A method for extracting and purifying abamectin

Abstract

The present application relates to a kind of extraction and purification method of abamectin, comprising the following steps: step 1, leaching: to the mycelium of Streptomyces avermitilis, organic solvent is added and leached, and the extract is collected;Step 2, impurity removal: after the extract is filtered, it is concentrated to 50% of the original extract volume after evaporation, the precipitate is removed by centrifugation, and the supernatant is obtained;Step 3, evaporation and concentration: the supernatant is continuously evaporated and concentrated, and the abamectin paste is obtained;Step 4, desugar: after the abamectin paste is desugared, the abamectin product after desugar is obtained;Step 5, crystallization: after adding crystallization solvent to the abamectin product after desugar, crystallization is carried out, solid-liquid separation is carried out, and the crystal is washed, and the abamectin finished product is obtained.The present application only needs to crystallize once to obtain the required abamectin finished product, reduces the crystallization times of abamectin, improves the production efficiency, and the yield of abamectin is improved, and the production cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biological pesticides, in particular to an extraction and purification method of avermectin. BACKGROUND

[0002] Avermectin is a kind of macrolide antibiotic produced by fermentation of Streptomyces avermitilis, which has strong insecticidal activity and is widely used as an agricultural or veterinary insecticide and acaricide. It has a broad insecticidal spectrum and has strong insecticidal activity against almost all insects and mites and animal parasites. At the same time, this avermectin is easily degradable in soil and water and has no accumulation and persistent residues in the body, so it will not pollute the environment. Therefore, it has great potential for development.

[0003] At present, the extraction and purification of avermectin is usually carried out by soaking the mycelium with an organic solvent, evaporating and concentrating the extract into a paste, dissolving the paste with toluene, washing with hot water to remove sugar, then adding water and removing the toluene by evaporation to realize the replacement of toluene and water, and then crystallizing at least 4 times to obtain the finished avermectin product. The problem is that there are too many impurities in the avermectin, which requires multiple crystallization to prepare the required avermectin product, and the yield of avermectin is reduced with each crystallization, and the more the number of crystallization, the more the energy consumption and the longer the time, which seriously affects the production efficiency and the yield of avermectin. SUMMARY

[0004] The present application aims to overcome the defects of the prior art and provide an extraction and purification method of avermectin, which can obtain the required avermectin product by only one crystallization, reduce the number of crystallization of avermectin, improve the production efficiency and the yield of avermectin, and reduce the production cost.

[0005] In order to achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] Technical scheme one:

[0007] An extraction and purification method of avermectin, comprising the following steps:

[0008] Step 1, soaking: adding an organic solvent to the mycelium of Streptomyces avermitilis for extraction, and collecting the extract;

[0009] Step 2, impurity removal: filtering the extract, evaporating and concentrating to 50% of the original extract volume, and then centrifuging to remove the precipitate to obtain the supernatant;

[0010] Step 3, evaporation and concentration: continuing to evaporate and concentrate the supernatant to obtain an avermectin paste;

[0011] Step 4, sugar removal: treating the avermectin paste to remove sugar to obtain an avermectin product after sugar removal;

[0012] Step 5, crystallization: after adding a crystallization solvent to the deglucosated avermectin product for crystallization, solid-liquid separation, and washing the crystals, an avermectin finished product is obtained.

[0013] Further, the preparation method of the Streptomyces avermitilis mycelium is as follows: after the Streptomyces avermitilis fermentation liquor is subjected to solid-liquid separation, the mycelium is blown dry for 20-30 min, crushing is started, and hot air drying is performed while crushing until the moisture content of the mycelium is ≤40%, and the mycelium is ready for use.

[0014] Further, in step 1, the organic solvent includes one or more of methanol, ethanol, acetone, and acetonitrile; and when the organic solvent is used for extraction, the mass ratio of the material to the liquid is 1:100-120.

[0015] In step 1, the organic solvent is used for extraction for at least 3 times.

[0016] Further, in step 2, multi-effect evaporation concentration is used for evaporation concentration; and in step 2, an anti-explosion disc centrifuge is used for centrifugation.

