32 results about "Carbamic acid ethyl ester" patented technology

A modified release pharmaceutical formulation includes about 30-70% N-(2-amino-4-(fluorobenzylamino)-phenyl)carbamic acid ethyl ester (retigabine), or a pharmaceutically acceptable salt, solvate or hydrate thereof, about 5-30% of a drug delivery matrix including hydroxypropylmethylcellulose (HPMC), and an enteric polymer. The pharmaceutical formulation produces a sustained plasma concentration of retigabine following administration to a subject for 4-20 hours longer than the time required for in vitro release of 80% of retigabine. The plasma concentration vs. time profile of this formulation is substantially flat over an extended period lasting for about 4 hours to about 36 hours. A method of treating a disorder characterized by nervous system hyperexcitability includes administering to a subject an effective amount of these pharmaceutical formulations.

A modified release pharmaceutical formulation includes about 30-70% N-(2-amino-4-(fluorobenzylamino)-phenyl)carbamic acid ethyl ester (retigabine), or a pharmaceutically acceptable salt, solvate or hydrate thereof, about 5-30% of a drug delivery matrix including hydroxypropylmethylcellulose (HPMC), about 1.0-10% of an anionic surfactant, and an enteric polymer. The pharmaceutical formulation produces a sustained plasma concentration of retigabine following administration to a subject for 4-20 hours longer than the time required for in vitro release of 80% of retigabine. A formulation includes about 30-70% N-(2-amino-4-(fluorobenzylamino)-phenyl)carbamic acid ethyl ester (retigabine), or a pharmaceutically acceptable salt, solvate or hydrate thereof, about 5-30% of a drug delivery matrix, and an agent for retarding release in the gastric environment. The plasma concentration vs. time profile of this formulation is substantially flat over an extended period lasting for about 4 hours to about 36 hours. A method of treating a disorder characterized by nervous system hyperexcitability includes administering to a subject an effective amount of these pharmaceutical formulations.

The invention discloses a method for rapidly simultaneously detecting eight sweeteners and urethane in baijiu by UPLC serially connecting QDa. The method comprises the steps of pre-treating a baijiu sample to be tested, separating by ultra-high performance liquid chromatography, and carrying out data acquisition and detection with dual channels of a QDa detector. The method is simple, rapid, accurate and reliable, and can be used for simultaneously detecting the content of 8 sweeteners (acesulfame, sodium saccharin, cyclamate, aspartame, neotame, rebaudioside A, stevioside, and sucralose) andurethane in baijiu.

The invention discloses ethyl carbamate hydrolytic enzyme mutants capable of improving the thermostability, and belongs to the technical field of gene engineering and enzyme engineering. By means of a molecular technical means, the ethyl carbamate hydrolytic enzyme mutants capable of improving the thermostability are obtained, and the half-life periods of the ethyl carbamate hydrolytic enzyme mutants Q328C and Q328V are increased by 7.46 times and 1.96 times respectively compared with a native enzyme. The mutants Q328C, Q328R and Q328 V all have better tolerance at 30 DEG C or above than the native enzyme. In addition, the tolerance to ethyl alcohol and the tolerance to acid of the mutant Q328C are improved.

The invention discloses an ethyl carbamate hydrolase mutant and application thereof. The ethyl carbamate hydrolase mutant is obtained by mutation of an amidase gene of Agrobacterium tumefaciens d3, the amino acid sequence of wild amidase is shown as SEQ ID No.1, and the ethyl carbamate hydrolase mutant is obtained by mutation of at least one site of R94P, I97L, S177C or G195A of the wild amidase.The amidase from the Agrobacterium tumefaciens d3 is obtained by screening, the residual enzyme activity is higher than 90% when the ethanol concentration is between 0% and 20%, the enzyme activity isquickly reduced when the ethanol concentration is higher than 25% , and the amidase shows excellent tolerance to low-concentration ethanol. Through semi-rational transformation, a mutant library with21 point mutations is constructed, four mutation sites (R94P, I97L, S177C and G195A) with improved enzyme activity are screened from the mutant library, and the enzyme activity of a combined mutant strain I97L/G195A is improved by 5.2 times and is improved to 2442U/L from original 395U/L.

