41 results about "Avermectin B1a" patented technology

The invention relates to a preparation method of an Abamectin B2a fine powder. The method comprises the following steps: A, concentrating an Abamectin B1a crystallization mother liquor into a paste state; B, dissolving the obtained paste with sec-butyl acetate, and then adding a tetrabutyl ammonium bromide aqueous solution for washing and layering; C, concentrating the sec-butyl acetate solution subjected to washing and layering, then adding a crystallization solvent for dissolution, naturally cooling to room temperature, crystallizing, and filtering to obtain an Abamectin B2a fine powder crude product; and D, recrystallizing the Abamectin B2a fine powder crude product to obtain the Abamectin B2a fine powder. According to the invention, waste Abamectin crystallization mother liquor is recovered and utilized to extract effective substances; tetrabutyl ammonium bromide aqueous solution is used for washing, which has better impurity removal effect than traditional water washing or saturated brine washing, and makes the solution layer more easily; aromatic hydrocarbon is used as the crystallization solvent; and the content of obtained B2a fine powder is higher than 93%.

The present invention relates to a crystallization method of abamectin B 1a. Said method includes the following steps: using crystallization solvent n-butanol to stir and dissolve primary crude powder of abamectin B 1a at 75-100deg.C to saturation, filtering while the saturated solution is hot to obtain clear hot-saturated solution; slowly cooling said solution to that when the supersaturation degree is 1-3, adding crystal seeds, constant stirring for 20-60min, its stirring speed is 120-300rpm, and cooling to make crystallization, fitering crystal slurry or centrifugally-separating said crystal slurry, washing crystal and drying so as to obtain the invented abamectin B 1a.

The invention relates to a preparation method of high-purity abamectin B2a, which comprises the following steps: concentrating an abamectin B1a crystal mother solution to no fraction under vacuum conditions, thereby obtaining an ointment thick material; adding an extractant, extracting to obtain an extract, washing the extract with a saturated saline solution 2-3 times, and removing the water phase to obtain an n-butyl acetate solution; cooling the obtained n-butyl acetate solution to crystallize, growing the grain, and carrying out vacuum filtration to obtain an abamectin B2a coarse crystal; and recrystallizing the abamectin B2a coarse crystal, carrying out vacuum filtration, and drying to obtain the high-purity abamectin B2a refined powder. The environment-friendly nontoxic solvent n-butyl acetate is used instead of the toxic solvent aromatic hydrocarbon to produce the abamectin B2a refined product, so the harm to the in-field personnel body is low in the production operation process, and the environmental pollution is small. By using the n-butyl acetate as the crystallizing solvent of the B2a, the purity of the abamectin B2a refined powder is higher than 95%.

The invention belongs to the technical field of microorganisms, and particularly relates to a method for preparing avermectin (Avermectins). The method comprises the following steps: cultivating a streptomyces avermitilis strain capable of generating avermectin and genetic improved bacteria thereof in a first stage of fluid nutrient medium, and then inoculating into a second stage of fluid nutrient medium as a seed solution; fermenting and cultivating after inoculating the seed solution into the second stage of fluid nutrient medium, and feeding a sodium propionate precursor to carry out feeding cultivation; collecting the avermectin B1a from fermentation broth after fermentation is finished. The effective method has the characteristics of being high in production efficiency and the like.

An abamectin microsoftgel for preventing and eliminating the pests of agricultural crops is prepared from the abamectin as core and wall material by interface polymerization method. Its advantages are low cost, slow release and low poison.

The invention relates to avermectin producing bacteria and a preparation method and application thereof. Specifically, aveD gene in wild type avermectin producing bacteria is inactivated to obtain a strain getting rid of an A component and only producing a B component; by anaplerosis of a homologous gene of the aveC gene (preferably meiC gene in a Meilingmycin biosynthetic gene cluster) on the basis of simultaneous inactivation the aveD gene and aveC gene, 95wt% above of the obtained mutant fermentation product is avermectin B2a. The product avermectin B2a can be used as a precursor for being directly used for large-scale synthesis of high purity avermectin B1a and ivermectin.