[0017] In step 3, when the supernatant is continuously subjected to evaporation concentration, the evaporation concentration is ended when the temperature is 80-82℃ and the vacuum degree reaches -0.08- -0.082 MPa.

[0018] Further, in step 4, the deglucosation is performed by using a toluene deglucosation method.

[0019] Further, the deglucosation treatment includes the following steps:

[0020] Toluene is added to the avermectin paste, and after stirring and dissolving, the avermectin toluene solution is heated to 79-81℃, and the deglucosation is performed by using hot water at 79-81℃ for washing at least 2 times, then water is added to the deglucosated avermectin toluene solution, and the toluene is removed by evaporation, to obtain a deglucosated avermectin product, i.e., an aqueous solution of the deglucosated avermectin.

[0021] Further, toluene is added to the avermectin paste at a volume ratio of 1:5-6.

[0022] When the avermectin toluene solution is washed, hot water at 79-81℃ is first added to the avermectin toluene solution heated to 79-81℃ at a volume ratio of 6:1-1.5, stirring is performed for 25-40 min, then the solution is allowed to stand and separate into layers, and the water layer is discharged.

[0023] Further, in step 5, the addition of the crystallization solvent for crystallization includes the following steps:

[0024] The crystallization solvent is added to the aqueous solution of the deglycosylated abamectin, and the temperature is increased to 70-77 DEG C while stirring until the abamectin is dissolved, and then the temperature is decreased to 25-30 DEG C, and the abamectin is crystallized after 2 hours of preservation, and the crystals are washed with the crystallization solvent to obtain the finished abamectin.

[0025] Further, the crystallization solvent is one or more of methanol, ethanol, acetone and acetonitrile.

[0026] The crystallization solvent is added to the aqueous solution of the deglycosylated abamectin at a weight-volume ratio of 1 kg:8-10 L.

[0027] Technical solution two:

[0028] An abamectin prepared by the extraction and purification method.

[0029] Compared with the prior art, the present application has the following advantages:

[0030] The present application has found that the oil and fat substances exist in the extraction solution of abamectin, and the amount of the oil and fat substances seriously affects the crystallization times of the abamectin. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in combination with the embodiments.

[0032] Embodiment 1

[0033] An abamectin, an extraction and purification method thereof, comprising the following steps:

[0034] Step 1, drying and crushing: the fermentation liquid is heated to 80-85 DEG C, and the solid-liquid separation is performed by plate and frame filter pressing to obtain the wet mycelium, and then the wet mycelium is dried by blowing air for 25 minutes, and the crushing is started, and the hot air at 90 DEG C is continuously blown to dry while crushing until the moisture content of the mycelium is less than or equal to 40%, and the mycelium is ready for use;

[0035] Step 2, leaching: the dried and crushed mycelium is leached with the organic solvent ethanol, and the leaching is performed for 3 times, and the mass ratio of the mycelium to ethanol is 1:110 each time, and the leaching time is 4 hours each time, and the extraction solution is collected;

[0036] Step 3, impurity removal: after the extract is filtered, the multi-effect evaporator is used to evaporate and concentrate to 50% of the original extract volume, and the oil and fat substances precipitated are removed by centrifugation with an explosion-proof disc centrifuge to obtain supernatant;

[0037] Step 4, evaporation and concentration: the supernatant is continuously evaporated and concentrated in an evaporation tank until the temperature in the evaporation tank is raised to 80-82℃ and the vacuum degree reaches -0.08 to -0.082 MPa, and an abamectin paste is obtained;

[0038] Step 5, desugarization: according to the volume ratio of abamectin paste to toluene 1:5.5, toluene is added to the abamectin paste, and after stirring and dissolving, the abamectin toluene solution is heated to 79-81℃, and then washed twice with hot water at 79-81℃ to remove sugar. Then water is added to the desugared abamectin toluene solution, and toluene is evaporated to replace water, to obtain a desugared abamectin product, i.e. an aqueous solution of desugared abamectin;

