37 results about "Nemadectin" patented technology

The invention provides a purification method for Nemadectin. The method comprises the following steps: performing filter pressing on flocculated Nemadectin-containing fermentation liquid to obtain filter press bacteria dregs; extracting the filter press bacteria dregs by using the aqueous solution of a first solvent to obtain a Nemadectin-containing extract; stripping the extract by using a second solvent to obtain a Nemadectin-containing stripping liquid, wherein the polarity of the second organic solvent is weaker than that of the first organic solvent; concentrating the stripping extract and crystallizing to obtain the purified Nemadectin. According to the purification method for the Nemadectin, all of the adopted separation and purification means are conventional separation means in bio-pharmacy; equipment has high universality and low cost; moreover, the production operation is simple and convenient, the production operating cost is low, and the enlargement of production scale is facilitated.

The invention discloses a method for preparing high-purity nemadectin and belongs to the field of medicinal chemistry. The nemadectin is a sixteen-member macrolide type anthelmintic antibiotic and mainly used for synthesizing moxidectin with the better anthelmintic effect. According to the method for preparing the high-purity nemadectin, the nemadectin is extracted through an ethanol-water solution, and an extract is obtained, decolorized through ion exchange resin, deproteinized and desugared through macroporous adsorption resin and finally adsorbed and separated through the appropriate macroporous adsorption resin, so that nemadectin products with the purity higher than 90% can be prepared. The method is high in pertinency through matched usage of the resin, and the prepared high-purity nemadectin has great significance in synthesis of the high-purity moxidectin.

The invention relates to a method for preparation of moxidectin. The method includes subjecting Nemadectin to protective reaction, oxidation reaction, oximation reaction and deprotection reaction in order, thus obtaining moxidectin. Specifically, the protective agent employed in the protective reaction is tert-butyl dimethylchlorosilane, and after the oximation reaction, the solid form crude product obtained by the oximation reaction is subjected to crystallization, and then the deprotection reaction is carried out on the obtained crystal. The method provided by the invention increases the product content, further reduces the difficulty for follow-up utilization of macroporous resin for purification, and improves the column loading amount, reduces the number of column chromatography, maintains or even improves the purity of the final product, and lowers the production cost.

The invention relates to a method of chemically synthesizing moxidectin and belongs to the field of medicinal chemistry. The method comprises the following step: carrying out a reaction on nemadectin as a raw material and 4-chlorophenoxyacetyl chloride as an upper protective agent, and preparing moxidectin through a reaction of four steps: upper protection, oxidization, oximation and deprotection, wherein the reaction sequence of oximation and deprotection can be interchanged without affecting the final reaction product. In the reaction process, the products in upper protection, oxidization and oximation can be recrystallized and extracted through methanol and the like, so that the requirements on the purity of the raw material is reduced, the operating flow is simplified and the reaction cost is lowered.

The invention provides a nemadectin purification method. The method comprises the steps that: (1) a nemadectin crude product is provided; (2) the nemadectin crude product is mixed with liquid-state organic salt, and filtering is carried out, such that a filtrate is obtained; (3) the obtained filtrate is mixed with C5-C20 alkane, such that washing is carried out; and separation is carried out, such that a liquid-state organic salt-phase solution is obtained; and (4) the liquid-state organic salt-phase solution obtained in the step (3) is subjected to cooling crystallization, such that nemadectin is obtained. Compared with prior arts, the method has the following advantages: defects of current methods such as resin absorption separation are overcome; the purity of obtained nemadectin is high; the method is simple and feasible; energy consumption is low; cost is low; and single processing capacity is high. The method is suitable for industrialized mass productions.

The invention discloses a method for separating and preparing a high-purity Moxidectin membrane, and belongs to the technical field of pharmaceutical chemistry. The method comprises the following steps: performing membrane filtration on a pre-purified Nemadectin solution; after extraction with dichloromethane, removing solvents by using conventional concentration; successively performing a protection feeding reaction, an oxidation reaction, an oximation reaction and a protection removing reaction on concentrate to obtain a Moxidectin crude solution; filtering to remove impurities through a membrane separation technique; obtaining a high-purity Moxidectin concentrated solution through a membrane concentration technique. The method disclosed by the invention uses the membrane separation technique to replace column chromatography and a macroporous resin adsorption and separation method, the technique is stable, controllable, simple and practical, the industrialization is easy, the dosage of the solvents is reduced, and a high-temperature solvent removing process of a material solution is omitted, so that the degradation risk of products is reduced, the product purity, the product quality and the product yield are improved, at the same time, the energy resources are saved, and the production cost is reduced.

The invention discloses a method for chemical synthesis and purification of moxidectin, and relates to the technical field of synthetic medicines. The method comprises the following steps: (1) carrying out upper protective reaction on nemadectin to obtain an upper protective crude product; (2) carrying out oxidation reaction on the upper protective crude product to obtain an oxidized crude product; (3) carrying out chromatography purification of macroporous resin on the oxidized crude product, and concentrating to obtain an oxidized pure product; (4) carrying out deprotection reaction on the oxidized pure product to obtain a deprotected product; and (5) carrying out oximation reaction on the deprotected product, carrying out chromatography purification of macroporous resin, concentrating, filtering and drying in vacuum to obtain the moxidectin of which the purity is higher than 96% and the maximal single impurity content is lower than 0.3%. The upper protective crude product is subjected to chromatography purification of the macroporous resin after oxidized reaction; and the impurities introduced into the subsequent chemical reaction are reduced, so that the purity of the moxidectin is improved; the impurity content is reduced; the total yield of the moxidectin is improved; and the cost is reduced.

