41 results about "Reduced nicotinamide-adenine dinucleotide" patented technology

The invention relates to the technical field of urea detection, in particular to a preparation method of a urea determination reagent ball, the reagent ball and a detection chip. The embodiment of theinvention provides a preparation method of a urea determination reagent ball. The method comprises the following steps of mixing a certain dosage of buffer solution, disodium ethylene diamine tetraacetate, alpha-ketoglutarate, glutamate dehydrogenase, urease, reduced nicotinamide adenine dinucleotide and excipient with water to form a mixed solution, dropwise adding the mixed solution into liquidnitrogen to enable liquid drops of the mixed solution to form ice balls, and freeze-drying the ice balls to obtain spherical urea determination reagent balls. The urea determination reagent ball prepared by the method has good thermal stability, can be stored for 8 days at a high temperature of 37 DEG C, is not easy to deteriorate in the storage process, has a wide effective test range on urea inblood, and can test the highest concentration of blood urea as high as 35mmol/L.

The invention belongs to the field of pharmaceutical and chemical industry, and particularly relates to a method for continuously catalyzing and synthesizing ATS-7 by an immobilized enzyme fluidization bed. Mixed liquid of glucose and a nicotinamide adenine dinucleotide phosphate (NADP+) generates reduced nicotinamide adenine dinucleotide phosphate (NADPH) through a GDH (glutamate dehydrogenase) bed, and mixed solution of ATS-6 and generated NADPH is implemented through a CR fluidized bed, so that the ATS-7 is continuously catalyzed and synthesized by the immobilized enzyme fluidization bed. By the continuous reaction catalysis method of the immobilized enzyme fluidization bed, enzyme catalyzing efficiency is improved; enzyme utilization rate is increased, the catalytic efficiency of the immobilized enzyme is improved by 3.1-4.2 times as compared with that of traditional free enzyme, reaction processes can be controlled by independently adjusting different sample feeding flow speed, the immobilized enzyme cannot easily fall off, continuously catalyzing reaction can be achieved, the immobilized enzyme and a product are conveniently separated, the yield of the product is improved, and purification steps are simplified, and industrialization is more facilitated.

The present invention relates to a method for rapidly determining the L-glutamic acid in food. The method comprises: grinding or mincing a solid or semi-solid sample by using a suitable tool, weighing a proper amount of the grinded or minced sample, adding an appropriate solvent, homogenizing, carrying out centrifuged separation, and filtering to obtain a free L-glutamic acid extraction liquid, or carrying out protein hydrolysis to obtain the L-glutamic acid extraction liquid constituting the protein structure (the liquid sample is directly filtered without the pretreatment); properly diluting the sample extraction liquid, and adjusting the pH value to 8.6; reducing nicotinamide adenine dinucleotide (NAD<+>) into nicotinamide adenine dinucleotide (NADH) in the presence of glutamate dehydrogenase(GIDH) through the L-glutamic acid of the sample detection liquid, and carrying out a reaction on the NADH and iodonitrotrtrazolium chloride (INT) under the effect of diaphorase to generate formazan; and determining the absorption peak of the formazan at 490 nm by using a light-absorption microplate reader, and calculating the L-glutamic acid content in the sample according to the absorption value of the formazan by using an external standard method. According to the present invention, the detection method has characteristics of simple operation, good accuracy, fastness, high throughput, easy popularization, and the like.

Reusable microsomal biocatalytic systems (bioreactors) constructed on carbon nanostructure modified electrodes are provided. The bioreactors comprise stable, biologically active immobilized enzymes such as human cytochromes P 450 (CYPs) and their redox partner proteins, e.g. CYP-NADPH (reduced nicotinamide adenine dinucleotide phosphate) reductases (CPR), on the carbon nanostructure surface. The immobilized enzymes may be present in liver microsomes, such as human liver microsomes (HLM) or as bactosomes, S9 fractions, etc. The bioreactors are used, for example, for synthesizing metabolites of interest from compounds such as drugs that are catabolized by the enzymes.

The invention discloses a preparation method of a fluorescent probe for detecting reduced nicotinamide adenine dinucleotide and phosphate ester of the reduced nicotinamide adenine dinucleotide. The method includes the following steps that 7-diethylamino coumarin and 1,2,3,3-tetramethyl-6-nitro-3H-indolium iodide are added into a reactor, absolute ethyl alcohol is added after vacuum/nitrogen replacement, hot reflux stirring is carried out on 10-15 hours under nitrogen protection, the reaction liquid is concentrated and evaporated, and a target compound is obtained by purifying the obtained solid through silica gel column chromatography. According to the method, the 7-diethylamino coumarin and the 1,2,3,3-tetramethyl-6-nitro-3H-indolium iodide serve as a fluorescent matrix, and on the basisof an H selective nucleophilic addition specific cyanine derivative on NAD(P)H, a whole conjugated system is changed, so that the pushing-drawing electron capacity in molecules is influenced, and selective detection of NAD(P)H is realized by utilizing the fluorescence wavelength difference between reactants and products.

The invention discloses a synthesis method of L-galactose, which comprises the following steps: taking galactitol and oxidized nicotinamide adenine dinucleotide disodium salt, mixing, adding mannitol dehydrogenase and NADH oxidase, and reacting to generate L-galactose; or taking and mixing D-galactose and reduced nicotinamide adenine dinucleotide disodium salt, adding mannitol dehydrogenase and D-galactose reductase for a reaction, and generating L-galactose. According to the method, cheap and bulk D-galactose or galactitol in the market is adopted as a raw material, and expensive L-galactose is obtained through one-step or two-step direct conversion by utilizing an enzyme catalyst. The preparation scheme has multiple industrial application advantages, the used raw materials are cheap, the preparation route is short, the reaction conditions are simple, and the waste emission is low; and the characteristics well meet the basic requirements of current green industrial production.

