32 results about "N-pentanoic acid" patented technology

The invention discloses a preparation method of a portable paper-based ratiometric fluorescence sensor APBA-CsPbBr3 at-UiO-66 / Ru, which comprises the following steps: 1, adding lead bromide and cesium bromide into N, N-dimethylformamide, then adding 5-bromovaleric acid and an oleylamine ligand, and stirring; 2, perfluorooctyltriethoxysilane is added, and a precursor solution is obtained; 3, adding zirconium chloride and terephthalic acid into N, N-dimethylformamide to obtain a homogeneous solution; 4, after heating, UiO-66 is obtained; 5, stirring the precursor solution, APBA, UiO-66 and tris (2, 2-dipyridyl) ruthenium chloride hexahydrate to obtain a composite material; and 6, dropwise adding the composite material solution into the filter paper. The APBA modified material is adopted as a recognition unit, the APBA modified material and the paper base construct a fluorescence sensing platform, visual quantitative analysis of oxytetracycline in water is achieved, and the device is convenient to carry, low in detection limit, high in anti-interference performance, easy and convenient to operate and suitable for on-site rapid detection of oxytetracycline.

To provide a composition with effects in enhancing muscle strength and motor function.SOLUTION: A composition comprises a processed plant material comprising diosgenin and 3-hydroxyisovaleric acid or a salt thereof, or derivatives thereof.SELECTED DRAWING: Figure 2

The invention discloses a photovoltaic adhesive film with low shrinkage and a preparation method thereof, and belongs to the technical field of photovoltaic film adhesive preparation. The photovoltaic adhesive film with low shrinkage is composed of the following components in parts by weight: 15-18 parts of ethylene-acrylic acid copolymer, 35-42 parts of ethylene-vinyl acetate copolymer, 1.5-1.8 parts of cross-linking agent, 0.7-1.3 parts of silane coupling agent, 1.1-2.7 parts of composite light stabilizer, 1.2-2.4 parts of composite modifier, wherein the composite light stabilizer is prepared by morpholine dichloride, N-butyl-2,2,6,6-tetramethyl-4-piperidinamine, N-(4-aminophenyl) maleimide and tetrakis (3-mercaptobutyric acid) pentaerythritol ester, and the composite modifier is prepared by dimethylaminoethyl methacrylate, azobisisoheptonitrile, 4-cyano-4-(thiobenzoylthio) valeric acid. The prepared photovoltaic adhesive film has low shrinkage, excellent aging resistance and mechanical properties.

The invention provides recombinant halomonas, a construction method of the recombinant halomonas and application of the recombinant halomonas in production of polyhydroxyalkanoate. The recombinant halomonas is used for expressing the 2-keto acid decarboxylase or the 2-keto acid decarboxylase mutant. According to the invention, a 2-ketonic acid decarboxylase mediated 3HV synthesis path is constructed, alpha-ketoglutaric acid in tricarboxylic acid circulation can be directly converted into 3-hydroxyvaleryl coenzyme A, de novo synthesis of a 3HV monomer is realized, a conventional carbon source can be efficiently utilized to synthesize 3HV, and the traditional technical bottleneck of dependence on an exogenous propionic acid or valeric acid precursor is broken through; the 3HV with a higher proportion can be obtained by regulating and controlling a metabolic pathway under the condition of not adding an exogenous precursor, so that the fermentation process is remarkably simplified, and the raw material cost and the production complexity are reduced.

The invention belongs to the technical field of organic chemical engineering, and particularly relates to a method for preparing a biotin key intermediate through fixed bed continuous catalytic hydrogenation. A solution containing (3aS, 6aR)-1, 3-dibenzyl-tetrahydro-1H-thieno [3, 4-d] imidazol-2 (1H)-ketone-4-enolefine valeric acid (II) and hydrogen are conveyed to a mixer at the same time and then enter a fixed bed reactor filled with Raney nickel to be subjected to a continuous high-stereoselectivity catalytic hydrogenation reaction, an outlet of the fixed bed is connected to a back pressure valve through a pipeline, and then reaction liquid flows out; and (3aS, 6aR)-1, 3-dibenzyl-tetrahydro-1H-thieno [3, 4-d] imidazol-2 (1H)-ketone-4-valeric acid (I) is obtained after purification is carried out. The method provided by the invention overcomes the defects in the prior art, has the advantages of good selectivity, high yield, short reaction time, easy separation and high efficiency, and is suitable for industrial amplification application.

