26 results about "Alanine methyl ester" patented technology

The invention relates to the technical field of enzyme engineering, in particular to an aminopeptidase mutant, a preparation method of the aminopeptidase mutant and application of the aminopeptidase mutant to preparation of L-carnosine. The aminopeptidase mutant is obtained by mutating wild type aminopeptidase and can be used for preparing the L-carnosine through reverse hydrolysis of beta-alanine methyl ester and L-histidine. The L-carnosine produced by using the aminopeptidase mutant disclosed by the invention has the following advantages: 1, the conversion rate is greater than or equal to 95%, the conversion time is short, and relatively cheap alanine methyl ester can be used as a raw material to catalytically prepare the L-carnosine; 2, the production process is simple, the reaction conditions are mild, and the green chemistry concept is met;

The invention discloses aminopeptidase for synthesizing L-carnosine and an application of the aminopeptidase. The amino acid sequence of the aminopeptidase is as shown in SEQ ID NO: 3 or 5. The aminopeptidase disclosed by the invention can catalyze L-histidine with high selectivity to synthesize L-carnosine in the presence of beta-alanine methyl ester, and has relatively high enzyme activity and industrial application value.

The application discloses a kind of water and fertilizer conditioning agent suitable for lime soil wheat-corn rotation system, belong to water and fertilizer conditioning agent preparation technical field.The water and fertilizer conditioning agent suitable for lime soil wheat-corn rotation system, by following weight parts component consists of:1.6-1.7 parts polyacrylamide, 16-17 parts zeolite, 16-17 parts humic acid, 49-51 parts attapulgite powder, 16-17 parts modified cellulose, 2.1-3.3 parts chitosan oligosaccharide derivative, wherein, modified cellulose is prepared by 4-vinyl benzoic acid, L-phenylalanine methyl ester hydrochloride, cellulose and 2-[dodecylthio (thiocarbonyl) thio]-2-methylpropionic acid as main raw material, synergist is prepared by dodecanol, tetrabutylammonium bromide, epichlorohydrin and 3-chloro-2-hydroxypropyl sulfonate sodium as main raw material.Water and fertilizer conditioning agent prepared by the method can effectively improve the yield of wheat and corn.

The invention relates to the field of enzyme engineering, and discloses an aminopeptidase mutant as well as a coding gene, a recombinant vector, a recombinant strain and application thereof, and the aminopeptidase mutant is obtained by performing mutation of at least one of S88L, Y150C and Q268F on an enzyme with an amino acid sequence as shown in SEQ ID NO: 1. The aminopeptidase mutant disclosed by the invention can catalyze L-histidine to synthesize L-carnosine in a high-selectivity manner in the presence of beta-alanine methyl ester, and the aminopeptidase mutant has relatively high L-carnosine yield and relatively low impurity content, and has industrial application value.

The application provides a synthesis method of L-selenium-methyl selenocysteine, which comprises the following steps: mixing dimethyl diselenide with sodium borohydride, then adding a sodium hydroxide solution to react, to obtain a sodium methyl selenide solution; preparing 3-chloro-L-alanine methyl ester hydrochloride, stirring the prepared 3-chloro-L-alanine methyl ester hydrochloride with the sodium methyl selenide solution to react; acidifying the solution after the stirring reaction, then extracting, removing impurities, heating the water phase, and reducing pressure distillation to obtain solid crystals; using methanol to extract the solid crystals twice, then adding triethylamine to stir and crystallize, to obtain L-selenium-methyl selenocysteine solid crude product; hydrating the L-selenium-methyl selenocysteine solid crude product, then recrystallizing to obtain L-selenium-methyl selenocysteine solid; the L-selenium-methyl selenocysteine synthesized by the application has the advantages of simple process route, mild conditions, high purity and high yield.

The invention relates to the technical field of medicinal chemistry, in particular to a method for preparing a fiazonepan intermediate. The method comprises the following steps: (1) carrying out methyl esterification reaction on D-alanine serving as a reaction substrate and a methyl esterification reagent to prepare D-alanine methyl ester; (2) carrying out Boc protection on an amino group of the D-alanine methyl ester by adopting a Boc reagent, so as to obtain N-Boc-D-alanine methyl ester; (3) carrying out an amide exchange reaction on the N-Boc-D-alanine methyl ester and ethanolamine to obtain an ethanolamine derivative IV; and (4) the ethanolamine derivative IV and tetrahydrofuran are subjected to a Mitsunobu reaction for ring closing, and the final product (R)-1-(t-butyloxycarboryl)-2-methyl piperazine-3-ketone is obtained. The method has the advantages of low cost, simplicity in operation, short reaction time and high yield.

