14 results about "Dinitrofluorobenzene" patented technology

The invention discloses a fluorescent covalent organic framework material for hydrogen sulfide detection as well as a preparation method and application thereof, relates to a covalent organic framework material as well as a preparation method and application thereof, and aims to solve the technical problems that an existing porous material for H2S detection is few in structure type, unstable in COFs (Covalent Organic Frameworks) structure, high in detection limit and harsh in detection environment. The periodic structure fragment of the fluorescent covalent organic framework material for hydrogen sulfide detection is shown in the specification. 3-(5, 10-diamino-1H-phenanthrene) [9, 10-d] imidazole-2-yl) phenol and 2, 4, 6-tri (4-formylphenoxy)-1, 3, 5-triazine are subjected to a reaction to obtain a hydroxyl intermediate, the hydroxyl intermediate is modified with 2, 4-dinitrofluorobenzene, and the fluorescent material is used for qualitative detection of H2S. The method is not interfered by amino acids and anions in the environment, and is not influenced by an acid-base environment. The method can be used in the field of H2S detection.

The invention discloses a flavonol-based fluorescent probe for continuously detecting hydrogen sulfide and hypochlorous acid as well as a preparation method and application of the flavonol-based fluorescent probe. The flavonol-based fluorescent probe is 3-(2, 4-dinitrophenoxy)-7-(4-(diphenylamino) phenyl)-2-(4-(thiomorpholinophenyl) chromone, and the structural formula of the flavonol-based fluorescent probe is shown in the specification. According to the invention, 7-(4-(diphenylamino) phenyl)-3-hydroxy-2-(4-thiomorpholinophenyl) chromone is used as an initial raw material, and the 7-(4-(diphenylamino) phenyl)-3-hydroxy-2-(4-thiomorpholinophenyl) chromone and 2, 4-dinitrofluorobenzene are subjected to nucleophilic substitution reaction to obtain the compound 3-(2, 4-dinitrophenoxy)-7-(4-(diphenylamino) phenyl)-2-(4-(thiomorpholinophenyl) chromone. The compound is firstly subjected to selective thiolysis reaction under the action of hydrogen sulfide, the fluorescence color of a solution of the compound is changed from colorless to bright orange under the irradiation of ultraviolet light with the wavelength of 365 nm, then hypochlorous acid is continuously added into the solution, and the compound can be further subjected to specific oxidation reaction with the hypochlorous acid, so that the compound can be obtained. And the fluorescence color of the solution is changed from bright orange to bright cyan. Therefore, the compound can be used as a fluorescent probe for continuously detecting hydrogen sulfide and hypochlorous acid, has the advantages of low detection limit, high response speed, good light stability, wide pH application range and the like, and shows a good application prospect.

The invention relates to a method for determining the content of tobramycin in tobramycin eye drops, which comprises the following steps: 1) preparation of a reference substance solution: taking a tobramycin reference substance, and adding water and sulfuric acid to dissolve the tobramycin reference substance to prepare the reference substance solution; 2) preparation of a test solution: diluting tobramycin eye drops with water to prepare a reference solution; 3) preparation of derivatization solutions: respectively adding the reference substance solution and the test substance solution into a 2, 4-dinitrofluorophenethyl alcohol solution and a tris (hydroxymethyl) aminomethane solution for reaction, and adding acetonitrile after the reaction is completed to prepare a reference substance derivatization solution and a test substance derivatization solution; and 4) determination: taking the reference substance derivatization solution and the test sample derivatization solution, respectively injecting into a high performance liquid chromatograph to obtain chromatograms, and calculating the tobramycin content by using an external standard method according to the peak area of the chromatograms.

