85 results about "Alanine methyl ester" patented technology

The invention relates to an alanine substituted calix[4]arene bonded silica stationary phase and a preparation method and application thereof. According to the invention, gamma-aminopropyl trimethoxy silane is used as a coupling agent and reacts with specially-produced silica gel under the protection of triethylamine and inert gas so as to prepare gamma-aminopropyl trimethoxy bonded silica which reacts with 25,27-di(L-alanine methyl ester-N-carbonyl-methoxy)-26,28-dihydroxy-p-tert-bytyl-calix[4]arene under the protection of triethylamine and inert gas so as to prepare the alanine substituted calix[4]arene bonded silica stationary phase. The alanine substituted calix[4]arene bonded silica stationary phase prepared in the invention has the advantages of high bonded amount, stable performance and better separation selectivity, has same performance as traditional ODS reversed phase chromatography does, provides a plurality of action sites for inclusion, complexation, hydrogen bonding, etc. and is advantageous in separation of specific substances difficult to separate.

The invention provides a preparation method and technological system for enzymatically synthesizing N(2)-L-alanyl-L-glutamine. The preparation method comprises the steps of synthesis of L-alanine methyl ester, synthesis of N(2)-L-alanyl-L-glutamine, inactivation of enzymes, filtration, preparation of a crude product I of N(2)-L-alanyl-L-glutamine and preparation of a crude product II of N(2)-L-alanyl-L-glutamine. The technological system also comprises a production line formed by an L-alanine methyl ester synthesis kettle (1), an L-alanine methyl ester storage tank (2), an N(2)-L-alanyl-L-glutamine synthesis reaction kettle (3), an enzyme storage tank (4), a storage tank (5), a resin column (6) and mother liquor recovery tanks (7). The preparation method and the technological system have the technical effects that impurities are effectively removed, thus improving the purity of a finished product; the requirements for equipment are simple; the yield is high, after-treatment is simple to carry out, and the cost is low.

The invention discloses a method of producing L-alanyl-L-glutamine from recombinant escherichia coli, wherein the method of producing L-alanyl-L-glutamine from recombinant escherichia coli is follows: in an aqueous solution with a determined pH value, acting on free L-glutamine and L-alanine methyl ester hydrochloride to generate L-alanyl-L-glutamine, recombining a gene segment of the protein with the amino-acid ester acyltransferase of the L-alanyl-L-glutamine into a carrier and transferring into host bacteria, thereby obtaining the host bacteria with the recombinant DNA and capable of strengthening the activity of an L-alanyl-L-glutamine biological synthesis system. The method comprises the following steps: (1) culturing a larger number of recombinant escherichia coli cells for expressing the amino-acid ester acyltransferase; (2) excessively expressing the amino-acid ester acyltransferase in the step (1); and (3) taking the amino-acid ester acyltransferase in the step (2) as a crude enzyme source, adding the crude enzyme source into a buffer solution containing L-glutamine and L-alanine methyl ester hydrochloride substrate amino acid to react, thereby realizing efficient production of the L-alanyl-L-glutamine.

The invention discloses an HPLC (high performance liquid chromatography) detection method for simultaneously determining five substances (L-Ala-L-Gln (L-alanyl-L-glutamine), L-Gln, L-AlaOMe, L-Glu and L-alanyl-L-alanine) in a reaction system for producing L-Ala-L-Gln with a microbial enzyme method. The five substances are subjected to pre-column automatic derivatization treatment by ortho-phthaladehyde, so that the five substances have fluorescence groups and are detected by a fluorescence detector. The chromatographic condition is as follows: a high performance liquid chromatograph Agilent 1260 Infinity is adopted; an Agilent ZORBAX SB-Aq, 5 mu m, 4.6*250 mm C18 column is adopted as a chromatographic column; an Agilent 1260 Infinity fluorescence detector is adopted; a mobile phase comprises acetonitrile and a phosphate buffer solution in the volume ratio being 12:88, and the pH of the mobile phase is adjusted to 7.4 by the aid of phosphoric acid; the flow velocity of the mobile phase is 1.0 ml / min; the column room temperature is 40 DEG C; detection wavelength comprises excitation wavelength Ex 338 nm and emission wavelength Em 450 nm. The method realizes simultaneous determination of oligopeptide, amino acid and amino derivatives, is simple to operate and high in sensitivity and has important application value.

