11 results about "Alanine methyl ester" patented technology

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 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 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 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 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 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.

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 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.

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.