[0039] During the washing of the abamectin toluene solution, first, according to the volume ratio of abamectin toluene solution to water 6:1.5, 79-81℃ hot water is added to the abamectin toluene solution heated to 79-81℃, and stirred for 35 min, then separated and the water layer is discharged;

[0040] Step 6, crystallization:

[0041] According to the mass-volume ratio of abamectin to crystallization solvent 1g:9mL, crystallization solvent methanol is added to the aqueous solution of desugared abamectin, and the temperature is raised to 70-77℃ while stirring to dissolve the abamectin, then the temperature is lowered to 25-30℃, and the crystals are washed with methanol, then dried and crushed to obtain the finished product of abamectin;

[0042] The content of B1 in the abamectin product obtained in this example is 95.8%, and the yield of B1 is 96.3%.

[0043] Example 2

[0044] An abamectin and its extraction and purification method, comprising the following steps:

[0045] Step 1, drying and crushing: the fermentation broth is heated to 90℃, and solid-liquid separation is performed by plate and frame filter pressing to obtain wet mycelium. Then the wet mycelium is dried by blowing hot air for 30 min, and then crushing is started while the hot air at 80℃ is continued to blow to dry the mycelium, until the moisture content of the mycelium is ≤40%, ready for use;

[0046] Step 2, leaching: add organic solvent ethanol to the dried and crushed mycelium for leaching, the mass ratio of mycelium to ethanol is 1:120, leaching for 3 times, each time for 4 hours, collect the extract;

[0047] Step 3, impurity removal: filter the extract, evaporate and concentrate to 50% of the original extract volume using a multi-effect evaporator, then remove the precipitated oil substances by centrifugation using an explosion-proof disc centrifuge to obtain a supernatant;

[0048] Step 4, evaporation and concentration: continue to evaporate and concentrate the supernatant using an evaporation tank until the temperature in the evaporation tank reaches 80-82°C and the vacuum degree reaches -0.08 to -0.082 MPa, obtaining an abamectin paste;

[0049] Step 5, desugarization: add toluene to the abamectin paste at a volume ratio of 1:5, stir and dissolve, then heat the abamectin toluene solution to 79-81°C, and wash at least twice with hot water at 79-81°C to remove sugar, then add water to the desugared abamectin toluene solution, evaporate to remove toluene, and replace toluene with water to obtain a desugared abamectin product, i.e. a desugared abamectin aqueous solution;

[0050] During washing of the abamectin toluene solution, first add hot water at 79-81°C to the abamectin toluene solution at a volume ratio of 6:1, stir for 35 minutes, then separate the layers and discard the water layer;

[0051] Step 6, crystallization:

[0052] Add crystallization solvent methanol to the desugared abamectin aqueous solution at a mass-volume ratio of 1 kg:10 L, stir and heat to 70-77°C to dissolve the abamectin, then cool to precipitate crystals, when the temperature drops to 25-30°C, keep the temperature for 2 hours, filter, wash the crystals with crystallization solvent or ethanol, then dry and crush to obtain the finished abamectin product;

[0053] The content of B1 in the abamectin product obtained in this example is 95.9%, and the yield of B1 is 97.2%.

[0054] Example 3

[0055] An abamectin extraction and purification method, comprising the following steps:

[0056] Step 1, drying and crushing: the fermentation broth is heated to 80℃, and solid-liquid separation is performed by plate and frame filter pressing to obtain wet mycelium. Then the wet mycelium is dried by blowing for 20 min, and crushing is started. The hot air at 100℃ is continuously blown while crushing until the moisture content of the mycelium is ≤40%, for standby;

[0057] Step 2, leaching: the dried and crushed mycelium is added with organic solvent ethanol for leaching. The mass ratio of the mycelium to ethanol is 1:100 for each leaching. Each leaching time is 4 h. The extract is collected;

[0058] Step 3, impurity removal: after the extract is filtered, the multi-effect evaporator is used to evaporate and concentrate the extract to 50% of the original volume. Then the oil and fat substances precipitated are removed by centrifugation with an explosion-proof disc centrifuge to obtain supernatant;