The invention provides a method for preparing N-acetyl-beta-chlorine-L-alanine methyl ester. The method includes the steps that (a) serine serves as a starting material and is esterified through methanol or ethyl alcohol, (b) the esterified matter is chlorinated through sulfoxide chloride, (c) the chlorinated matter undergoes acylation, (d) the acylated matter is recrystallized, and accordingly the N-acetyl-beta-chlorine-L-alanine methyl ester is obtained. The method is high in reaction yield, by-products are few, reaction mother liquor is recycled and reused, distilled liquid obtained after acylation is acetic acid and acetic anhydride, and the liquid is recycled and reused after being purified. Accordingly, cost is low, tail gas generated in reactions is absorbed through strong-base solutions to form salt and then is separated and used, and accordingly environment protection is achieved.

The invention provides a chiral N-heterocyclic carbene precursor salt with a 3,4-dihydroisoquinoline skeleton, a synthetic method and application. The precursor salt has the structural formula as shown in the specification. The precursor salt can be prepared by using cheap and readily available chiral phenylalanine methyl ester hydrochloride as a starting material, has good application in the asymmetric reaction under the catalysis of N-heterocyclic carbene, and can be used for synthesizing naphthopyrone compounds with high enantioselectivity.

The invention discloses a strong-adsorption salt-resistant plugging agent based on nano silicon dioxide and a water-based drilling fluid, and belongs to the technical field of oil and gas field drilling. The strong-adsorption salt-resistant blocking agent based on nano-silica is prepared from nano-silica, an amino-containing silane coupling agent, D-alanine methyl ester hydrochloride, a double-bond-containing chloro compound and an amine compound containing a sulfonic acid functional group through a step-by-step method, and contains a quaternary ammonium functional group and a sulfonic acid functional group, the adsorption performance and the temperature-resistant and salt-resistant performance are relatively high. The synthetic raw materials of the blocking agent are easy to obtain, and the synthetic method is simple and reliable. The particle size distribution of the synthesized strong-adsorption salt-resistant plugging agent based on nano-silica is 146-843 nm, and nano-scale apertures in a shale well wall can be effectively plugged. The plugging agent can be directly added into the water-based drilling fluid, is good in compatibility, can effectively prevent the drilling fluid from permeating into a stratum so as to stabilize a well wall and prevent collapse, and has good plugging and filtrate reduction effects.

The invention provides an injected amino acid derivative micromolecule gel material and application thereof, and belongs to the field of biomedical engineering in material chemistry. A preparation method comprises the following steps that first, phenylalanie methyl ester (D / L type) is regarded as a reaction zymolyte, and is modified by 1,4-naphthalic acid (NDC) and diethylene glycol, and amino acid derivative micromolecule gelator NDC-L or / and D-PhOMe, NDC-L or / and D-PhOH; and then, the gelator is added into polyethylene glycol, and heated to be completely dissolved, then equivoluminal deionized water is added, and after mixing, the injected amino acid derivative micromolecule gel material is obtained for several-minute standing. According to the injected amino acid derivative micromolecule gel material and the application thereof, a procedure is relatively simple, operation is convenient, the prepared gel material after freezing and drying is of a three-dimension (or nostoc commune) structure, biocompatibility is good, degradation is easy, the slow-release effect of medicine vitamin B12 is excellent, the gel material can be regarded as a medicine support or vector used for clinic treatment, and great practical prospects are achieved.

The invention provides a modification method on the basis of crosslinking reaction between laccase amino acid residue terminal carboxyl group (-COOH) and amino group of methyl L-phenylalaninate hydrochloride to enhance activity and stability of the laccase, which comprises the following step: mixing laccase, methyl L-phenylalaninate hydrochloride and 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride at a certain temperature to react to obtain the modified laccase. Compared with the unmodified laccase, the modified laccase has higher activity and stability. The modified laccase can be used for aftergrowth fiber modification, and can save the laccase consumption on the premise of enhancing the strength property of the paper sheets made from aftergrowth fibers.