The present invention discloses a flavonol aromatic ether light-up type fluorescent probe for detecting hydrogen sulfide and its preparation method and application. The present invention uses 7-(4-(diphenylamino)phenyl)-2-(furan-2-yl)-3-hydroxychromone as raw material, and carries out etherification reaction with 2,4-dinitrofluorobenzene to prepare a flavonol aromatic ether light-up type fluorescent probe. The flavonol aromatic ether light-up type fluorescent probe can react with hydrogen sulfide quickly and exclusively at room temperature. Under 365nm ultraviolet light, the solution fluorescence color changes from colorless to orange-red, the minimum detection limit is 96nM, and the response time is 3min. Therefore, the flavonol aromatic ether light-up type fluorescent probe has good application prospects in detecting hydrogen sulfide.

The invention relates to the technical field of fluorescent probes, in particular to a hydrogen sulfide fluorescent probe based on naphtha coumarin and preparation and application of the hydrogen sulfide fluorescent probe based on naphtha coumarin. The preparation method of the fluorescent probe comprises the following steps: (1) carrying out a reaction on 7-hydroxycoumarin and N-phenyl bis (trifluoromethanesulfonyl) imine to obtain 7-trifluoromethanesulfonyloxy coumarin, namely a compound 4, and (2) carrying out a reaction on the compound 4 and bis (pinacol) diborate to obtain 7-pinacol borate coumarin, namely a compound 3. (3) reacting the compound 3 with 6-bromo-2-naphthol to obtain 7-(6-hydroxynaphthalene-2-yl) coumarin, namely a compound 2, and (4) reacting the compound 2 with 2, 4-dinitrofluorobenzene to obtain the hydrogen sulfide fluorescent probe 7-(6-(2, 4-dinitrophenoxy) naphthalene-2-yl) coumarin based on naphtha coumarin, namely a compound 1. According to the application of the fluorescent probe, whether hydrogen sulfide exists or not is detected by utilizing the change of fluorescence intensity at 505 nm. The preparation and treatment process of the fluorescent probe is simple, and the fluorescent probe has the advantages of being good in selectivity, high in sensitivity, high in response speed and the like in a hydrogen sulfide and other interferent coexisting system.

The invention belongs to the technical field of oilfield chemistry, and particularly relates to a corrosion inhibition polymer for acid fracturing, a corrosion inhibitor composition and a preparation method of the corrosion inhibition polymer. The preparation method of the corrosion inhibition polymer for acidizing and fracturing comprises the following steps: taking N-carbobenzoxy histidine and N-carbobenzoxy tryptophan, respectively protecting the N-carbobenzoxy histidine and the N-carbobenzoxy tryptophan by using 2, 4-dinitrofluorobenzene, obtaining corresponding acid anhydrides with protecting groups by using thionyl chloride, polymerizing the acid anhydrides, and removing the protecting groups to obtain the corrosion inhibition polymer. The preparation method of the corrosion inhibitor composition comprises the step of compounding the corrosion inhibition polymer and iodized salt. The corrosion inhibitor compound is a polypeptide polymer formed by histidine and tryptophan, is compounded with iodized salt, can form effective covering on the metal surface, meets the corrosion inhibition requirement under the acid fracturing condition, and belongs to an environment-friendly reagent.

The invention relates to a method for detecting gamma-aminobutyric acid of fermented soybean by precolumn derivatization, which comprises the following steps: preparing a phosphate buffer solution: preparing a solution A: weighing 1.56 g of sodium dihydrogen phosphate, putting the sodium dihydrogen phosphate into a 50mL volumetric flask, adding ultrapure water, and fixing the volume to 50ml; 7.20 g of disodium hydrogen phosphate is weighed and put into a 100 mL volumetric flask, ultrapure water is added, and the volume is fixed to 100 mL; mixing: weighing a proper amount of the solution A and the solution B, adjusting the pH to 7.2, and taking 100mL of the mixed solution for later use; preparing 0.5 mol / L sodium bicarbonate: weighing 0.6 g of anhydrous sodium carbonate and 3.7 g of sodium bicarbonate, putting the anhydrous sodium carbonate and the sodium bicarbonate into a 100 mL volumetric flask, then adding ultrapure water, and fixing the volume to 100 mL; preparing a 1% FDNB acetonitrile deriving agent: weighing 0.5 g of FDNB, putting the FDNB into a 50mL volumetric flask, adding acetonitrile, and fixing the volume to 50ml; 3 g of fermented soybean powder is weighed, 50 mL of ultrapure water is added, ultrasonic extraction is carried out for 40 min, centrifugation is carried out, and supernate is taken as the sample solution. According to the method, the gamma-aminobutyric acid of the fermented soybean is detected by taking the fermented soybean as an object, and a 2, 4-dinitrofluorobenzene pre-column derivatization HPLC (High Performance Liquid Chromatography) method is optimized and established.