The invention provides a method of purifying nemadectin through crystallization. The method includes: taking a nemadectin crude product, adding a first nonpolar solvent, and heating for dissolving to obtain a nemadectin solution; adding a second nonpolar solvent to be turbid, and performing gradient cooling for crystallization; sequentially filtering and drying to obtain a nemadectin pure product. By using the method, the problem that the nemadectin crude product is difficult to crystallize is solved, and high-purity nemadectin crystals are obtained. The method is simple to operate, simple in equipment, low in cost, environment-friendly and convenient for industrial production.

The invention discloses a method for detecting nemadectin content based on a liquid chromatography external standard method and specifically relates to the detection for the nemadectin content. The method provided by the invention comprises the following steps: precisely weighting a nemadectin sample and a nemadectin reference substance in same weight and placing into two volumetric flasks, respectively adding 95% ethyl alcohol solution and fixing the volume to a same scale, uniformly mixing and preparing into a sample solution and a reference solution, and then quantitatively and precisely weighting the sample solution and the reference solution acquired in the step a in same volume and performing high performance liquid chromatography determination, wherein the chromatographic conditions are as follows: octadecyl silane bonded silica gel column selected as a chromatographic column, column temperature at 25-35 DEG C, 85% methyl alcohol as flowing phase, flow rate at 1.0-1.5mL/min, detection wavelength of 240nm and sampling volume at 20uL. According to the invention, the nemadectin content can be accurately detected, the accuracy is high, the repeatability is high, the linear relation coefficient can reach up to 0.99, the accuracy RSD is less than or equal to 2.0%, the sensitivity is high and the result is satisfying.

The invention provides a separation and purification method of high-purity moxidectin. The method includes the steps: performing solid-liquid separation on fermented liquid generated by streptomycin in a fermented manner; performing leaching to obtain nemadectin concentrated solution; performing upper protection, oxidation, deprotection and amination reaction on the nemadectin concentrated solution to obtain moxidectin methanol solution (MX-4); performing preparative HPLC (high-performance liquid chromatography) on the moxidectin methanol solution, performing concentration, extracting and layering, crystal, suction filtration and drying to obtain moxidectin finished products with the purity of 98%. The method is high in separation purity and product yield, low in solvent consumption, lessin operation step and suitable for commercial mass production.

In the present invention, a recombination of gene groups of nemadectin aglycon biosynthesis is performed for obtaining C-13 hydroxylnemadectin, to which sugar groups can be attached, and a production strain which produces C-13 hydroxylnemadectin is produced. Further, C-13 glycosylnemadectin producing strain is prepared by introducing aveBI-BVIII genes involving glycosidation of avermectin and biosynthesis of oleandrose. As described, C-13 hydroxylnemadectin and C-13 glycosidated nemadectin can be obtained effectively by using the producing strain prepared by means of the molecular genetic technology, and improvement in the biological activity thereof can be expected.

The invention discloses a method for preparing high-content nemadectin and belongs to the technical field of organic chemistry. According to the method, crystallized and purified 5-O (protecting group)-23-Oxo nemadectin or 5-O (protecting group)-23-formaldoxime nemadectin is taken as the raw material, and the high-content nemadectin is obtained through deoximation, reduction, deprotection and silicagel column separation; the HPLC purity of the obtained nemadectin is larger than or equal to 95.0A%, and content is larger than or equal to 93.0wt.%. The method has the advantages that aftertreatment is easy, column separation frequency is low, and nemadectin content is high.

The invention discloses a method for preparing moxidectin. The method sequentially comprises the following steps: with nemadectin is used as a raw material performing substitution, oxidization and de-protection reactions on allyl chlorocarbonate; The invention discloses a novel synthesis route, wherein used raw materials have characteristics of wide and sufficient source; the method has advantagesof proper cost, simple process, mild reaction conditions of each step, conventional operation, and production cost reducing.

The invention discloses a method for preparing high-purity 5-oxy(p-nitrobenzoyl)-nemadectin. According to the invention, nemadectin is adopted as a reaction initial raw material, and p-nitrobenzoyl chloride is adopted as an -OH protecting reagent, such that a 5-oxy(p-nitrobenzoyl)-nemadectin crude product is prepared; the 5-oxy(p-nitrobenzoyl)-nemadectin crude product is adopted as a raw material and is mixed with a solvent, such that a solution is prepared; an eluting agent is added, and cooling crystallization is carried out, such that 5-oxy(p-nitrobenzoyl)-nemadectin with higher purity is obtained. The method provided by the invention has the advantages of short crystallization time, low cost, high product purity and high yield. With the method, a basis is provided for the preparation of high-purity moxidectin.

The invention discloses a recombinant vector and recombinant bacteria for improving the yield of macrolide antibiotics and application, and belongs to the field of gene engineering. The purpose of the invention is to improve the yield and titer of macrolide antibiotics. A starting vector of the recombinant vector for efflux of macrolide antibiotics is pSET152T, a streptomyces bingchengensis BC-101-4 genome is used as a template to amplify a promoter and an efflux gene, and a sequence obtained by connecting the promoter and the efflux gene is integrated into the starting vector to obtain the recombinant vector. The promoter is located at the upstream of the efflux gene. Recombinant bacteria are constructed through genetic engineering transformation, in fermentation production, the feedback inhibition effect of a final product is relieved, and the yield of milbemycins, abamectin and nemadectin is increased.

The invention discloses a binary product fermentation method and two kinds of fermentation products thereof. The fermentation method for a composition containing Nemadectin comprises the steps of culture activation, cultivation enlarging, fermental cultivation and organic solvent purification, and recrystallization, chromatography and other complex steps are not needed. The invention further provides a composition and a pesticide preparation prepared through the fermentation method and the plant disease and pest preventing application.