The invention relates to an organic porous gel absorbent for quick treatment of dye wastewater in printing and dyeing industry, a preparation method and application of the organic porous gel absorbent. The organic porous gel absorbent is 1,4-phenyl phenylalanine. The preparation method comprises the steps of preparing 1,4-phenyl phenylalanine methyl ester from phthaloyl chloride, L-phenylalanine methyl ester hydrochloride and triethylamine; and preparing the dyeing absorbent 1,4-phenyl phenylalanine from 1,4-phenyl phenylalanine methyl ester. The invention also relates to the application of the organic porous gel absorbent as a quick absorbent in dye wastewater treatment. The organic porous gel absorbent provided by the invention is a low-molecular-weight gel absorbent with an active carbon porous structure, and can rapidly and efficiently capture dyes in the industrial wastewater through phi-phi interaction, with the advantages of easy recovery and low cost. The dye adsorption can beconducted by simple operation at normal temperature, so that the organic porous gel absorbent has actual application value.

The invention relates to metabolites of Ridomil in ctenopharyngodon idellus. The metabolites of Ridomil in ctenopharyngodon idellus can be N-(2-carboxyl-6-benzyl)-N-(methoxyacetyl)alanine, N-(2-hydroxymethyl)-6-tolyl-N-(glycolyl)alanine, N-(2, 6-xylyl)-N-(glycolyl)alanine or N-(2-hydroxymethyl-6-benzyl)-N-(methoxyacetyl)alanine methyl ester. After dosing ctenopharyngodon idellus with Ridomil, the invention for the first time finds that in a mouth filling group and a soaking group, Ridomil in liver tissue is based on prototype drug, and finds the metabolites of the aforementioned four Ridomil in ctenopharyngodon idellus.

The invention discloses a method for improving activity of an L-alanyl-L-glutamine biosynthesis system containing recombinant DNA. A recombinant plasmid of the recombinant escherichia coli comprises an amino-acid ester acyltransferase encoding gene (SAET) which can catalyze L-glutamine and L-alanine methyl ester hydrochloride to generate L-alanyl-L-glutamine, and a multidrug efflux transporter protein encoding gene (ydeE) which can transporting L-alanyl-L-glutamine outside cells from cells, and due to co-expression of the two encoding genes, stability of a bacterium can be effectively improved, and the yield and the transformation rate of the bacterium can be increased. The recombinant plasmid is obtained by recombining SAET and ydeE with the same plasmid, or by co-transforming two recombinant plasmids with different resistances of two genes respectively. The yield of L-alanyl-L-glutamine of the recombinant bacterium can be increased by 3.33 times when compared with a conventional yield.

The invention discloses a synthesis method of optically active metalaxyl. The optically active metalaxyl is synthesized by performing methoxylation and acylating chlorination on chloroacetic acid to obtain methoxyacetyl chloride and then reacting Methoxyacetyl chloride with D-N-(2,6-dimethylphenyl) alanine methyl ester; a one-pot method operation is adopted for the synthesis; the two-step reactionof methoxylation and acylating chlorination is directly used for a next-step reaction without post-treatment. According to the process of the optically active metalaxyl, by adopting the one-pot method operation, the operation steps are simplified, the production of three wastes is decreased, the synthesis cost is reduced, the obtained product is stable in quality and relatively high in output andyield, and the synthesis method is suitable for large-scale production.