The invention provides a combined grinding aid as well as a preparation method and application thereof, and belongs to the technical field of ore grinding. The combined grinding aid is prepared from the following raw materials in parts by weight: 20 to 30 parts of sodium hexametaphosphate, 6 to 8 parts of 2-methylvaleric acid, 3 to 5 parts of cinnamyl propionate and 3 to 5 parts of alkalized molasses. According to the obtained combined grinding aid, the grinding efficiency of quartz can be greatly improved, the content of particles with the particle size being-0.043 mm can reach 85% or above, the usage amount of the grinding aid is very low, and good economical efficiency is achieved; meanwhile, after the combined grinding aid is used for ore grinding, the recovery rate of subsequent flotation of quartz can be increased.

A process for the preparation of isoprenol comprises the steps of a-i) preparing isobutylene by oxidizing isoamyl alcohol to isovaleric acid, and subjecting the isovaleric acid to oxidative decarboxylation so as to obtain isobutylene; and a-ii) reacting at least one formaldehyde source and the isobutylene obtained in step a-i) to obtain isoprenol. The process allows for providing isobutylene for the preparation of isoprenol and its downstream products, including prenol, prenal, isoprenal and / or 3,7-dimethyl-octa-2,6-dienal (citral), from renewable sources.

The invention discloses an extraction agent as well as a preparation method and application thereof. The extraction agent comprises a phosphorus or phosphine compound extraction agent and an extraction inhibitor, the extraction inhibitor is a weak acid compound selected from nonyl phenol, octyl phenol, 3, 5-di-tert-butyl catechol, 4-tert-butyl catechol, 4-butyl catechol, capryloyl salicylic acid, azelaic acid, sebacic acid, dodecanedioic acid, 2-hexyldecanoic acid, lauric acid, decanoic acid, 2, 2 '-(1, 4-phenylene bis (oxy)) dibutyric acid, 2, 2'-(1, 4-phenylene bis (oxy)) divaleric acid, 2, 2 '-(1, 4-phenylene bis (oxy)) divaleric acid, 2, 2'-(1, 4-phenylene bis (oxy)) dibutyric acid, 2, 2 '-(1, 4-phenylene bis (oxy)) dibutyric acid, 2, 2'-( the organic solvent is at least one of 2, 2 '-(1, 4-phenylene bis (oxy)) dihexanoic acid, neodecanoic acid, 2, 2'-(1, 4-phenylene bis (oxy)) diheptanoic acid or 2, 2 '-(1, 4-phenylene bis (oxy)) dioctanoic acid. The extraction agent provided by the invention can effectively prevent an extraction system from generating emulsification or three phases, and can effectively improve the reverse extraction efficiency. In addition, the extraction agent can be designed and adjusted, the composition of the extraction agent can be adjusted according to the composition, element concentration and the like of the solution, and then efficient separation of metal elements is achieved.

The application discloses a composite sleep-aiding patch, a preparation method and application, and belongs to the technical field of sleep-aiding patches.The composite sleep-aiding patch comprises the following raw materials in percentage by weight: 0.5-1% of melatonin, 1-2% of L-theanine, 0.5-1% of 5-hydroxytryptophan, 2-3% of gamma-aminobutyric acid, 0.5-1% of linalyl acetate, 1-2% of valeric acid, 1-2% of vitamin E and 1-2% of rosmarinic acid, and the rest is auxiliary materials.The composite sleep-aiding patch can help sleep, improve the depth and quality of sleep, and has the synergistic effect of different components.

The invention relates to the technical field of chemical synthesis, in particular to a synthesis method of matrichthrin, which comprises the following steps: S1, under an alkaline condition, carrying out aldol condensation reaction on propionaldehyde to obtain a first reaction mixture containing 2-methyl-2-pentenal; s2, in the presence of a hydrogenation catalyst, 2-methyl-2-pentenal in the first reaction mixture obtained in the step S1 is subjected to a hydrogenation reaction, and a second reaction mixture containing 2-methylvaleraldehyde is obtained; s3, in the presence of an oxidation catalyst, 2-methylvaleraldehyde in the second reaction mixture obtained in the step S2 and oxygen or oxygen-containing gas are subjected to an oxidation reaction, and a third reaction mixture containing 2-methylvaleric acid is obtained; and S4, in the presence of an esterification catalyst and a water-carrying agent, carrying out esterification reaction on the 2-methylvaleric acid in the third reaction mixture obtained in the step S3 and ethanol to obtain matrichthrin. The requirement for supplementing manganese acetate is remarkably reduced, and the production cost is reduced.

