete extraction of yohimbine, low yield, complex process, long production cycle, high cost, unsuitability for industrial production, etc., and to provide a method for preparing yohimbine by using supercritical extraction combined with steaming technology.

[0009] The technical solution of the present invention is:

[0010] A method for preparing yohimbine by using supercritical extraction combined with steaming technology is special in that it comprises the following steps:

[0011] 1) Steaming

[0012] The raw material is crushed and heated and steamed for 30-60 minutes; the raw material is yohimbe bark;

[0013] 2) Supercritical gradient extraction

[0014] The steamed raw materials are subjected to gradient extraction using supercritical fluid extraction technology, and the extraction is performed twice in total, and the second supercritical extraction paste is collected;

[0015] 3) Remove impurities

[0016] Add a mixed solvent in an amount of 5 to 15 times the mass of the second supercritical extraction paste to the second supercritical extraction paste, stir for several times, and filter and collect the precipitate;

[0017] 4) Refining

[0018] The precipitate is thermally dissolved by an organic solvent, an adsorbent is added for adsorption, the filtrate is collected by filtration, the filtrate is concentrated and then allowed to stand until crystals are completely precipitated, the crystals are collected by filtration again, and the crystals are rinsed and dried in sequence to obtain yohimbine.

[0019] Furthermore, in step 2), the gradient extraction is: using supercritical carbon dioxide superfluid for gradient extraction, firstly performing a first extraction on the cooked raw material at a pressure of 35MPa-40MPa and a temperature of 35-45°C, the extraction time is 30-60min, to obtain a first supercritical extraction paste, and discarding the first supercritical extraction paste, and then performing a second extraction at a pressure of 45MPa-55MPa and a temperature of 45-55°C, the extraction time is 60-120min, and collecting the second supercritical extraction paste.

[0020] Furthermore, in step 2), the second extraction needs to use an entrainer, the entrainer is ethyl acetate, and the amount of ethyl acetate used is 5%-15% of the mass of the raw material.

[0021] Furthermore, in step 3), the mixed solvent is a mixed solution of petroleum ether and ethyl acetate, wherein the volume ratio of petroleum ether to ethyl acetate is 5-8:1.

[0022] Furthermore, in step 3), the stirring times are 2 times, and each stirring time is 1-3 hours.

[0023] Furthermore, in step 4), the amount of the organic solvent is 8-15 times the mass of the precipitate; the organic solvent is a mixed solution of dichloromethane and methanol, wherein the volume ratio of dichloromethane to methanol is 20-30:1.

[0024] Furthermore, in step 4), the adsorbent is activated carbon, the amount of activated carbon used is 5%-20% of the mass of the precipitate, and the adsorption time is 2-4h.

[0025] Further, step 1) specifically comprises: crushing the yohimbe bark raw material, heating and steaming for 50 minutes;

[0026] Step 2) is specifically as follows: using supercritical carbon dioxide superfluid for gradient extraction, firstly extracting the cooked raw material at a pressure of 40 MPa and a temperature of 40° C. for 60 min to obtain a first supercritical extraction paste, and discarding the first supercritical extraction paste; then using ethyl acetate with a mass percentage of 10% of the raw material as an entrainer, performing a second extraction at a pressure of 45 MPa and a temperature of 50° C. for 100 min, and collecting the second supercritical extraction paste;

[0027] Step 3) is specifically as follows: adding a mixed solvent of petroleum ether and ethyl acetate in an amount 10 times the mass of the second supercritical extraction paste to the second supercritical extraction paste, wherein the volume ratio of petroleum ether to ethyl acetate is 6:1, stirring twice, each time stirring for 2 hours, and filtering and collecting the precipitate;

[0028] Step 4) is specifically as follows: adding 12 times the mass of the precipitate of dichloromethane-methanol, the volume ratio of dichloromethane to methanol is 25:1, heating to dissolve, adding 10% of the mass of the precipitate of activated carbon for adsorption for 4 hours, filtering and collecting the filtrate, concentrating the filtrate and letting it stand until the crystals are completely precipitated, filtering and collecting the crystals again, washing the crystals with water and drying them in turn to obtain yohimbine.

[0029] The beneficial effects of the present invention are:

[0030] 1. The present invention discloses a method for preparing yohimbine by adopting supercritical extraction combined with cooking technology. The supercritical extraction technology combined with cooking technology is used for yohimbine bark raw material. Since yohimbine has good stability, the steam generated during the cooking process has strong penetrating power, which can destroy the cell wall in the raw material, hydrate the macromolecular substances, degrade the heat-sensitive substances, improve the subsequent supercritical extraction rate, avoid incomplete extraction caused by direct extraction with traditional solvents, or increase of impurities caused by alkali extraction, simplify the process steps, effectively solve the two major problems of low yohimbine extraction rate and difficult purification, and the extraction rate is improved by about 15% compared with the traditional method.