The invention discloses application of amino acid ester compounds in the preparation of anti-CVB3 (anti-coxsackie B virus 3) drugs and belongs to the technical field of antiviral drugs. Verification by massive biological experiments shows that amino acid ester compounds (glycine ethyl ester, L-leucine methyl ester, L-alanine methyl ester, tert-butyl L-alaninate, beta-alanine ethyl ester, D-leucinemethyl ester, tert-butyl glycinate, beta-alanine tert-butyl ester, and L-leucine tert-butyl ester) can inhibit replication and proliferation of CVB3 in cells, can strongly inhibit cytopathic effect due to CVB3 and increase the survival rate of infected cells, and is applicable to the preparation of anti-CVB3 drugs or drugs to treat diseases due to CVB3 infections. Novel pharmaceutical applicationof amino acid ester compounds is discovered herein, and a new direction is provided for the development of anti-CVB3 drugs.

The invention relates to a bactericidal active ingredient composition, and particularly relates to a new bactericidal active composition which comprises active ingredients of pyraclostrobin, ipconazole and metalaxyl. The composition is very suitable for preventing plant pathomycete and bacteria. The bactericidal active ingredient composition is characterized by comprising the following active ingredients: (a) methyl (N)-[[[1-(4-chlorobenzene) pyrazol-3 group)-oxygen]-0-methoxy group]-N- methoxy-carbamic acid ester; (b) (1RS, 2SR, 5RS; 1RS, 2SR, 5SR)-2-(4-chlorine benzyl)-5- isopropyl-1-(1H-1, 2, 4-triazole-1-group methyl) cyclopentanol; (c) D,L-N-(2, 6- dimethyl phenyl)-N-(2-methoxy group acetyl) alanine methyl ester, wherein the mass ratio of the ingredients (a) (b) and (c) is (1-50): (1-50): (1-50).

The invention relates to a synthesis method of L-dopa methyl ester hydrochloride, which comprises the following steps: by using veratone as a raw material, carrying out amidation to obtain 2-amino-3-(3,4-dimethoxyphenyl)propanamide, carrying out amide oxidation into carboxy group to obtain 2-amino-3-(3,4-dimethoxyphenyl)propionic acid, removing methoxy group to obtain 2-amino-3-(3,4-dihydroxyphenyl)propionic acid, and finally, carrying out methyl ester conversion and acidification to obtain the target product 2-amino-3-(3,4-dimethoxyphenyl)alanine methyl ester hydrochloric acid. The method has the advantages of accessible reaction raw materials, ingenious technique concept, simple steps and no use of virulent reagents, is simple to operate, conforms to the requirements for green chemical industry, and is suitable for industrial production.

The invention discloses a synthesis method of a beta-alanine methyl ester salt product, and relates to the technical field of beta-alanine methyl ester salt production. The method includes the following steps of firstly, adding beta-alanine to methyl alcohol to be stirred, and adding concentrated sulfuric acid; secondly, conducting backflow after feeding of concentrated sulfuric acid ends; thirdly, concentrating a methyl alcohol solution of beta-alanine methyl ester salt; fourthly, adding the concentrated solution to purified water to be evenly stirred, adjusting the PH of a water solution of beta-alanine methyl ester salt through ammonium hydroxide, and storing the prepared water solution of beta-alanine methyl ester salt at low temperature. The method has the advantages of being high in yield, easy to operate and easy to control; the method is free of toxic and corrosive gases in the synthesis process, small in environment pollution and beneficial to large-scale production.

The invention discloses a preparation method of N-(pyrazine-2-radical carbonyl)-L-phenyl alanine. The preparation method comprises the following steps of: (1) making thionyl chloride react with pyrazine-2-formic acid in an organic solvent to obtain pyrazine-2-formyl chloride; (2) making thionyl chloride react with L-phenyl alanine in methanol to obtain L-phenyl alanine methyl ester hydrochloride; (3) dissolving pyrazine-2-formyl chloride and a metal M in tetrahydrofuran and adding the solution into a tetrahydrofuran solution of the L-phenyl alanine methyl ester hydrochloride and the metal M to obtain N-(pyrazine-2-radical carbonyl)-L-phenyl alanine methyl ester; and (4) dissolving the N-(pyrazine-2-radical carbonyl)-L-phenyl alanine methyl ester in an organic solvent and hydrolyzing under an alkaline condition to obtain N-(pyrazine-2-radical carbonyl)-L-phenyl alanine. A synthetic method has the advantages of less operation steps, high yield, readily-available raw materials and low environmental pollution, and is suitable for industrial production.

