37 results about "Nemadectin" patented technology

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. The method comprises the following steps: taking crystallized and purified 5-oxygen (protecting group)-23-oxo nemadectin as a raw material, and then reducing, de-protecting and separating with a silica gel column, thereby acquiring the high-content nemadectin. The HPLC purity of the acquired nemadectin is more than or equal to 95.0A% and the content is more than or equal to 93.0wt%. The method has the advantages of simple post-processing, few column separation times and high content of nemadectin.

The invention relates to a culture medium for producing nema rhzomorph by streptomyces fermentation and a cultivation method. The fermentation unit of the nema rhzomorph can be improved, the fermentation cycle can be shortened, the fermentation cost can be reduced, the effect on primary and auxiliary materials caused by the environment is reduced to the maximal extent, and adequate supply of the primary and auxiliary materials is ensured by using the culture medium formula and the fermentation control process provided by the invention, thereby achieving stable and efficient production of the nema rhzomorph.

The invention provides an optimal control method of a nemadectin fermentation impurity. The nimoktin fermentation impurity is of a structure before the moxidectin A impurity synthesis. The method comprises the operation steps of: controlling the age of seeds in a seed tank between 60 hours and 70 hours; reversely mounting bottom parabolic blades of the stirrer in a fermenting tank; and / or in the fermentation process, reducing the rotating speed of the stirrer in the fermenting tank after fermenting for 140 hours. The optimal control method of the nemadectin A1 fermentation impurity, which is provided by the invention, has the beneficial effects that the seed age control of the seed tank is refined and the control of the A1 impurity in the early stage after better viable seeds enter the fermenting tank is benefited; and through repeated observation and comparison, an optimized stirring pattern of the fermenting tank is screened out, the optimized stirring shearing force is small, the mixing is better, observed hyphae are more viable and the A1 impurity control in the early stage, of the fermenting tank, is benefited.

The invention provides a method for separating and purifying nemadectin by using the HPLC (high performance liquid chromatography). The method is implemented by taking styrene-divinylbenzene crosslinked microspheres as chromatographic packing through the steps that after a nemadectin coarse product solution is loaded in a chromatographic column, nemadectin adsorbed on the packing is eluted by using an acidic alcohol aqueous solution as a mobile phase. The method disclosed by the invention not only can achieve the high-purity and high-recovery-rate separation and purification of nemadectin, but also is small in mobile phase application amount, short in purification time and less in process step, so that the production cycle is greatly shortened.

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 producing Nemadectin through fermenting. In the Nemadectin production process through fermenting, carbohydrates are intermittently or continuously added to a fermentation liquid to maintain the total sugar concentration of the fermentation liquid at 10-40g / L in order to carry out fermenting production when the total sugar concentration of the fermentation liquid is less than 30g / L. The method enables the Nemadectin fermentation unit to be improved by above 50%, simultaneously has the advantages of simple production operation, low equipment requirements and low cost, and is a technology suitable for the industrialized production.