The invention provides a kit for detecting D-psicose and a detection method, and relates to the technical field of detection. The kit comprises a reagent I, a reagent II, a reagent III, a reagent IV and a reagent V. The reagent I is a phosphate buffer solution, the main component of the reagent II is reduced nicotinamide adenine dinucleotide (NADH), the main component of the reagent III is ribitol dehydrogenase, and the main component of the reagent IV is D-psicose. By utilizing the kit, 96 samples can be detected within 30 minutes, and the concentration or content of D-psicose in the samples can be quickly and accurately reflected. The kit is not influenced by interferents such as D-fructose and other monosaccharides in the detection process, and can be applied to detection of the conversion amount of D-fructose to D-psicose in the KEase enzymatic reaction process and screening of KEase enzyme variants. In the detection process by using the kit, large-scale instruments and equipment are not needed, so that the detection cost can be remarkably reduced.

A label free single or multi-photon optical spectroscopy for measuring the differences between the levels of fluorophores from tryptophan, collagen, reduced nicotinamide adenine dinucleotide (NADH), and flavins exist in brain samples from a of Alzheimer's disease (AD) and in normal (N) brain samples with label-free fluorescence spectroscopy. Relative quantities of these molecules are shown by the spectral profiles of the AD and N brain samples at excitation wavelengths 266 nm, 300 nm, and 400 nm. The emission spectral profile levels of tryptophan and flavin were much higher in AD samples, while collagen emission levels were slightly lower and NADH levels were much lower in AD samples. These results yield a new optical method for detection of biochemical differences in animals and humans for Alzheimer's disease.

An object of the present disclosure is, at least, to provide an enzyme that dehydroxylates hydroxyl groups at predetermined positions of urolithins having hydroxyl groups at the predetermined positions, and the object can be solved by an enzyme having the following properties (1) and (2): (1) dehydroxylating a hydroxyl group at the 4-position of urolithins; and (2) in the presence of methyl viologen (MV), being activated by one or more components selected from the group consisting of: reduced nicotinamide adenine dinucleotide (NADH); reduced nicotinamide adenine dinucleotide phosphate (NADPH); flavin adenine dinucleotide (FAD); and flavin adenine mononucleotide (FMN).

The invention discloses a culture medium additive for improving the content of organic selenium in selenium yeast, and belongs to the technical field of selenium yeast. The culture medium additive consists of the following components: 1000 mg/L of reduced glutathione (GSH), 100 mg/L of reduced nicotinamide adenine dinucleotide tetrasodium phosphate (NADPH-Na4), 40 g/L of fructose and 400-800 mg/Lof ATP. Orthogonal experiments are carried out on the addition amounts of the four culture medium additives, and through the experiments, it finds that the selenium-enriched yeast obtained by adding the additive into the culture medium has the characteristics of high biomass, high selenium enrichment, high organic selenium conversion, high yield and the like, and the problem that the conversion amount of organic selenium in the selenium-enriched yeast is small is effectively solved.

The invention relates to the technical field of industrial catalysis, in particular to a preparation method of reduced nicotinamide adenine dinucleotide, which comprises the following steps: 1) screening the activity of formate dehydrogenase at high temperature; 2) screening the activity of formate dehydrogenase under an acidic condition; (3) according to the results of the step (1) and the step (2), formate dehydrogenase with relatively high activity under a high-temperature condition and an acidic condition is selected for later use; respectively weighing ammonium formate and NAD (Nicotinamide Adenine Dinucleotide) into a flask, adding pure water, stirring and dissolving in a water bath, and regulating the pH to be acidic by using sodium hydroxide; finally, formate dehydrogenase obtained through screening is added for reaction, sodium hydroxide is used for maintaining the pH value to be acidic, and the reduced nicotinamide adenine dinucleotide is prepared. According to the method, the reaction can be completed in a short time, so that hydrolysis of a product under an acidic condition is avoided, and carbonate generated under an alkaline condition is also avoided; after the reaction, no large amount of carbonate exists, and the purification cost is low.

The invention discloses a method for quickly evaluating an influence degree of an organic acid level for alcohol metabolism of Maotai-flavour liquor. The method comprises the following steps of: S1: preparing mixed liquor; S2: adding 5[mu]L of 0.0075mg/ [mu]L of ethyl alcohol dehydrogenase liquid into the mixed liquor, after incubation is carried out, using a spectrograph to measure a light absorption value under a condition of 340mm wavelength to obtain a [delta]A determination tube; S3: defining the activity of ethyl alcohol dehydrogenase that at the temperature of 25 DEG C, an enzyme quantity required for each 1mL of acid solution to oxidize 1[mu] mol of coenzyme I in each 1min to generate 1[mu] mol of reduced nicotinamide adenine dinucleotide is one enzyme activity unit, and a following calculation formula is obtained: ADH([mu]mol/min/mL)=[([delta]A determination tube-[delta]A empty tube)/[epsilon]/d*V reaction total volume*10<6>]/V sample adding quantity/T; and S4: according to the above formula, analyzing the activity of the ethyl alcohol dehydrogenase under different concentrations of different organic acids. Through the above formula, the method disclosed by the invention calculates the activity of the ethyl alcohol dehydrogenase under different concentrations of different categories of organic acids, the influence degree of an organic acid level for after-drinking alcohol metabolism can be evaluated.