The invention discloses a method for efficiently catalyzing and synthesizing L-carnosine in a whole cell. The method comprises the following steps of 1) constructing a recombinant vector containing anamino acid fatty acyltransferase gene with a nucleotide sequence shown in SEQ ID NO.1, wherein the amino acid sequence encoded by the gene is shown in SEQ ID NO. 2; 2) transferring a gene with a nucleotide sequence shown in SEQ ID NO.1 to bacterium coli to obtain recombinant bacterium coli; 3) dissolving a substrate beta-alanine methyl ester and L-histidine in a buffer solution, wherein the pH is7.5-9.5; 4) adding the recombinant bacterium coli to the buffer solution for reaction, wherein the reaction temperature is 25-42 DEG C. A recombinant plasmid and recombinant engineered bacteria of the gene directly catalyze and synthesize the L-carnosine in the catalytic system, thereby improving the conversion rate of the L-carnosine, and the problems of the complicated separation and purification of an enzyme and the high cost of an aminopeptidase catalytic process are solved.

The invention discloses a method for synthesizing an AHU377 calcium salt. The method comprises the following steps: reacting 4-bromo-D-phenylalanine with thionyl chloride, reacting obtained methyl 4-bromo-D-phenylalaninate hydrochloride with BOC acid anhydride, reacting the obtained reaction product with phenylmagnesium bromide to obtain N-tert-butyloxycarbonyl-amino-4,4-biphenyl-R-alanine methylester, reacting the N-tert-butyloxycarbonyl-amino-4,4-biphenyl-R-alanine methyl ester with sodium borohydride, reacting the obtained reaction product with ethyl 2-(triphenylphosphoranylidene)propionate to obtain ethyl (4R)-5-[1,1'-biphenyl]-4-yl-4-[[tert-butoxycarbonyl]amino]-2-methyl-2-pentenoate, reacting the ethyl (4R)-5-[1,1'-biphenyl]-4-yl-4-[[tert-butoxycarbonyl]amino]-2-methyl-2-pentenoatewith lithium hydroxide, performing catalytic hydrogenation, reacting the obtained catalytic hydrogenation product with thionyl chloride to obtain ethyl (2R, 4S)-5- ([1,1-biphenyl)-4-amino-2-methylpentenoate hydrochloride, and stirring and reacting the ethyl (2R, 4S)-5- ([1,1-biphenyl)-4-amino-2-methylpentenoate hydrochloride, calcium chloride and succinic anhydride to obtain the target product.The method has the advantages of simple steps, mild reaction conditions, high purity and high yield.

The invention discloses a liquid-phase synthesis method for cyclic peptides Alaptide. The liquid-phase synthesis method includes carrying out reaction on L-cycloleucine with Boc protected N ends, N-hydroxysuccinimide and N, N'-dicyclohexylcarbodiimide by the aid of Boc strategies of liquid-phase synthesis processes so as to obtain active ester; carrying out condensation on the active ester and hydrochloride of alanine methyl ester to obtain cyclo-leucyl alanine methyl ester with Boc protected N ends; removing Boc protecting groups; carrying out cyclization reaction on amine and carboxylate ester under alkaline conditions to obtain the cyclic peptides Alaptide. The liquid-phase synthesis method has the advantages that the liquid-phase synthesis method includes simple operation steps and islow in cost and high in product yield, and the problems of high material cost and environmental stress, low product yield, difficulty in scale expansion and the like of existing synthesis methods canbe solved.