The present invention belongs to the field of drug synthesis and relates to a preparation method of iloprost. Specifically, a compound of formula II is used as a raw material, and through a Wittig reaction and the splicing of a valeric acid side chain, a compound of formula III is obtained, with an E-type / Z-type ratio of about 2:1. The single E-type is obtained through liquid-phase separation, and an aldehyde, namely a compound of formula IV, is generated through Dess-Martin oxidation. Then, through a Wittig-Horner reaction and the splicing of an alkynyl side chain of a compound of formula VIII, a compound of formula V is obtained, and chiral reduction gives a compound of formula VI. Finally, the hydroxyl protecting group is removed to obtain iloprost. It has the advantages of fewer reaction steps, simple and easy process control, high total yield, and easy industrial production compared with other routes.

The present application relates to a method for detecting impurities in valproic acid or sodium valproate prepared by methyl cyanoacetate method by gas chromatography, characterized in that the impurities in valproic acid or sodium valproate prepared by methyl cyanoacetate method are detected by gas chromatography; the impurities are selected from valeric acid (A), 2-methyl valeric acid (L), 2-isopropyl valeric acid (C), valproic amide (F) or 2-propyl hexanoic acid (X):

This invention discloses a method for synthesizing α-hydroxycarboxylic acid compounds. The method includes the following steps: adding a reaction substrate, a photosensitizer, and a base to a dry reaction tube; then adding a solvent and additives under a CO2 atmosphere; and reacting under visible light irradiation. After the reaction is complete, the reaction system is acidified and quenched, and then purified to obtain the product, the α-hydroxycarboxylic acid compound. The photosensitizer includes Ir(ppy)2(dtbbpy)PF6 and 3DPA2FBN; the base is potassium tert-butoxide, cesium carbonate, or potassium tert-valerate; the additives are N,N-diisopropylethylamine and chlorosilane; and the reaction substrate is an aldehyde or ketone compound. This invention provides a highly efficient and selective synthesis of α-hydroxycarboxylic acid compounds under visible light induction and a CO2 atmosphere. The reaction conditions of this invention are mild, the reactant range is broad, the selectivity is good, and it can be scaled up to the gram scale.

The application provides a recombinant Halomonas, a construction method thereof and application of the recombinant Halomonas in production of polyhydroxyalkanoate. The recombinant Halomonas expresses 2-keto acid decarboxylase or a 2-keto acid decarboxylase mutant. The application constructs a 3HV synthesis path mediated by 2-keto acid decarboxylase, which can directly convert alpha-ketoglutarate in the tricarboxylic acid cycle into 3-hydroxyvaleryl coenzyme A, realizes de novo synthesis of 3HV monomers, can efficiently utilize conventional carbon sources to synthesize 3HV, breaks through the technical bottleneck of traditional dependence on exogenous propionic acid or valeric acid precursors, realizes obtaining of a higher proportion of 3HV under the condition of no need of adding exogenous precursors, and significantly simplifies the fermentation process and reduces raw material cost and production complexity.

The present disclosure provides a method for preparing Fmoc-Lys(Ivdde)-OH, comprising steps of: reacting dimedone with isovaleric acid in the presence of a condensing agent to obtain an intermediate compound; then reacting the intermediate compound with N-alpha-tert-butoxycarbonyl-L-Lysine in the presence of an organic base to obtain an intermediate; then reacting the intermediate with an acid to obtain another intermediate; and finally reacting the another intermediate with N-(9-fluorenylmethoxycarbonyloxy)succinimide in the presence of an inorganic base to obtain Fmoc-Lys(Ivdde)-OH. The method simplifies the process, features simple operations and mild reaction conditions, and reduces the difficulty of industrial production. Furthermore, the method does not involve expensive raw materials, which is beneficial for controlling production costs, and a product is obtained with a high purity and a high yield.