[0031] 2. The present invention discloses a method for preparing yohimbine by using supercritical extraction combined with cooking technology. According to the difference in molecular weight and polarity between yohimbine and other fat-soluble impurities and their different solubilities in supercritical CO2, a gradient extraction technology is used to selectively extract and separate yohimbine, thereby achieving separation of yohimbine and providing a good foundation for subsequent purification and identification.

[0032] 3. The present invention discloses a method for preparing yohimbine by using supercritical extraction combined with cooking technology. The supercritical extraction paste is stirred and impurized by using a mixed solvent of petroleum ether and ethyl acetate, so that small polar impurities generated by supercritical extraction can be further removed, thereby significantly improving the content of yohimbine.

[0033] 4. The present invention discloses a method for preparing yohimbine by using supercritical extraction combined with steaming technology. This process can replace the traditional yohimbine purification process, is simple and easy to operate, can effectively shorten the production cycle, and is suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a liquid phase spectrum obtained in Example 1 of a method for preparing yohimbine using supercritical extraction combined with cooking technology of the present invention;

[0035] Figure 2 This is a liquid phase spectrum obtained in Example 2 of a method for preparing yohimbine using supercritical extraction combined with cooking technology of the present invention;

[0036] Figure 3 This is a liquid phase spectrum obtained in Example 3 of a method for preparing yohimbine using supercritical extraction combined with cooking technology of the present invention;

[0037] Figure 4 This is a liquid phase spectrum obtained in Example 4 of a method for preparing yohimbine using supercritical extraction combined with cooking technology of the present invention;

[0038] Figure 5 This is the liquid phase spectrum obtained in Example 5 of the method for preparing yohimbine using supercritical extraction combined with cooking technology of the present invention. DETAILED DESCRIPTION

[0039] In order to make the above-mentioned objects and advantages of the present invention more obvious and easy to understand, the method of the present invention is described in detail below with reference to the embodiments and drawings. The present invention uses yohimbe bark as raw material.

[0040] Example 1

[0041] 1) Steaming: Crush 10 kg of raw materials and steam for 50 min.

[0042] 2) Supercritical gradient extraction: The raw material after cooking in step 1) is subjected to supercritical carbon dioxide superfluid gradient extraction, firstly, the first extraction is carried out at a pressure of 40 MPa and a temperature of 40° C., the extraction time is 60 min, and the first supercritical extraction paste is obtained, and the first supercritical extraction paste is discarded; then, ethyl acetate is used as an entrainer, and a second extraction is carried out at a pressure of 45 MPa and a temperature of 50° C., the extraction time is 100 min, and the amount of ethyl acetate used is 10% of the mass of the raw material, to obtain a second supercritical extraction paste.

[0043] 3) Impurity removal: add a mixed solvent of petroleum ether and ethyl acetate in an amount 10 times its mass to the second supercritical extraction paste in step 2), the volume ratio of petroleum ether to ethyl acetate is 6:1, stir twice, each time for 2 hours, filter, and collect the precipitate.

[0044] 4) Purification: Add 12 times the mass of the precipitate to the precipitate obtained in step 3) in the amount of dichloromethane-methanol, the volume ratio of dichloromethane to methanol is 25:1, heat to dissolve, add 10% of the mass of the precipitate in activated carbon for adsorption for 4 hours, filter, concentrate the obtained filtrate and let it stand until the crystals are completely precipitated, filter and collect the crystals again, rinse the crystals with warm water at 40°C-60°C, dry, and obtain 94.1g of product. Liquid phase detection is performed, and the yohimbine content is measured to be 99.3%. The liquid phase spectrum is as follows Figure 1 shown.

[0045] Example 2

[0046] 1) Steaming: Crush 10 kg of raw materials and steam for 30 min.

[0047] 2) Supercritical extraction: The raw material after cooking in step 1) is subjected to gradient extraction using supercritical carbon dioxide superfluid, firstly extracted at a pressure of 35 MPa and a temperature of 45° C. for 50 min to obtain a first supercritical extraction paste, and the first supercritical extraction paste is discarded; then ethyl acetate is used as an entrainer, extracted at a pressure of 55 MPa and a temperature of 45° C. for 120 min, and the amount of ethyl acetate used is 5% of the mass of the raw material, to obtain a second supercritical extraction paste.