The invention relates to a method preparing abamectin Bla fine powder by secondary crystallization in abamectin Bla. The method comprises the steps of condensing an abamectin Bla crystallization mother liquid until no fraction is generated in a vacuum condition, so as to obtain a thick ointment slurry; adopting sec-Butyl acetate as an extraction agent, growing the grain to obtain a plurality of abamectin Blas when the temperature is risen to 90-95 DEG C and the stirring speed is 10-20 r/min, therefore the yield of the abamectin Bla in the abamectin Bla crystallization mother liquid can be improved.

The invention discloses a milbemycin oxime compound and a preparation method thereof. The compound as shown in a general formula (I) in the specification is prepared by the steps of carrying out hydrolysis reaction on avermectin B1a to remove C13-position glycosyl, oxidizing both C5-position hydroxyl and C13-position hydroxyl into keto through oxidation reaction, and finally converting the two kinds of keto into oximido, wherein the structure of the compound is confirmed by virtue of the mass spectrum and nuclear magnetic resonance analysis testing technology. According to the milbemycin oxime compound and the preparation method, the milbemycin oxime compound is prepared by starting materials which are cheap and easily obtained; the preparation method has the characteristics of mild reaction condition, simpleness in operation process, low cost and higher yield.

The invention discloses a method for extracting residual avermectin B1a from primary crystallization mother liquor of avermectin B1a. The method comprises the steps that low-grade ketone is added to avermectin factice, heating and stirring are conducted to make the low-grade ketone dissolved, cooling and centrifugation are conducted, obtained supernatant is recycled and concentrated, and second factice is obtained; crystallization solvent is added to the second factice which is dissolved through heating, cooling is conducted to enable crystals to grow, the crystals are separated, and coarse powder is obtained; methanol is added to the coarse powder, then activated carbon is added for decoloring treatment, filtrate is recrystallized twice, and avermectin B1a fine powder with the content of the avermectin B1a larger than or equal to 95% is obtained. By means of the method for extracting the residual avermectin B1a from the primary crystallization mother liquor of the avermectin B1a, the B1a component in the primary crystallization mother liquor can be effectively recycled, 86% of the B1a component in the mother liquor can be recycled through the primary crystallization, and the content of the B1a component in the obtained coarse powder reaches up to 65%. In addition, the method has the advantages of being simple in process, low in cost and suitable for the needs of industrial production and meets the industrial requirements, and meanwhile the realistic problem that the factice is banned from using nationally is solved.

The invention discloses a method for preparing high-purity Abamectin. The method comprises the following steps: dissolving Abamectin coarse powder in acetone, loading a sample to a chromatographic column filled with octadecyl silane bonded silica gel inversed phase chromatography fillers, gradient eluting the sample by using mixed liquid of a polar solvent and water as eluent, and carrying out stepwise collection, liquid phase detection, mixing, concentration and drying to obtain the target product, the purity of Abamectin B1 in the target product is 98.5-99.5%, and the purity of Abamectin B1a is not larger than 97% while not smaller than 95%. The component proportions of Abamectin B1a and Abamectin B1b in the final product of the invention are controllable, B1b is not larger than 5.0%, the other impurities 1# to 9# are not larger than 0.1%, the process is simple, the yield is stable, the quality is controllable and safer technical support is provided for production of pharmaceutical grade raw materials.

The invention relates to a method used for increasing industrial avermectin B<1a> yield via optimization of fermentation medium. It is found via large scale of screening that adding of an appropriate concentration of calcium chloride into streptomyces avermitilis fermentation medium is capable of increasing B<1a> yield obviously. The invention also provides a medium used for the method.

The invention relates to a novel Avermectin derivative and a preparation method thereof. The preparation method comprises the following steps: A, dissolving Avermectin B1a or Avermectin B2a into an organic solvent; B, cooling down the solution, adding a substitution reagent and dripping an acid-capturer; C, adding the reaction solution into a sulfuric acid solution, regulating pH, stilling, layering, extracting, adding an organic phase into an ammonia solution, regulating pH to be neutral, stilling, layering, extracting and merging the organic phase; D, performing distillation of the organic phase under reduced pressure to obtain the product. According to the invention, on the basis of the Avermectin B2a or B1a, C5-OH is subject to further chemical modification, and compared with the common Avermectin product, the novel Avermectin derivative has the advantages of high drug effect, broad insecticidal spectrum, good persistence, no residues, no pollution, high efficiency and no resistance. The novel Avermectin derivative has extremely high activity on many pests and mite, has the function of not only stomach toxicity but also killing and has a very good insecticide effect at a very low dosage.