A high-purity 3-isocyanatopropyltriethoxysilane synthesis device and a synthesis method thereof belong to the field of chemical synthesis. The synthesis method of the present invention comprises the following steps: heating the fixed-bed reactor to 350° C. to 400° C. and maintaining the temperature for use; adjusting the pressure reducing valve to pass protective gas into the fixed-bed reactor, and after passing the protective gas for 3 to 30 minutes, The raw material [3-(triethoxysilyl) propyl] ethyl carbamate is passed into the fixed-bed reactor by a metering pump for a thermal cracking reaction, and the reaction time is 2 to 4 hours; the mixture after the reaction in step 2 passes through the first The condenser is cooled, and the first condenser is cooled with 80°C hot water. The cooled mixture enters the gas-liquid separator for separation, and the separated liquid enters the product receiving tank through the cooler. The invention obtains 97.5 g of high-purity 3-isocyanatopropyl triethoxysilane with a yield of 81.3 percent and a gas chromatography detection purity of 99.19 percent. The production process is safer, the process is simpler, the product is easy to separate, and the reaction raw materials are completely converted.

The invention provides a preparation method for a nanofiber membrane used for detecting ethyl carbamate. The preparation method comprises the steps that spinning materials are dissolved in solvent andmixed uniformly to obtain a spinning solution; acetylcholin esterase and a phosphate buffer are mixed to prepare an enzymic preparation; parts of spinning solution and the enzymic preparation are mixed according to the volume ratio that the spinning solution volume to the enzymic preparation volume is (1-2):1, and a spinning solution A is obtained; another parts of spinning solution and a color developing agent are mixed according to the volume ratio that the spinning solution volume to the color developing agent volume is (2-3):1, and a spinning solution B is obtained; the spinning solutionA and the spinning solution B are subjected to electrostatic spinning to obtain the nanofiber membrane. When the nanofiber membrane is utilized to detect ethyl carbamate, the contact area between theethyl carbamate and nanofibers is larger, so that the ethyl carbamate, the color developing agent and the enzymic preparation take effect, thereby generating a color developing result, and the color developing result is utilized to quickly and accurately judge the ethyl carbamate content in a sample.

The invention discloses a preparation method and application of an electrochemical immunosensor based on enzyme induction. The preparation method comprises the following steps of: (1) cleaning a glassy carbon electrode; and (2) constructing a probe; The construction of the probe specifically comprises the following steps of: dropwise adding an ethyl carbamate coating antigen (Ag) to the glassy carbon electrode for incubation; soaking the glassy carbon electrode in a BSA solution; soaking the glassy carbon electrode in an ethyl carbamate indirect rabbit polyclonal antibody (Ab1) for incubation;and finally, soaking the glassy carbon electrode in mouse polyclonal antibody-alkaline phosphatase (Ab2-ALP) for incubation. With the preparation method of the invention adopted, a competitive electrochemical immunosensor based on basic phosphatase (ALP) induced Cu <2+>/Cu<+> conversion is developed. The competitive electrochemical immunosensor can be used for sensitively detecting ethyl carbamate. Compared with the detection sensitivity of a traditional enzyme-linked immunosorbent assay, the detection sensitivity of the competitive electrochemical immunosensor is improved through three rounds of signal amplification, namely catalytic reaction of ALP enzyme, Cu<2+>/Cu<+> conversion and square wave voltammetry signal output.

The invention relates to a camptothecin 20-site modified sulfonylurea compound shown as a formula (I), a preparation method of the compound, and application of the compound in preparation of antitumordrugs. The chemical general formula of the compound is shown as a structural formula (I). The preparation method of the compound in the formula (I) is characterized in that different 20-amino acid-camptothecin trifluoroacetate reacts with different substituted sulfonyl ethyl carbamate to obtain the compound. Cytotoxic activity test proves that the compounds have good cytotoxic activity, the antitumor activity of most of the compounds is higher than that of a clinical control drug irinotecan, the antitumor activity of part of the compounds is equivalent to that of a clinical control drug topotecan, and the compounds can be used for preparing antitumor drugs. The preparation method is simple, raw materials are cheap and easy to obtain, and product purity is high.