The invention discloses a synthetic method of (S)-2-(N-t-butyloxycarboryl)-3-(4-bromine-2-thiazolyl) methyl propionate, which is characterized in that (R)-N-t-butyloxycarbonyl-3-iodo-alanine methyl ester and 2, 4-dibromothiazole are used as reactants, a reducing agent, a catalyst and a cocatalyst are added into a reaction solvent, and the (S)-2-(N-t-butyloxycarboryl)-3-(4-bromine-2-thiazolyl) methyl propionate is synthesized through one-step reaction. According to the invention, cheap reagents are adopted, the reaction can be completed in one step, the defects of use of an expensive noble metal catalyst, harsh reaction conditions and complex operation in the existing synthesis method are overcome, the yield is higher, and the method can be suitable for industrial production and has good economic value.

The invention provides an anti-aging heat-conducting polyurethane adhesive and a preparation method thereof, and belongs to the technical field of adhesives, and the preparation method comprises the following steps: homogenizing pretreated nano aluminum oxide copper and silane in water, then adding beta-alanine methyl ester hydrochloride and p-hydroxybenzamide, homogenizing to obtain a suspension, and drying to obtain the anti-aging heat-conducting polyurethane adhesive. Sequentially adding polyacrylic acid and the suspension into water, heating, stirring, cooling, centrifuging and drying to obtain modified nano aluminum oxide copper, and then adding the modified nano aluminum oxide copper into a waterborne polyurethane emulsion for stirring to obtain a mixed emulsion; ethyl p-hydroxyphenylacetate is added into 4-toluene hydroamine resin and water for homogenization, then the mixed emulsion is added for heating and stirring, and modified emulsion is obtained; and pouring the modified emulsion into a mold, and curing to obtain the anti-aging heat-conducting polyurethane adhesive. According to the technical scheme provided by the invention, excellent aging resistance and heat-conducting property can be realized without adding a large amount of high-performance filler.

The present application discloses a protease having carnosine hydrolase function and its use in L-carnosine synthesis, wherein the protease comprises the amino acid sequence shown in SEQ ID NO: 6. The protease described herein can utilize either β-alanine methyl ester hydrochloride and L-histidine as substrates, or β-alanine and L-histidine as substrates, thereby reducing costs and utilizing β-alanine produced due to the instability of β-alanine methyl ester hydrochloride.

The invention discloses a synthesis method and application of (3S)-1, 3-dimethyl piperazine-2-ketone, and the method comprises the following steps: S101, dissolving D-alanine methyl ester hydrochloride in a first organic solvent, then adding alkali A and 2-methylaminoethanol, after addition, heating to 60-150 DEG C, carrying out stirring reaction for 8-20 hours, after the reaction is completed, carrying out first post-treatment on the reaction liquid, and carrying out second post-treatment on the reaction liquid, so as to obtain the (3S)-1, 3-dimethyl piperazine-2-ketone; the crude product of (R)-2-amino-N-(2-hydroxyethyl)-N-methyl propionamide is obtained; and S102, dissolving (R)-2-amino-N-(2-hydroxyethyl)-N-methylpropanamide in a second organic solvent, then adding (1, 2-bis (ethoxycarbonyl) hydrazino) triphenylphosphonium trifluoromethanesulfonate and alkali B, after addition, carrying out stirring reaction at 15-40 DEG C for 8-20 hours, and after the reaction is completed, carrying out secondary post-treatment on the reaction liquid to obtain the target (3S)-1, 3-dimethyl piperazine-2-ketone.

The invention discloses an aminopeptidase for synthesizing L-carnosine and an application thereof. The amino acid sequence of the aminopeptidase is shown in SEQ ID NO: 3 or 5. The aminopeptidase of the invention can catalyze L-histidine to synthesize L-carnosine with high selectivity in the presence of β-alanine methyl ester, has high enzyme activity, and has the value of industrial application.