[0048] 3) impurity removal: add a mixed solvent of petroleum ether and ethyl acetate in an amount of 5 times the mass of the second supercritical extraction paste in step 2), wherein the volume ratio of petroleum ether to ethyl acetate is 5:1, stir twice, each time for 1 hour, filter, and collect the precipitate.

[0049] 4) Purification: Add 8 times the mass of the precipitate to the precipitate obtained in step 3) with a volume ratio of 20:1 of dichloromethane-methanol, heat to dissolve, add 5% of the mass of the precipitate with activated carbon for adsorption for 4 hours, filter, concentrate the filtrate, and let it stand until the crystals are completely precipitated, filter and collect the crystals again, rinse the crystals with warm water, and dry to obtain 92.7g of product. The liquid phase detection shows that the yohimbine content is 98.5%. The liquid phase spectrum is as shown in Figure 2 shown.

[0050] Example 3

[0051] 1) Steaming: Crush 10 kg of raw materials and steam for 60 min.

[0052] 2) Supercritical extraction: The raw material after cooking in step 1) is subjected to gradient extraction using supercritical carbon dioxide superfluid, firstly extracted at a pressure of 40 MPa and a temperature of 35° C. for 30 min to obtain a first supercritical extraction paste, and the first supercritical extraction paste is discarded; then ethyl acetate is used as an entrainer, extracted at a pressure of 45 MPa and a temperature of 45° C. for 60 min, and the amount of ethyl acetate used is 15% of the mass of the raw material, to obtain a second supercritical extraction paste.

[0053] 3) impurity removal: add a mixed solvent of petroleum ether and ethyl acetate in an amount 15 times the mass of the second supercritical extraction paste in step 2), wherein the volume ratio of petroleum ether to ethyl acetate is 8:1, stir twice, each time for 3 hours, filter, and collect the precipitate.

[0054] 4) Purification: Add 15 times the mass of the precipitate to the precipitate obtained in step 3) in the amount of dichloromethane-methanol, the volume ratio of dichloromethane to methanol is 30:1, heat to dissolve, add 20% of the mass of the precipitate in activated carbon for adsorption for 2 hours, filter, concentrate the obtained filtrate and let it stand until the crystals are completely precipitated, filter and collect the crystals again, rinse the crystals with warm water, and dry to obtain 93.8g of product. The liquid phase detection measured the yohimbine content to be 98.4%. The liquid phase spectrum is as follows Figure 3 shown.

[0055] Example 4

[0056] 1) Steaming: Crush 10 kg of raw materials and steam for 50 min.

[0057] 2) Supercritical extraction: The raw material after cooking in step 1) is subjected to gradient extraction using supercritical carbon dioxide superfluid, firstly extracted at a pressure of 35 MPa and a temperature of 35° C. for 60 min to obtain a first supercritical extraction paste, and the first supercritical extraction paste is discarded; then ethyl acetate is used as an entrainer, extracted at a pressure of 55 MPa and a temperature of 55° C. for 60 min, and the amount of ethyl acetate used is 8% of the mass of the raw material, to obtain a second supercritical extraction paste.

[0058] 3) Impurity removal: add a mixed solvent of petroleum ether and ethyl acetate in an amount of 8 times the mass of the second supercritical extraction paste in step 2), the volume ratio of petroleum ether to ethyl acetate is 7:1, stir twice, each time for 2.5 hours, filter, and collect the precipitate.

[0059] 4) Purification: Add 10 times the mass of the precipitate to the precipitate obtained in step 3) in the amount of dichloromethane-methanol, the volume ratio of dichloromethane to methanol is 28:1, heat to dissolve, add 15% of the mass of the precipitate in activated carbon for adsorption for 2.5 hours, filter, concentrate the filtrate and let it stand until the crystals are completely precipitated, filter and collect the crystals again, rinse the crystals with warm water, and dry to obtain 91.7g of product. The liquid phase detection measured the yohimbine content to be 99.0%, and the liquid phase spectrum is as shown in Figure 4 shown.

[0060] Example 5

[0061] 1) Steaming: Crush 10 kg of raw materials and steam for 40 min.

[0062] 2) Supercritical extraction: The raw material after cooking in step 1) is subjected to gradient extraction using supercritical carbon dioxide superfluid, firstly extracted at a pressure of 38 MPa and a temperature of 40° C. for 40 min to obtain a first supercritical extraction paste, and the first supercritical extraction paste is discarded; then ethyl acetate is used as an entrainer, extracted at a pressure of 46 MPa and a temperature of 50° C. for 80 min, and the amount of ethyl acetate used is 12% of the mass of the raw material, to obtain a second supercritical extraction paste.