The invention relates to novel multicomponent crystals, to the production thereof, and to the use thereof for treating pain conditions, in particular of unclear genesis, by means of a simultaneous effect on pains which are caused by muscle tension or degenerative joint diseases as well as on pains that are based on inflammatory processes. The novel multicomponent crystals contain ([2-amino-6-(4-fluoro-benzylamino)-pyridin-3-yl]-carbamic acid ethyl ester (flupirtine) and 2-[2-[(2,6-dichlorphenyl)-amino]-phenyl]-acetic acid (diclofenac) as the sole active ingredient combination and can be produced by dissolving the two components in a molar ratio of 1.0:0.9 to 1.0:1.1 in an inert organic solvent and subsequently crystallizing the complex compound.

A modified release pharmaceutical formulation includes about 30-70% N-(2-amino-4-(fluorobenzylamino)-phenyl) carbamic acid ethyl ester (retigabine), or a pharmaceutically acceptable salt, solvate or hydrate thereof, about 5-30% of a drug delivery matrix including hydroxypropylmethylcellulose (HPMC), and an enteric polymer. The pharmaceutical formulation produces a sustained plasma concentration of retigabine following administration to a subject for 4-20 hours longer than the time required for in vitro release of 80% of retigabine. The plasma concentration vs. time profile of this formulation is substantially flat over an extended period lasting for about 4 hours to about 36 hours. A method of treating a disorder characterized by nervous system hyperexcitability includes administering to a subject an effective amount of these pharmaceutical formulations.

The invention discloses a method for synthesizing ethyl N-methyl cyanocarbamate by using a methylation reagent. The method comprises the following steps of: 1) reacting cyanamide with ethyl chloroformate under a strong alkali condition to generate ethyl cyanocarbamate; and 2) carrying out reaction on ethyl cyanocarbamate and a methylation reagent dimethyl carbonate under a strong alkaline condition to generate ethyl N-methyl cyanocarbamate. According to the new method for synthesizing the ethyl N-methyl cyanocarbamate by using the methylation reagent, the low-toxicity and safe methylation reagent dimethyl carbonate is used for replacing dimethyl sulfate; the method is safer, can overcome the problem of equipment corrosion caused by acid regurgitation of wastewater in the conventional method, and has the advantages of more stable reaction, few byproducts, higher yield and stronger operability.

Disclosed is an oligo-acid fertilizer liquid and its preparation method, where the constituents include organelle 0.2-0.5%, ethyl carbamate 0.2-1%, amino acid 1-10%, fulvic acid 2-10%, carbamide 5-15%, potassium dihydeogenorthophosphate 6-18%, magnesium sulfate 8-35%, boracic acid 5-15%, zinc sulfate 8-24%, ammonium molybdate 0.2-1%, copper sulfate 4-12%, manganese sulfate 4-12%, selenium 1-3%, chromium 1-3%, EDTA 0.3-1%, and acetic acid 0.2-1%.

The invention provides a method and a device for separating, refining and purifying an intermediate ethyl m-xylylene dicarbamate solution and application of the intermediate ethyl m-xylylene dicarbamate solution. The method comprises the following steps: sequentially carrying out flash evaporation, first rectification and second rectification on an XDC solution, carrying out first-stage washing, first-stage oil-water separation, first-stage evaporation, second-stage evaporation, second-stage washing, second-stage oil-water separation and dehydration treatment to obtain refined and purified XDC; according to the method, a series of separation processes are designed according to the properties of the XDC and impurities contained in the solution, so that the separation, refining and purification of the XDC can be safely and stably realized, the impurities in the XDC solution are thoroughly removed, the residual quantity of impurity ions and metal oxides in the product is less than 10ppm, and the product quality is improved; the method can also efficiently recover the carbonylation agent and the solvent for cyclic utilization, has certain economical efficiency, and is beneficial to industrial application.