The invention relates to the technical field of drug detection, and particularly discloses a method for detecting related substances in cycloserine. The specific derivatization reagent is adopted, so that the impurities and the benzaldehyde derivative are subjected to derivatization reaction to generate amide, and the ultraviolet absorption response intensity of the impurities is improved; according to the method, a ZORBAX SB-Phenyl chromatographic column is adopted to carry out HPLC (High Performance Liquid Chromatography) analysis on a cycloserine sample, so that rapid and accurate detection on impurities such as D-serine, D-serine methyl ester hydrochloride, 3-chloro-D-alanine methyl ester hydrochloride and L-cycloserine in the cycloserine at the same time is realized. The detection method is high in specificity, low in detection limit and quantitation limit, good in linear relation, high in recovery rate, good in repeatability, high in stability, good in durability, easy and rapid to operate, low in detection cost and accurate and reliable in detection result, can be used for quality control and comprehensive evaluation of cycloserine, and provides reliable guarantee for improving and controlling the quality of cycloserine.

The present invention discloses a preparation method of methyl carteolol, a therapeutic drug for ulcerative colitis: Step 1, 5-(dimethylamino)-2-(methylamino)benzoic acid reacts with Nα-Boc-4-amino-L-phenylalanine methyl ester to first obtain an intermediate compound, and then the boc group is removed to obtain the intermediate 4-(6-dimethylamino-1-methylquinazoline-2,4[1H,3H]-dione-3-yl)-L-phenylalanine methyl ester; Step 2, the product of Step 1 and 2,6-dichlorobenzoic acid are subjected to a docking reaction to obtain methyl carteolol. The new synthesis method of methyl carteolol described in the present invention has obvious advantages over the prior art, with high yield, environmental friendliness, complete reaction and fewer by-products.

The application relates to the field of enzyme engineering, and discloses an aminopeptidase mutant, a coding gene of the aminopeptidase mutant, a recombination carrier, a recombination strain and application of the aminopeptidase mutant, wherein the aminopeptidase mutant is an enzyme with at least one mutation of S88L, Y150C and Q268F in an amino acid sequence shown in SEQ ID NO:1. The aminopeptidase mutant can catalyze synthesis of L-carnosine from L-histidine in the presence of beta-alanine methyl ester, has high selectivity, high L-carnosine yield and low impurity content, and has the value of industrial application.

The present invention relates to a method for producing a dipeptide using a bioconversion process and, more specifically, to a method for producing L-alanyl-L-glutamine, the method comprising the steps of: (a) culturing a recombinant strain expressing the protein consisting of SEQ ID NO: 1; (b) mixing L-alanine methyl ester hydrochloride and glutamine with the culture; and (c) obtaining L-alanyl-L-glutamine.

The present invention relates to the technical field of pharmaceutical intermediate synthesis, and in particular to a method for synthesizing a sacubitril pharmaceutical intermediate. The synthetic route comprises reacting Compound II with Compound III in the presence of a catalyst to obtain a sacubitril intermediate, N-tert-butyloxycarbonyl-amino-4,4-biphenyl-R-alanine methyl ester, i.e., Compound I. This synthetic method eliminates the need for expensive and highly toxic trifluoromethanesulfonic anhydride and allows the synthesis of the target compound I in a single step. The experimental protocol employed in the present invention is simple to operate, employs mild reaction conditions, provides high yield and purity, and offers low cost, making it suitable for industrial scale-up production.

The invention discloses a method for catalytically preparing L-carnosine by using a yeast whole-cell catalyst, which comprises the following steps: adding the yeast whole-cell catalyst into a substrate solution containing 100mmol / L beta-alanine methyl ester and 200mmol / L L-histidine in a bioreactor, reacting for 60 minutes at 20 DEG C, maintaining the reaction pH to be 8.5 by using a 6mmol / L NaOH solution, and after the reaction is finished, separating and purifying to obtain the L-carnosine. The L-carnosine can be obtained; the yeast whole-cell catalyst is utilized to catalyze beta-alanine methyl ester and histidine to generate L-carnosine, and the whole-cell catalyst has the advantages of immobilized enzyme and can be repeatedly used, so that the problems of the existing biosynthesis method and chemical method are effectively solved, and the preparation process is simple and suitable for industrial production.