To provide more effective therapeutic agents for skin diseases, and to provide a method for easily producing 9α-fluoro-11β-hydroxy-16β-methylandrosta-1,4-diene-3,17-dione.SOLUTION: Provided are a therapeutic agent for treating skin diseases, comprising one or more compounds (a) selected from the group consisting of compounds represented by formula (I) and compounds represented by formula (II). Provided is a method for producing 9α-fluoro-11β-hydroxy-16β-methylandrosta-1,4-diene-3,17-dione, comprising contacting one or more compounds (B) selected from the group consisting of betamethasone dipropionate, clobetasol propionate, betamethasone butyrate propionate, betamethasone valerate, clobetasone butyrate, and difluprednate with NaH.SELECTED DRAWING: None

Disclosed herein are methods of electrochemical synthesis of hydroxyvaleric acid from levulinic acid. For example, disclosed herein are methods comprising electrochemical synthesis of hydroxyvaleric acid from levulinic acid, wherein the method is conducted in an electrochemical cell wherein a working electrode is in electrochemical contact with an aqueous electrolyte and levulinic acid, wherein the method comprises applying a potential to electrochemically reduce the levulinic acid to form hydroxyvaleric acid. Also disclosed herein are methods of synthesizing gamma-valerolactone from hydroxyvaleric acid, the method comprising acid-catalyzed esterification. Also disclosed herein are methods of use of the products produced by any of the methods herein.

The invention relates to the technical field of medicines, and particularly discloses a Naoxuekang dropping pill placebo as well as a preparation method and application thereof. The Naoxuekang dropping pill placebo provided by the invention is prepared from the following components in parts by weight: 7000 to 13000 parts of matrix, 100 to 600 parts of pigment and 50 to 300 parts of compound essence, the matrix is polyethylene glycol; the pigment is caramel pigment; the compound essence is prepared by mixing propionic acid, isovaleric acid, 2-methylpyrazine, p-cresol, 2, 3-dimethylpyrazine, limonene and propylene glycol. The raw and auxiliary materials used in the application are safe, non-toxic and harmless, and the prepared Naoxuekang dropping pill placebo has high consistency with a tested raw medicine sample in the aspects of pill weight, appearance, color, smell, taste and other characters, and can be clinically used as a placebo.

Rubber composition for the manufacture of a tread for a winter tire, which contains: a rubber component, (a) a zinc salt of an aliphatic C4-C 12 -carboxylic acid or (b) an aliphatic C4-C 12 -carboxylic acid and zinc oxide and an oil or a plasticizer, wherein the rubber component contains 45 mass% or more of butadiene rubber based on 100 mass% of the rubber component, wherein the amount of the zinc salt (a) and the amount of the mixture (b) are 0.2 parts by mass or more and 10 parts by mass or less, respectively, based on 100 parts by mass of the rubber component, and where in case (a), in the case of a zinc salt of an aliphatic C4-C 12 -carboxylic acid, the aliphatic C4-C 12-Carboxylic acid is a saturated fatty acid selected from the group consisting of heptanoic acid, nonanoic acid, undecanoic acid, isobutanoic acid, isopentanoic acid, pivalic acid, isohexanoic acid, isoheptic acid, isooctanoic acid, dimethyloctanoic acid, isononanoic acid, isodecanoic acid, isoundecanoic acid, isododecanoic acid, 2-ethylbutanoic acid, 2-ethylhexanoic acid, 2-butyloctanoic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and sebacic acid or an unsaturated C4-C 12 -fatty acid and where in case (b), with an aliphatic C4-C 12 -carboxylic acid and zinc oxide, the aliphatic C4-C 12-Carboxylic acid is a saturated fatty acid selected from the group consisting of butanoic acid, pentanoic acid, heptanoic acid, nonanoic acid, undecanoic acid, isobutanoic acid, isopentanoic acid, pivalic acid, isohexanoic acid, isoheptic acid, isooctanoic acid, dimethyloctanoic acid, isononanoic acid, isodecanoic acid, isoundecanoic acid, isododecanoic acid, 2-ethylbutanoic acid, 2-ethylhexanoic acid, 2-butyloctanoic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid and sebacic acid or an unsaturated C4-C 12 -fatty acid.