The present invention discloses a method for high-throughput screening of leucine dehydrogenase and a leucine dehydrogenase. Using the method of the present invention, protein engineering modification is carried out on leucine dehydrogenase BtLDH, and a high-throughput screening method is used to culture recombinant strains and strain mutants containing leucine dehydrogenase BtLDH in 96-well plates, and subculture induction is carried out. Cells containing leucine dehydrogenase BtLDH of Bacillus thuringiensis are centrifuged and collected to transform 2-ketobutyric acid to produce L-2-aminobutyric acid, and after color development with 2,4-dinitrofluorobenzene (DNFB), the absorbance value is read at 500 nm, and the strains with large absorbance values are verified in shake flasks. Each leucine dehydrogenase is successfully screened within a short time. Among them, the optimal mutant A262S produces 9.22 g / L of L-2-aminobutyric acid, and the yield of L-2-aminobutyric acid is increased by 3.04 g / L compared with the wild type.

The present invention relates to the field of pharmaceutical and chemical analysis and detection technology, and mainly to an analytical method for the chiral purity of an amino acid and its derivatives, which adopts pre-column derivatization-reverse-phase high performance liquid chromatography for analysis and determination, which mainly includes using 2,4-dinitrofluorobenzene for pre-column derivatization. The technical solution of the present invention is simple and easy to operate, easier to standardize operation, and more suitable for industrial application. In addition, the derivatization reaction conditions of the technical solution of the present invention are mild and rapid, and the analytical method has a stable baseline, high sensitivity, good repeatability, and a separation degree of up to 4.2 during system operation, and the test results are accurate and effective, providing reliable information for product research and development, production and purification, and laying a solid foundation for establishing quality control standards for amino acids and their derivatives.

This invention discloses a 2-hydroxy-3-pinene-difluoroborane complex-based fluorescent probe for detecting H2S, its preparation method, and its application. The invention uses 2-hydroxy-3-pinene as a raw material and reacts it with 6-hydroxy-2-naphthaldehyde via an aldol condensation reaction to obtain compound DQ; compound DQ undergoes a complexation reaction with boron trifluoride-diethyl ether to obtain compound DQTY; compound DQTY undergoes a substitution reaction with 2,4-dinitrofluorobenzene to obtain the fluorescent probe DQTY-HS. Probe DQTY-HS specifically recognizes H2S. Upon addition of H2S to a DMSO / PBS (1:9, v / v) solution of DQTY-HS, the fluorescence color of the solution changes from colorless to yellow under 365 nm ultraviolet light irradiation, with a response time of 30 s and a detection limit of 50 nM. This probe has many advantages, such as simple synthesis, good selectivity, high sensitivity, good biocompatibility, and low toxicity, and has good application prospects in environmental analysis and food fields.

The present invention relates to the technical field of new drug indications, and specifically discloses an external use preparation of bletilla striata polysaccharide for preventing and treating eczema and pruritus, its preparation method and application. The present invention proves through scientific experiments that the external use preparation of bletilla striata polysaccharide can promote the rapid regression of acute and chronic eczema symptoms induced by dinitrofluorobenzene (DNFB) in rats within a short period of time, and its prevention and treatment effect is significantly better than the commonly used control drugs in clinical practice of traditional Chinese and Western medicine (compound phellodendron liquid, Binghuang Fule ointment, compound dexamethasone acetate cream), and can also rapidly inhibit the pruritus signs in mice induced by the combined use of histamine and 4-aminopyridine, and its prevention and treatment effect is also close to the commonly used control drugs in clinical practice of traditional Chinese and Western medicine (Qingpeng ointment, compound dexamethasone acetate cream).