The invention relates to an enzymatic synthesis method of glutamine dipeptide, and belongs to the technical field of biosynthesis. In order to solve the problem of poor purity in the prior art, the invention provides an enzymatic synthesis method of N-(2)-L-alanyl-L-glutamine dipeptide, which is characterized by comprising the following steps: reacting L-glutamine with L-alanine methyl ester to obtain N-(2)-L-glutamine dipeptide by using alpha-ester acyltransferase which does not have signal peptide and has an amino acid sequence as shown in SEQ ID NO.1 or SEQ ID NO.3. The invention also provides an enzymatic synthesis method of N-(2)-L-glutamine dipeptide. The L-glutamine and L-alanine methyl ester can be effectively promoted to react so as to be converted into the L-glutamine dipeptide, the enzyme activity is high, the selectivity is high, the purity reaches 99% or above, and the yield reaches 80% or above.

The invention relates to a preparation method of (2R, 5R)-1, 2, 5-trimethylpiperazine. The preparation method comprises the following steps: sequentially adding Boc-N-methyl-D-alanine, D-alanine methyl ester hydrochloride, EDC.HCl, HOBT and DMF (Dimethyl Formamide) into a reaction flask, stirring for dissolving, activating carboxylic acid, and dropwise adding N-methylmorpholine; after the reaction is finished, adding ethyl acetate to dilute a reaction system, adding 1M hydrochloric acid for washing, layering and reserving an organic phase, and adding a saturated sodium bicarbonate solution for washing, layering and reserving an organic phase; adding saturated salt water for washing, layering, leaving an organic phase, and concentrating the organic phase; adding formic acid; adding sec-butyl alcohol and methylbenzene to neutralize the alkalinity in the crude product; dissolving with methylbenzene, dropwise adding a red aluminum solution, neutralizing, washing, layering, concentrating an organic phase to obtain a crude product, and purifying the crude product to obtain a finished product. The preparation method has the advantages that BOC-N-methyl-D-alanine and D-alanine methyl ester hydrochloride are taken as initial raw materials, the (2R, 5R)-1, 2, 5-trimethylpiperazine is obtained through the steps of condensation, cyclization and reduction, and the chiral purity of the (2R, 5R)-1, 2, 5-trimethylpiperazine is improved.

A system for the production of methotrexate amino acid methyl ester-loaded lipid nanocapsules (LNCs) for the treatment of methotrexate-resistant breast cancer cells, consisting of: a) a conjugate synthesis unit configured to synthesize methotrexate-amino acid methyl ester conjugates selected from the group consisting of methotrexate-alanine methyl ester (MAME), methotrexate-cysteine methyl ester (MCME), and methotrexate-aspartic acid methyl ester (MADE) conjugates; b) a nanocapsule manufacturing unit used to formulate lipid nanocapsules (LNCs) derived from MCME and MADE conjugates; c) a homogenization unit configured to process the lipid acid nanocapsules to obtain a uniform dispersion at the nanoscale; and d) a purification unit configured to purify the lipid nanocapsules.

The invention discloses a macrobrachium rosenbergii breeding seawater formula production process and a use method, and belongs to the technical field of aquaculture, the macrobrachium rosenbergii breeding seawater formula comprises sodium chloride, magnesium sulfate, anhydrous calcium chloride, potassium chloride, potassium bromide, boric acid and EDTA, the mass ratio of which is sequentially reduced; the composition further comprises a beta-alanine methyl ester derivative and isomaltitol. The beta-alanine methyl ester derivative contains a guanidyl structure. By adopting the macrobrachium rosenbergii fry breeding seawater formula, the technological process for preparing artificial seawater can be simplified, quality control is facilitated, the growth performance of macrobrachium rosenbergii can be improved, and the macrobrachium rosenbergii fry breeding seawater formula is suitable for application and popularization.

The invention provides a method for synthesizing a metalaxyl-M raw material by using a metalaxyl-M byproduct, and belongs to the technical field of medicament synthesis. The sodium benzenesulfonate wastewater is extracted to remove most organic matters, such as 2, 6-dimethylaniline, N-(2, 6-dimethylphenyl)-R-alanine methyl ester and the like, and then the impurities in the sodium benzenesulfonate wastewater can be further removed by evaporative crystallization, so that the purification of sodium benzenesulfonate is realized, and the quality of the sodium benzenesulfonate wastewater is improved. Then sodium benzenesulfonate and a chlorination reagent are subjected to an acylating chlorination reaction to generate metalaxyl-M raw material benzenesulfonyl chloride, and resource utilization is achieved; according to the method, the sodium benzenesulfonate wastewater is dehydrated and then subjected to the acylating chlorination reaction with the chlorination reagent to generate the metalaxyl-M raw material benzenesulfonyl chloride, so that resource utilization is realized, and meanwhile, cyclic utilization of resources is realized.