The invention discloses a temperature-sensitive spiral polyisocyanide derivative constructed by a dynamic acylhydrazone bond and a preparation method thereof. The structural formula of the spiral polyisocyanide derivative is shown as the specification, wherein m = 0.9-0.95, and n = 1-m. The group R is dimethyl glutamate (Glu), alanine methyl ester (Ala), phenylalanine methyl ester (Phe) or leucinemethyl ester (Leu). According to the invention, the spiral conformation of the main chain is induced by using a small amount of chiral glutamic acid or other small molecules of amino acids with aldehyde groups by utilizing the principle of general-soldier, wherein the polyisocyanide derivative has excellent temperature-sensitive characteristics, and the polymer spiral conformation can be regulated and controlled through the temperature-sensitive phase change behavior. In addition, the orderliness of the spiral conformation also influences the temperature-sensitive behavior of the polymer. Theinvention of the novel polyisocyanide derivative provides a new thought for preparing a stimuli-responsive chiral material, and expands the application prospect of the polyisocyanide derivative in the field of intelligent materials.

The invention discloses a synthetic method of 3-chloro-L-alanine methyl ester hydrochloride. The method comprises the following steps: adding L-serine into a first solvent, performing cooling to 5-10DEG C, adding thionyl chloride A dropwise, performing heating to 38 DEG C after adding is completed, performing a reaction for 48 h, performing cooling crystallization on the mixture, performing centrifugation and performing drying to obtain L-serine methyl ester hydrochloride; and adding the L-serine methyl ester hydrochloride into a second solvent, adding thionyl chloride B dropwise, performinga sectional temperature control reaction, performing cooling to 15-25 DEG C after the reaction is finished, adding water for layering, and treating the obtained water phase to obtain the 3-chloro-L-alanine methyl ester hydrochloride. By adopting the sectional temperature control mode, the method has the advantages of short reaction time, mild reaction conditions, a high yield and fewer byproducts,and is convenient for enhancing the yield and product purity; the L-serine methyl ester hydrochloride does not need to be purified, so that the process is optimized; and water is added for layering,an organic phase is extracted for multiple times, adsorption is performed by activated carbon in a water phase, so that the product yield and the product purity are further improved.

The invention discloses a hexavanadate-L-alanine methyl ester derivative and a preparation method and application of the hexavanadate-L-alanine methyl ester derivative, and belongs to the technical field of organic and inorganic hybrid materials. The hexavanadate-L-alanine methyl ester derivative has an anti-tumor activity, the structural formula is [Bu4N]2[V6O13]{(OCH2)3CCH2OOCCH2CH2CONHCH(CH3)CH2COOCH3}2]; the preparation method comprises the following steps: adding 1-(3-dimethyl aminopropyl)-3-ethylenediamine hydrochloride, 1-hydroxybenzotriazole, L-D-alanine methyl ester hydrochloride andtrimethylamine into an acetonitrile solution of the hexavanadate succinic acid derivative, dissolving, and reacting for 40-50 hours at the temperature of 48-52 DEG C to obtain the hexavanadate-L-alanine methyl ester derivative. The hexavanadate-L-alanine methyl ester derivative has an important research value and application prospect in the fields of pharmaceutical chemistry, and further providesa direction for the development of medicines.

The invention relates to an organic porous gel absorbent for quick treatment of dye wastewater in printing and dyeing industry, a preparation method and application of the organic porous gel absorbent. The organic porous gel absorbent is 1,4-phenyl phenylalanine. The preparation method comprises the steps of preparing 1,4-phenyl phenylalanine methyl ester from phthaloyl chloride, L-phenylalanine methyl ester hydrochloride and triethylamine; and preparing the dyeing absorbent 1,4-phenyl phenylalanine from 1,4-phenyl phenylalanine methyl ester. The invention also relates to the application of the organic porous gel absorbent as a quick absorbent in dye wastewater treatment. The organic porous gel absorbent provided by the invention is a low-molecular-weight gel absorbent with an active carbon porous structure, and can rapidly and efficiently capture dyes in the industrial wastewater through phi-phi interaction, with the advantages of easy recovery and low cost. The dye adsorption can beconducted by simple operation at normal temperature, so that the organic porous gel absorbent has actual application value.