The present invention belongs to the field of microorganisms, and specifically relates to an anti-allergic Kluyveromyces marxianus, a bacterial agent, and its preparation and application. The Kluyveromyces marxianus is Kluyveromyces marxianus ( Kluyveromyces marxianus ) 31691, which is deposited in the China Center for Type Culture Collection (CCTCC) with a deposit number of CCTCC NO: M 20241589. The Kluyveromyces marxianus 31691 provided by the present invention has an inhibitory effect on hyaluronidase activity. The Kluyveromyces marxianus 31691 of the present invention reduces the type I allergic reaction induced by bovine milk β-lactoglobulin, reduces the level of serum-specific IgE antibodies, helps to restore ileal villus damage and improve the depth of ileal crypts. At the same time, it is also proved that the Kluyveromyces marxianus 31691 of the present invention improves the characteristics of spleen corpuscles, regulates the body's immune function, and has an improving effect on type IV allergic reactions induced by p-dinitrofluorobenzene, and can effectively relieve allergic symptoms.

The invention discloses a colorimetric-fluorescent dual-channel near-infrared probe for H2S specific detection, and a preparation method and application thereof, and belongs to the field of chemical analysis and detection. The preparation method comprises the following steps: firstly, preparing a compound 1 by taking anhydrous N, N-dimethylformamide, dichloromethane, phosphorus tribromide and cyclohexanone as reaction raw materials; reacting the compound 1, cesium carbonate and 2-hydroxy-4-methoxybenzaldehyde to prepare a compound 2; secondly, dropwise adding boron tribromide into a dichloromethane solution in which the compound 2 is dissolved, and reacting to obtain a compound 3; the preparation method comprises the following steps: enabling 3-hydroxy-3-methyl-2-butanone, malononitrile and sodium ethoxide to react to obtain TCF; thirdly, the compound 3 and TCF are subjected to a dissolution reaction, and TEC-OH is obtained; and finally, dropwise adding a dichloromethane solution containing 2, 4-dinitrofluorobenzene into a dichloromethane solution containing TEC-OH and triethylamine, and reacting to obtain the probe TEC-H2S. The colorimetric-fluorescent near-infrared probe TEC-H2S is successfully designed and synthesized on the basis of an intramolecular charge transfer (ICT) mechanism and is used for specific detection of H2S, and a sensing technology with a great application prospect is provided for H2S detection.

The invention belongs to the field of microorganisms, and particularly relates to anti-allergic kluyveromyces marxianus, a microbial agent and preparation and application of the anti-allergic kluyveromyces marxianus. The Kluyveromyces marxianus is Kluyveromyces marxianus 31691, the Kluyveromyces marxianus is preserved in the China Center for Type Culture Collection (CCTCC), and the preservation number of the Kluyveromyces marxianus is CCTCC NO: M 20241589. The Kluyveromyces marxianus 31691 provided by the invention has an inhibition effect on the activity of hyaluronidase. According to the Kluyveromyces marxianus 31691 disclosed by the invention, cow milk beta-lactoglobulin induced type I anaphylactic reaction is reduced, the serum specific IgE antibody level is reduced, and the Kluyveromyces marxianus 31691 is favorable for recovering intestinal villus damage and improving the ileum crypt depth. Meanwhile, the kluyveromyces marxianus 31691 disclosed by the invention is also proved to improve the characteristics of the spleen small body, regulate the immune function of the body, have an improvement effect on IV-type anaphylaxis induced by p-dinitrofluorobenzene, and can effectively relieve the anaphylaxis symptom.