The invention discloses a perovskite material for improving water stability based on bidentate ligand covalent passivation and a preparation method and application thereof. The preparation method comprises the following steps: introducing a bidentate ligand of mercaptocarboxylic acid (2-11 carbons, such as mercaptoacetic acid (TGA), mercaptopropionic acid (MPA), mercaptobutyric acid (MBA), mercaptovaleric acid (MAA), mercaptohexanoic acid (MHA) and the like) into a lead iodide methyl ammonium (MAPbI3) perovskite crystal lattice, and forming a stable Pb-S covalent bond by utilizing mercapto (-SH) and Pb < 2 + >; meanwhile, carboxyl (-COOH) and methylamine ions (MA < + >) in mercaptocarboxylic acid are catalyzed through 1-ethyl-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) to form amido bonds, synchronous double-site covalent passivation of perovskite crystal lattices is achieved, and the water-stable mercaptocarboxylic acid-MAPbI3 perovskite material is formed. According to the method, decomposition of MAPbI3 in a water environment is effectively inhibited, and the water stability and the photoelectric property of the material are remarkably improved. The bidentate ligand synchronous covalent bond passivation method provided by the invention provides a new thought for improving the water stability and the photoelectric property of the perovskite material, and the prepared material has a wide application prospect in photoelectric devices such as solar cells, optical detectors and photoelectrochemical sensors, and is particularly suitable for long-term stable work in a high-humidity environment.

The invention discloses a method for preparing thioctic acid, belongs to the technical field of organic synthesis, and includes desulfurization and acidification; in the desulfurization step, in a sodium thioctic acid system containing sulfide ions, acid and a compound containing metal ions are added, filtered after reaction, and a metal chelate of thioctic acid is obtained; then the metal chelate of thioctic acid is reacted with sodium hydroxide to obtain pure sodium thioctic acid; then the pure sodium thioctic acid is acidified to obtain thioctic acid. The present invention utilizes the property that thioctic acid is easy to chelate with metal ions to form a solid, removes sulfide ions while chelating thioctic acid, greatly suppresses the generation of impurity 1,2,3-trithiocyclohexane-4-pentanoic acid, and the thioctic acid obtained by the method of the present invention has low impurity content, high purity, and high yield, and greatly improves the quality of thioctic acid.

An object of the present invention is to provide a formulation technique for improving the solubility and safety of Prednisolone Valerate Acetate in an external pharmaceutical composition containing Prednisolone Valerate Acetate.SOLUTION: An external pharmaceutical composition comprising Prednisolone Valerate Acetate and propylene glycol monocaprylate.SELECTED DRAWING: None

The invention relates to a method for detecting impurities in a process for preparing valproic acid, sodium valproate or magnesium valproate by atom economy reaction, which comprises the following steps of: selecting a gas chromatograph with the model of Agilent 8890, and detecting valproic acid prepared by atom economy reaction and process impurities thereof by gas chromatography; the detection conditions of the gas chromatography are as follows: a chromatographic column is DB-FFAP, and the specification is 0.32 mm * 60 m, 0.5 [mu] m; the carrier gas is nitrogen; the detector is an FID (Flame Ionization Detector); the flow rate is 2ml / min; the sample injection volume is 2 microliters; the temperature of a sample inlet is 220 DEG C; the column temperature is 100 DEG C; in the heating procedure, the initial temperature is 100 DEG C and kept for 5 min, then the temperature is increased to 140 DEG C at the speed of 4 DEG C / min and kept for 5 min, and then the temperature is increased to 200 DEG C at the speed of 4 DEG C / min and kept for 15 min; the operation time is 50 min; the temperature of a detector is 220 DEG C; the method comprises the following steps of: injecting 2 microliters of diluent dichloromethane, 2 microliters of reference solution and 2 microliters of test solution into a gas chromatograph, and recording a chromatogram; a test article is selected from a valproic acid crude product prepared by atom economy reaction; the impurities are selected from 2-propyl-4-pentenoic acid, valeric acid, 2-methyl valeric acid, 2-ethyl valeric acid, methyl valproate, ethyl valproate or propyl valproate; the solvent is a solvent; according to the detection result of the gas chromatography, the variety and the content of the process impurities in the valproic acid, the sodium valproate or the magnesium valproate are judged through a control sample.

The application belongs to the technical field of small molecule compound synthesis and utilization, and provides 2-amino-6-[(4-hydroxy-1-oxypentyl)amino]hexanoic acid as well as a preparation method and application thereof. The method comprises the following steps: taking gamma-valerolactone and lysine as reaction raw materials, reacting at 80-120 DEG C for 5-24 h, cooling to room temperature after the reaction is completed, performing solid-liquid centrifugal separation, and obtaining 2-amino-6-[(4-hydroxy-1-oxypentyl)amino]hexanoic acid after purifying the solid. In the application, gamma-valerolactone is both a solvent and a reactant, 2-amino-6-[(4-hydroxy-1-oxypentyl)amino]hexanoic acid is synthesized through one-step reaction, and the application has the advantages of simple preparation process, convenient operation, green and environment-friendly preparation process and the like. The prepared product can generate lysine and 4-hydroxyvaleric acid by hydrolyzing the amide group through an enzyme or alkali, and has great potential application in the fields of medicine and chemical industry.