The invention relates to a synthetic method for N-acetyl carnosine comprising using [beta]-alanine methyl ester as an initial raw material, raising the dissolvability of [beta]-alanine methyl ester in an organic solvent and reducing the dissolvability in water, by modifying the amino group into 2,4,6-trimethoxy benzal group, hydrolyzing to remove methyl ester after acetylating the amino group, carrying out a condensation reaction with histidine methyl ester, protecting by a strong acid after hydrolyzing to remove methyl ester, absorbing by a strong acid cation resin, eluting by ammonia water to obtain N-acetyl carnosine. Compared with the prior art, the synthetic method for N-acetyl carnosine can effectively overcome the problems of difficulty of separating intermediates and usage of expensive raw material carnosine, and another synthetic method for N-acetyl carnosine is provided.

The present invention discloses a whole-cell one-step method for synthesizing L-carnosine. The whole-cell one-step method comprises the following steps: 1) a recombinant vector is constructed, the recombinant vector contains an amino acid fatty acyltransferase gene having a nucleotide sequence shown in SEQ ID NO.1, and an amino acid sequence encoded by the gene is shown in SEQ ID NO.2; 2) the genehaving the nucleotide sequence shown in the SEQ ID NO.1 is transferred into Escherichia coli to obtain recombinant Escherichia coli; 3) substrates of beta-alanine methyl ester and L-histidine are dissolved in a buffer solution, and pH is 7.5-9.5; and 4) the recombinant Escherichia coli is added to the buffer solution for reaction at a reaction temperature of 25-42 DEG C. Recombinant plasmids andrecombinant engineering bacteria of the gene are utilized to directly catalyze synthesis of the L-carnosine in a catalytic system, and the method improves conversion rate of the L-carnosine, and at the same time solves problems of complicated separation and purification of enzymes and high cost of an aminopeptidase catalytic process.

The invention discloses a time resolution fluorescent immunochromatographic test strip for detecting metalaxyl, and a preparation method and application thereof. The time resolution fluorescent immunochromatographic test strip comprises a bottom plate and further comprises a sample absorbent pad, a combination releasing pad, a nitrocellulose membrane and a water absorbent pad which are lapped andpasted on the bottom plate in sequence. A metalaxyl monoclonal antibody labelled by fluorescent microspheres is embedded into the combination releasing pad, and a detecting area and a quality controlarea are fixed to the nitrocellulose membrane. A metalaxyl hapten-carrier protein conjugate is sprayed in the detecting area, an anti-sheep and anti-mouse antibody is sprayed in the quality control area, and a metalaxyl hapten is obtained in the modes that N-(2,6-dimethyl phenyl) alanine methyl ester reacts with (4-nitrophenoxy) acetylchloride to generate nitrobenzene metalaxyl, and then the nitrobenzene metalaxyl is subjected to zinc powder reduction. The time resolution fluorescent immunochromatographic test strip and a detecting method provided by the invention have the advantages that operation is easy, sensitivity is high, the detecting speed is high, and the cost is low, and the metalaxyl in large-batch samples can be detected quickly and monitored on site.

The invention discloses a betulinic acid-amino acid derivative represented by a formula (I) and a preparation method thereof. The preparation method comprises the following steps of carrying out acylation reaction on a compound represented by a formula (a), acetic anhydride and pyridine under the protection of nitrogen so as to obtain a compound represented by a formula (b), reacting the compound of the formula (b) with oxalyl chloride so as to obtain a compound represented by a formula (c), then, respectively reacting the compound of the formula (c) with glycino methyl ester, L-alanine methyl ester, L-valine methyl ester, L-isoleucine methyl ester and L-glutamic acid methyl ester so as to obtain a compound represented by a formula (d), and washing, drying and purifying after reacting the compound of the formula (d) with LiOH so as to obtain the betulinic acid-amino acid derivative represented by the formula (I). The preparation method is high in synthetic efficiency and simple and convenient in process. The invention further discloses application of the betulinic acid-amino acid derivative represented by the formula (I) in preparation of a drug for treating osteoporosis; and the betulinic acid-amino acid derivative can be used as an osteoclast precursor differentiation inhibitor and has the obviously increased osteoclast precursor differentiation activity inhibition effect.