The invention discloses an abamectin B1a fluorescence indicator, which is a compound shown in a formula A-1 or A-2 in the specification. The abamectin B1a fluorescence indicator can be used as a pesticide, an insect physiological indicator and an insect cell fluorescence tracer, and can also be used as an anticancer agent.

The invention relates to a synthetic method of an emamectin benzoate crude product, which is characterized in that: avermectin B1a is used as an initial raw material, and is subjected to an oxidationreaction, an ammoniation reaction, a reduction reaction and a salification reaction to obtain the emamectin benzoate crude product, and the reactions are carried out in a reaction system using dimethylformamide, tetrahydrofuran or tetrahydropyrane as a reaction solvent. According to the invention, the abamectin B1a is directly used as an initial synthesis raw material; the emamectin benzoate is synthesized by adopting a four-step method instead of a six-step method, so that the synthesis process steps are simplified, the production period is shortened, the production cost advantage is obvious,only one reaction solvent is used in the whole synthesis process, the recycling is convenient, the discharge amount of byproducts is very low, and the environmental pollution is not easily caused.

The invention discloses a quick analysis method for a reaction process of emamectin benzoate and relates to an analysis method for a chemical reaction intermediate process. By utilizing the method, the problems that the time for high performance liquid chromatograph is long, the operation steps are minute and complicated, the detection is time-consuming, a large number of samples need to be measured, the provided experimental data often lags behind the production process, the monitoring of the production process is incomplete and problems can not be found in time are solved. The method comprises the following steps: 1) establishing a sample library; 2) establishing a sample spectral pattern library; 3) selecting a sample; 4) carrying out pretreatment on the sample; 5) establishing a standard sample model; 6) establishing a quantitative analysis model, and getting an optimal quantitative analysis model; and 7) collecting spectral information of the sample to be tested, and predicting the contents of residual avermectin B1a and double-protection matter in the sample to be tested through the optimal quantitative analysis model. The analysis of the sample can be completed within 1 minute by the method, thus the method is time-saving, labor-saving and cost-saving and is easy for operation.

The invention relates to a method for determining abamectin in soil, which comprises the following steps: adding a soil sample into acetone for treatment, and extracting a sample solution to be detected; preparing an abamectin standard solution by using acetonitrile as a solvent; respectively detecting and analyzing the sample solution to be detected and the abamectin standard solution by adoptinga high performance liquid chromatography; and carrying out qualitative and quantitative analysis on the abamectin B1a and the abamectin B1b in the soil sample according to the detection and analysisresults. The method for determining abamectin in soil provided by the invention has the advantages of simple and convenient detection process, high sensitivity and low detection limit, which can realize the rapid detection of the abamectin content in an actual soil sample, and has good application prospect.

The invention relates to an extracting method for abamectin B1a. The extracting method is characterized by comprising the following process steps: first, filtering abamectin fermenting liquid by adopting a micro-filtration membrane to obtain abamectin-rich membrane paste; then, extracting the membrane past by using a compound solvent; next, adsorbing by using an aluminium oxide chromatographic column and desorbing by butyl alcohol after the obtained extracting liquid is concentrated; collecting desorbing liquid of a B1 stage, de-colouring, filtering and performing primary crystallizing to obtain abamectin B1 crude product; re-crystallizing through ethyl acetate to obtain a finished product with high content of the abamectin B1a. According to the extracting method, the abamectin is extracted in the mode of adopting micro-filtration membrane and compound solvent extracting and combining an aluminium oxide chromatographic column and butyl alcohol desorbing process, so that the abamectin and the product quality can be effectively improved; moreover, the process is simple; the solvent loss is little; the solvent is easy to recycle; the safety is high; meanwhile, environmental pollution can be reduced.

The invention provides a method for improving the yield of avermectin and a producing strain. The method is to construct an overexpressed genetically engineered strain of a gene mce (SAV2857) encodedby a methylmalonyl-CoA epimerase in streptomyces avermitilis. The genetically engineered bacterium obtained by the invention can be directly used for the fermentation production of the avermectin; thefermentation unit of the avermectin is improved, the yield of avermectin B1a is increased by about 25% compared with that of an original strain, and the production cost is lowered; and the genetically engineered bacterium has important industrial application prospects.