The invention discloses a preparation method of diflucolone or diflucolone valerate, which comprises the following steps: in an inert protective atmosphere, carrying out reduction reaction on flumethasone and a reducing agent in a solvent to obtain the diflucolone, the preparation method comprises the following steps: in an inert protective atmosphere, carrying out acylation reaction on difluorocolone and an acylation reagent in a solvent in the presence of a base catalyst to obtain the difluorocolone valerate. The specific solvent is adopted in the reduction reaction, the problems that in the prior art, reaction by-products are large, raw material reaction is not thorough, the yield is low, and the production cost is high are solved, the product purity and the overall yield are obviously improved, and the production cost is reduced. According to the method, inorganic alkali and acetone are used as a solvent in the acylation reaction, the solvent can be recycled after post-treatment, the method is environment-friendly, 11-site hydroxyl is prevented from being acylated under the acylation condition, byproducts are effectively controlled, and the purity and yield of the product are improved.

The application relates to a binary ionic liquid lubricating additive and a preparation method and application thereof, the binary ionic liquid lubricating additive comprising ionic liquid I and ionic liquid II with a molar ratio of 1:1, wherein the ionic liquid I comprises cation precursor I and anion precursor I with a molar ratio of 1:1, the ionic liquid II comprises cation precursor II and anion precursor II with a molar ratio of 1:1, the cation precursor I and the cation precursor II are selected from any same one of ethanolamine, dimethylethanolamine and trioctylamine, and the anion precursor I and the anion precursor II are selected from any two different ones of valeric acid, heptanoic acid and di(2-ethylhexyl) phosphate. Compared with the prior art, the application has better anti-wear effect, and can make PAO4 base oil have excellent anti-wear property.

Disclosed herein are methods of electrochemical synthesis of hydroxyvaleric acid from levulinic acid. For example, disclosed herein are methods comprising electrochemical synthesis of hydroxyvaleric acid from levulinic acid, wherein the method is conducted in an electrochemical cell wherein a working electrode is in electrochemical contact with an aqueous electrolyte and levulinic acid, wherein the method comprises applying a potential to electrochemically reduce the levulinic acid to form hydroxyvaleric acid. Also disclosed herein are methods of synthesizing gamma-valerolactone from hydroxyvaleric acid, the method comprising acid-catalyzed esterification. Also disclosed herein are methods of use of the products produced by any of the methods herein.

Methods and consumer products for detecting a metabolite, the method comprising: testing a urine sample from a subject for a metabolite selected from the group consisting of ascorbate, dehydroascorbate, CEHC-sulfate, CEHC-taurine, CEHC-glucronide, pantoate, 5-amino valerate, galactonate, phenylacetylalanine, methylcatecholsulfate, phenylacetylglutamine, carboxysuccinate, carboxyethylvaline, arabinose, threonate, methylcrotonylglycine, glucuronate, carboxyethylisoleucine, glycoursodeoxycholate, leucylalanine, lithocholatesulfate, alio-threonine, cholic, glucuronide and combinations thereof; and producing a metabolic profile for the metabolite.

Provided is a method for preparing valproamide represented by chemical structural formula I and sodium valproate represented by formula II. The method is characterized in that cyanoacetate and 1-chlor

The invention discloses a purification and enzyme activity determination method of dihydroxy acid dehydratase, and belongs to the technical field of enzyme activity determination. According to the method for purifying the dihydroxy acid dehydratase and determining the enzyme activity, disclosed by the invention, the dihydroxy acid dehydratase obtained through in-vitro reconstruction of iron-sulfur clusters and purification can keep stable enzyme activity on the basis of a laboratory reduction method innovatively. Pyruvic acid is selected as a substrate, and generation of a catalytic precursor substance 2, 3-dihydroxy isovaleric acid of the dihydroxy acid dehydratase and synthesis of a catalytic product alpha-ketoisovaleric acid can be realized by finely designing a multi-enzyme cascade reaction; through high performance liquid chromatography analysis, an external standard method is adopted for quantification, the synthesis amount of alpha-ketoisovaleric acid is measured, and the enzyme activity is indirectly calculated. The determination method provided by the invention is simple to operate and low in operation environment requirement, and the operation cost is greatly reduced while the accuracy and the stability are considered.