[0059] Step 4, evaporation and concentration: the supernatant is continuously evaporated and concentrated by an evaporation tank until the temperature in the evaporation tank is raised to 80℃-82℃ and the vacuum degree reaches -0.08MPa to -0.082MPa to obtain an avermectin paste;

[0060] Step 5, desugaring: according to the volume ratio of the avermectin paste to toluene 1:5, toluene is added to the avermectin paste. After stirring and dissolving, the avermectin toluene solution is heated to 79℃-81℃. Then the solution is washed twice with hot water at 79℃-81℃ for desugaring. Then water is added to the desugared avermectin toluene solution. The toluene is evaporated and removed to realize the displacement of toluene and water to obtain the desugared avermectin product, i.e. the aqueous solution of desugared avermectin;

[0061] During the washing of the avermectin toluene solution, first, according to the volume ratio of the avermectin toluene solution to water 6:1, hot water at 79℃-81℃ is added to the heated avermectin toluene solution. After stirring for 35 min, the solution is allowed to stand and separate into layers. Then the water layer is discharged;

[0062] Step 6, crystallization:

[0063] According to the mass-volume ratio of avermectin to crystallization solvent 1kg:8L, the crystallization solvent methanol is added to the aqueous solution of desugared avermectin. While stirring, the temperature is raised to 70℃-77℃ to dissolve the avermectin. Then the temperature is lowered to 25℃-30℃ for 2 h. After filtration, the crystals are washed with methanol, and then dried and crushed to obtain the finished avermectin product;

[0064] The content of B1 in the finished avermectin product obtained in this example is 95.3%, and the yield of B1 is 98.5%.

[0065] Comparative Example 1

[0066] An avermectin and an extraction and purification method thereof, comprising the following steps:

[0067] Step 1, drying and crushing: the fermentation broth is heated to 85℃, and plate and frame filter pressing is performed to obtain wet mycelium. Then, the wet mycelium is blown dry for 25 min, and crushing is started. Hot air at 90℃ is continuously blown to dry the mycelium while crushing, until the moisture content of the mycelium is ≤40%, for standby use;

[0068] Step 2, leaching: the dried and crushed mycelium is leached with an organic solvent ethanol. The mass ratio of the mycelium to ethanol is 1:110 in each leaching. Each leaching is performed for 4 h. The leaching liquid is collected;

[0069] Step 3, evaporation and concentration: the leaching liquid is filtered, and then evaporated and concentrated by using an evaporation tank, until the temperature in the evaporation tank is raised to 80℃-82℃ and the vacuum degree reaches -0.08MPa to -0.082MPa, to obtain an avermectin paste;

[0070] Step 4, desugaring: tovermectin paste, toluene is added at a volume ratio of 1:5.5. After stirring and dissolving, the avermectin toluene solution is heated to 79℃-81℃. The solution is washed twice with hot water at 79℃-81℃ to remove sugar. Then, water is added to the desugared avermectin toluene solution, and toluene is evaporated to replace water, to obtain a desugared avermectin product, i.e., an aqueous solution of desugared avermectin;

[0071] In the washing of the avermectin toluene solution, hot water at 79℃-81℃ is first added to the avermectin toluene solution at a volume ratio of 6:1.5. After stirring for 35 min, the solution is allowed to stand and separate into layers, and the water layer is discharged;

[0072] Step 5, primary crystallization:

[0073] The aqueous solution of desugared avermectin is added with crystallization solvent methanol at a weight-volume ratio of 1kg:9L. The solution is stirred and heated to 70℃-77℃ to dissolve the avermectin. Then, the solution is cooled to precipitate crystals. When the temperature is lowered to 25℃-30℃, the solution is kept for 2 h, filtered, and the crystals are washed with methanol to obtain primary crystals;

[0074] Step 6, secondary crystallization:

[0075] The primary crystals are added with methanol at a mass-volume ratio of 1kg:7-8L. The solution is stirred and heated to 75℃-77℃ to dissolve the avermectin. Then, the solution is cooled to precipitate crystals. When the temperature is lowered to 25℃-30℃, the solution is kept for 2 h, filtered, and the crystals are washed with methanol to obtain secondary crystals;

[0076] Step 7, tertiary crystallization:

[0077] Step 6 was repeated for a third crystallization, and the wet crystals were then dried, pulverized to obtain the abamectin product.

