12 results about "Epimer" patented technology

The invention relates to a high-selectivity synthesis method of an imidazo thiazolone compound based on epimer dissolution behavior regulation and control. The synthesis method comprises the following steps: taking a compound 1 and a compound 5 as reaction raw materials, and reacting in an organic solvent in the presence of a catalyst to obtain a compound 2; the compound 1 contains 8%-60% by mass of a compound 1b isomer and 40%-92% by mass of a compound 1a isomer. By controlling the specific content of the 1a isomer and the 1b isomer in the raw material of the compound 1, especially enough 1b isomer, the high yield and high selectivity of the target product 2 can be realized when the compound 1 is used for preparing the compound 2, and the content of the dehydration byproduct 4 is obviously reduced.

The present invention relates to a process for the industrial scale preparation of (3β,24S)-25,25,25-trifluoro-3-methyl-26,27-dinorergost-5-ene-3,24-diol, useful in counteracting the progression of highly disabling neurological diseases such as Alzheimer's, Parkinson's, and Huntington's disease, and having the structure shown below: The invention also relates to an improved method for the separation of two epimers that are obtained during the synthesis.

The present invention relates to a process for the industrial scale preparation of (3β,24S)-25,25,25-trifluoro-3-methyl-26,27-dinorergost-5-ene-3,24-diol, useful in counteracting the progression of highly disabling neurological diseases such as Alzheimer's, Parkinson's, and Huntington's disease, and having the structure shown below:The invention also relates to an improved method for the separation of two epimers that are obtained during the synthesis.

An N-formamidopyrazoline derivative is a compound having General Formula (I) or an enantiomer, a diastereomer, an epimer and a racemate thereof, or a pharmaceutically acceptable salt thereof. The compound is an antagonist of a ligand-gated non-selective cation channel receptor subtype P2X3, and can be used for treating or preventing various diseases mediated by the receptor P2X3.

The present application belongs to the technical field of enzyme preparation, and particularly relates to a high-stability allulose-3-epimerase fermentation preparation method. In the logarithmic growth phase of the recombinant bacteria fermentation, arginine and glutamic acid composition is supplemented to the basic medium, and a manganese ion-containing ethylenediamine bis-o-hydroxyphenylacetic acid complex is coupled and added. The above composition is added in the form of gelatin and sodium alginate cross-linked polymer slow-release microcapsules, and the complex is added in stages with interval. After the supplement, the stirring speed and the air-pure oxygen mixed gas composition are jointly adjusted to maintain a specific dissolved oxygen level to the fermentation endpoint. Through the amino acid intervention of the new peptide chain folding microenvironment, the generation of inclusion bodies is inhibited, and the chelated manganese ion acts as a cofactor precursor to bind to the enzyme protein active center in situ in the cell, thereby improving the soluble enzyme expression proportion and the cofactor loading rate. The problem of insufficient enzyme preparation thermal stability caused by protein misfolding and low intracellular cofactor loading rate in the conventional fermentation process is solved.

The invention discloses a preparation method of a paclitaxel EP impurity M. The preparation method comprises the following steps: dissolving a compound I paclitaxel in an organic solvent, adding strong lewis acid, and reacting at 20-25 DEG C to obtain a compound II paclitaxel EP impurity M. The paclitaxel EP impurity M is synthesized through a one-step method, the synthesis process is reasonable in design and high in operability, and the purity of the prepared paclitaxel EP impurity M reaches up to 98% or above.

The present disclosure relates to engineered bacterial glycoside-3-oxidases with improved catalytic and stability properties (and homologues) and their use in producing rare C3-sugar epimers. The present disclosure further relates to a method for the enzymatic oxidation of the C3-position of chemically protected saccharides at the C1-position, followed by a chemical reduction and deprotection steps.

The invention relates to the technical field of pharmaceutical analysis, in particular to a method for detecting the purity of omagazines tosylate for injection. The method mainly solves the technical problem that main components and key impurities such as epimers of the main components are difficult to effectively separate in existing chromatographic analysis. Optimized reversed-phase high performance liquid chromatography conditions are established, a phosphate buffer solution-acetonitrile gradient elution system with a specific pH value is adopted, precise weighing, system applicability verification and an automatic integration technology are combined, baseline separation of main components and impurities is achieved, and finally the content of the main components is accurately calculated through an area normalization method. The method has the advantages of good separation effect, strong specificity, high analysis efficiency and accurate and reliable result, and provides reliable technical guarantee for product quality control.

Provided in the present invention is a method for preparing mirogabalin besilate. The method comprises: reacting mirogabalin containing an epimer with benzenesulfonic acid in the presence of MTBE and an organic weak acid to precipitate a mirogabalin besilate solid. By means of performing salt formation in a specific reaction solvent, mirogabalin besilate with a high optical purity can be obtained, the separation of the epimer of the intermediate thereof by means of using a chiral organic amine or a chiral column is avoided, and the production cost is reduced. The method has the advantages of simple operation, a high yield and mild reaction conditions, is suitable for industrial production, and has good application prospects.

This invention discloses an omalicycline tosylate formulation and its preparation method, comprising the following steps: taking crude omalicycline tosylate solution, adding modified polylactic acid porous microspheres to it, and stirring and adsorbing under light-protected and nitrogen-protected conditions; after adsorption is completed, centrifuging separation, sampling and testing of the supernatant, and after the content of 4-β epimer meets the standard, freeze-drying the supernatant to obtain the omalicycline tosylate formulation; the modified polylactic acid porous microspheres are obtained by modifying polylactic acid porous microspheres with L-proline. This invention utilizes the interaction between modified polylactic acid porous microspheres and 4-β epimers to amplify the difference between 4-β epimers and the main product, achieving selective adsorption of 4-β epimers, enhancing separation efficiency, reducing 4-β epimer impurities in the product to a lower level, and maintaining good stability after reconstitution.

The invention discloses a specific quantitative detection method for 2-epimer and alpha-isomer in dapagliflozin, which adopts high performance liquid chromatography and uses a chiral chromatographic column as a separation unit. A filling agent of the chiral chromatographic column is [N-(R)-(+)-1-(1-naphthyl) ethyl] methacrylamide bonded silica gel; the mobile phase is obtained by compounding a disodium hydrogen phosphate solution and acetonitrile; the dapagliflozin 2-epimer and the dapagliflozin alpha-isomer are quantitatively determined by isocratic elution, the flow velocity of a mobile phase is 0.5-1.5 ml / min, the column temperature is 20-40 DEG C, efficient separation and quantitative detection of the dapagliflozin 2-epimer and the dapagliflozin alpha-isomer can be realized, the separation degree is greater than 1.5, quantitative detection of the 2-epimer can be carried out, and the method is suitable for industrial production. And the method has good sensitivity, specificity, precision, linearity, accuracy, solution stability and durability.

The invention provides a preparation method of 8-bit epimeric lubiprostone, which comprises the following steps: by taking a lubiprostone intermediate compound (II) as an initial raw material, carrying out six-step reaction of sulfonylation, elimination, hydroboration oxidation, oxidation, deprotection and saponification to prepare the 8-bit epimeric lubiprostone compound shown as a formula (I). The 8-bit epimeric lubiprostone provided by the invention is high in optical purity and good in stability. The lubiprostone API impurity is used as an impurity reference substance to be applied to lubiprostone API quality analysis, and the limit of the lubiprostone API impurity is controlled, so that the quality of the lubiprostone API can be improved.