The utility model relates to a rotary evaporation device for preparing L-phenylalanine methyl ester hydrochloride, and aims to solve the technical problems that in the rotary evaporation preparation process of L-phenylalanine methyl ester hydrochloride at present, an operator needs to continuously add liquid into a water bath kettle, and stability and safety are poor after a collecting bottle and a second bottle opening connector are installed. A water bath kettle is installed on one side of the surface of the base, a carrier plate is installed on one side of the water bath kettle, a liquid level adjusting pipe is fixedly connected to the top end of the carrier plate, a liquid conveying tank is connected to one end of the liquid level adjusting pipe in a sealed mode, and a liquid guide pipe is connected to the other end of the liquid level adjusting pipe in a sealed mode. According to the L-phenylalanine methyl ester hydrochloride rotary evaporation device, a proper amount of liquid is automatically added into the water bath kettle of the rotary evaporation device, the situation that an operator continuously adds the liquid into the water bath kettle in the rotary evaporation preparation process of L-phenylalanine methyl ester hydrochloride is avoided, and the convenience of the rotary evaporation device in the use process is improved.

The invention provides aminopeptidase as well as a preparation method and application thereof, and belongs to the technical field of biocatalysts. Escherichia coli cells which contain recombinant expression vectors or are integrated with exogenous nucleic acid corresponding to SEQ ID NO: 1 in genomes are used as host cells, and aminopeptidase containing the sequence SEQ ID NO: 2 is induced and expressed by the host cells. The obtained aminopeptidase has the advantages of high enzymatic activity, high enzymatic reaction level and the like, and can be used for converting beta-alanine methyl ester hydrochloride into L-carnosine when the concentration of a conversion substrate L-histidine is 70g / L.

This invention relates to an amino acid ester acyltransferase mutant, its encoding gene, and its application in the synthesis of glutamic-alanine dipeptide. Compared with existing technologies, the amino acid ester acyltransferase mutant disclosed in this invention exhibits high activity, high substrate concentration tolerance, and high selectivity for glutamic-alanine dipeptide synthesis / hydrolysis. In the application of catalyzing the condensation of L-alanine methyl ester and L-glutamine to prepare glutamic-alanine dipeptide, it demonstrates significant advantages in terms of high yield and high space-time yield. Compared with chemical synthesis methods, the synthesis of glutamic-alanine dipeptide using this enzyme does not require group protection and deprotection, the process is simple, the reaction conditions are mild, and the process is environmentally friendly, showing promising application prospects in the industrial production of glutamic-alanine dipeptide.

The invention discloses a synthetic method of a natural product linear pentapeptide AYAPE and a cyclic pentapeptide Cyclo-AYAPE.The method comprises the steps that known L-alanine methyl ester and L-N-Fmoc-O-tert-butyl ether tyrosine serve as initial raw materials, condensation is conducted, and then methyl ester hydrolysis is conducted to obtain dipeptide; l-N-Boc-proline and glutamic acid tert-butyl ester methyl ester are condensed, methyl ester is hydrolyzed to obtain dipeptide, the dipeptide and the dipeptide are condensed to obtain tetrapeptide, Fmoc protecting groups of the tetrapeptide are removed, the tetrapeptide and L-N-Fmoc alanine are condensed to obtain pentapeptide, all protecting groups of the pentapeptide are removed, and linear pentapeptide AYAPE is obtained; and carrying out self condensation on the obtained pentapeptide to form the cyclic pentapeptide Cyclo-AYAPE. The synthesis method is low in cost, simple and convenient to operate, mild in reaction condition, short in reaction route, high in total yield and suitable for large-scale synthesis of the linear pentapeptide AYAPE and the cyclic pentapeptide Cyclo-AYAPE of the linear pentapeptide AYAPE, and an important material basis is provided for biological activity evaluation of the natural product linear pentapeptide AYAPE and the cyclic pentapeptide Cyclo-AYAPE of the linear pentapeptide AYAPE.