[0078] The content of B1 in the abamectin product obtained in the present comparative example was 94.6%, and the yield of B1 was 95.0%.

[0079] The above-described embodiments are merely preferred embodiments of the present application and are not exhaustive of the possible implementations of the present application. Any obvious modifications made by those skilled in the art without departing from the principles and spirit of the present application should be considered to be within the scope of the claims of the present application.

Claims

1. A method for extracting and purifying avermectin, characterized by, It comprises the following steps: Step 1, leaching: adding organic solvent to the Streptomyces avermitilis mycelium for leaching, and collecting the extract; Step 2, impurity removal: after filtering the extract, evaporating and concentrating to 50% of the original extract volume, removing the oil and grease precipitate by centrifugation, and obtaining the supernatant; the centrifugation in step 2 uses an explosion-proof disc centrifuge; Step 3, evaporation and concentration: continuing to evaporate and concentrate the supernatant to obtain an avermectin paste; Step 4, desugaring: after desugaring the avermectin paste, obtaining the desugared avermectin product; Step 5, crystallization: adding a crystallization solvent to the desugared avermectin product for crystallization, and then separating the solid and liquid and washing the crystals to obtain the finished avermectin product.

2. The extraction and purification method of avermectin according to claim 1, wherein the preparation method of the Streptomyces avermitilis mycelium comprises the following steps: after solid-liquid separation of the Streptomyces avermitilis fermentation broth, the mycelium is blown dry for 20-30 min, then broken and dried by hot air until the moisture content of the mycelium is ≤40%, and the mycelium is ready for use.

3. The extraction and purification method of avermectin according to claim 1, wherein in step 1, the organic solvent is one or more of methanol, ethanol, acetone, and acetonitrile; and the mass ratio of material to liquid is 1:100-120 during leaching.

4. The extraction and purification method of avermectin according to claim 1, wherein in step 2, the evaporation and concentration uses multi-effect evaporation and concentration.

5. The extraction and purification method of avermectin according to claim 1, wherein in step 4, the desugaring uses toluene desugaring method.

6. The extraction and purification method of avermectin according to claim 5, wherein the desugaring treatment comprises the following steps: adding toluene to the avermectin paste, stirring and dissolving, then heating the avermectin toluene solution to 79-81°C, and washing at least twice with hot water at 79-81°C to remove sugar, then adding water to the desugared avermectin toluene solution, evaporating to remove toluene, and obtaining the desugared avermectin product, i.e. the aqueous solution of desugared avermectin.

7. The extraction and purification method of avermectin according to claim 6, wherein the volume ratio of the avermectin paste to toluene is 1:5-6, and toluene is added to the avermectin paste; when washing the avermectin toluene solution, first add hot water at 79-81°C to the heated avermectin toluene solution at a volume ratio of 6:1-1.5, stir for 25-40 min, then separate the layers, and discard the water layer.

8. The extraction and purification method of avermectin according to claim 1, wherein in step 5, the crystallization by adding a crystallization solvent comprises the following steps: ​ ​ ​ ​ ​ ​ ​ ​ ​ The crystallization solvent is added to the aqueous solution of the deglycosylated abamectin, and the temperature is increased to 70-77°C while stirring to dissolve the abamectin, and then the temperature is decreased to 25-30°C to crystallize, and the temperature is kept for 2 hours, and then the crystals are filtered and washed with the crystallization solvent to obtain the finished abamectin.

9. The method according to claim 6, characterized in that, the crystallization solvent is one or more of methanol, ethanol, acetone and acetonitrile; The crystallization solvent is added to the aqueous solution of the deglycosylated abamectin at a weight-volume ratio of 1 kg:8-10 L.