[0063] 3) Impurity removal: add a mixed solvent of petroleum ether and ethyl acetate in an amount 12 times the mass of the second supercritical extraction paste in step 2), the volume ratio of petroleum ether to ethyl acetate is 6:1, stir twice, each time for 2 hours, filter, and collect the precipitate.

[0064] 4) Purification: Add 9 times the mass of the precipitate to the precipitate obtained in step 3) in the amount of dichloromethane-methanol, the volume ratio of dichloromethane to methanol is 22:1, heat to dissolve, add 8% of the mass of the precipitate in activated carbon for adsorption for 3.5 hours, filter, concentrate the obtained filtrate and let it stand until the crystals are completely precipitated, filter and collect the crystals again, rinse the crystals with warm water, and dry to obtain 92.8g of product. The liquid phase detection measured the yohimbine content to be 98.2%. The liquid phase spectrum is as follows Figure 5 shown.

Claims

1. A method for preparing yohimbine using supercritical extraction combined with cooking technology, characterized in that: The following steps are involved: 1) Steaming The raw material is crushed and heated and steamed for 30-60 minutes; the raw material is yohimbe bark; 2) Supercritical gradient extraction The steamed raw materials were subjected to gradient extraction using supercritical fluid extraction technology, and the extraction was performed twice, and the second supercritical extraction paste was collected; specifically: Supercritical carbon dioxide superfluid is used for gradient extraction. The steamed raw material is first extracted at a pressure of 35MPa-40MPa and a temperature of 35-45°C for 30-60min to obtain a first supercritical extraction paste, which is discarded. Then, a second extraction is performed at a pressure of 45MPa-55MPa and a temperature of 45-55°C for 60-120min to collect the second supercritical extraction paste. The second extraction requires an entrainer. The entrainer is ethyl acetate, and the amount of ethyl acetate is 5%-15% of the mass of the raw material. 3) Remove impurities Adding a mixed solvent in an amount 5-15 times the mass of the second supercritical extraction paste to the second supercritical extraction paste, stirring for multiple times, and filtering to collect the precipitate; the mixed solvent is a mixed solution of petroleum ether and ethyl acetate, wherein the volume ratio of petroleum ether to ethyl acetate is 5-8:1; 4) Refining The precipitate is thermally dissolved by an organic solvent, an adsorbent is added for adsorption, the filtrate is collected by filtering, the filtrate is concentrated and then allowed to stand until crystals are completely precipitated, the crystals are collected by filtering again, and the crystals are rinsed and dried in sequence to obtain yohimbine; the organic solvent is a mixed solution of dichloromethane and methanol, wherein the volume ratio of dichloromethane to methanol is 20-30:1; and the adsorbent is activated carbon.

2. The method for preparing yohimbine by supercritical extraction combined with cooking technology according to claim 1, characterized in that: In step 3), the stirring times are 2 times, each time for 1-3 hours.

3. The method for preparing yohimbine by supercritical extraction combined with cooking technology according to claim 2, characterized in that: In step 4), the amount of the organic solvent used is 8-15 times the mass of the precipitate.

4. The method for preparing yohimbine by supercritical extraction combined with cooking technology according to claim 3, characterized in that: In step 4), the amount of activated carbon used is 5%-20% of the precipitate mass, and the adsorption time is 2-4h.

5. The method for preparing yohimbine by supercritical extraction combined with cooking technology according to claim 4, characterized in that: Step 1) specifically comprises: crushing the yohimbe bark raw material, heating and steaming for 50 minutes; Step 2) is specifically as follows: using supercritical carbon dioxide superfluid for gradient extraction, firstly extracting the cooked raw material for the first time at a pressure of 40 MPa and a temperature of 40°C for 60 minutes, obtaining a first supercritical extraction paste, and discarding the first supercritical extraction paste; then using ethyl acetate with a mass percentage of 10% of the raw material as an entrainer, performing a second extraction at a pressure of 45 MPa and a temperature of 50°C for 100 minutes, and collecting the second supercritical extraction paste; Step 3) is specifically as follows: adding a mixed solvent of petroleum ether and ethyl acetate in an amount 10 times the mass of the second supercritical extraction paste to the second supercritical extraction paste, wherein the volume ratio of petroleum ether to ethyl acetate is 6:1, stirring twice, each time for 2 hours, and filtering and collecting the precipitate; Step 4) is specifically as follows: adding 12 times the mass of the precipitate of dichloromethane-methanol, the volume ratio of dichloromethane to methanol is 25:1, heating to dissolve, adding 10% of the mass of the precipitate of activated carbon for adsorption for 4 hours, filtering and collecting the filtrate, concentrating the filtrate and letting it stand until the crystals are completely precipitated, filtering and collecting the crystals again, washing the crystals with water and drying them in turn to obtain yohimbine.

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