10 results about "Methylumbelliferone" patented technology

The invention relates to the technical field of culture media, and particularly discloses a candida chromogenic culture medium as well as a preparation method and application thereof. The candida chromogenic culture medium disclosed by the invention is prepared from the following components in concentration: 10 to 11 g / L of peptone, 12 to 17 g / L of agar, 7 to 9 g / L of glucose, 1 to 2 g / L of chromogenic substrate and 0.4 to 0.6 g / L of bacteriostatic agent, the chromogenic substrate is formed by mixing heavy 4-nitrophenyl-N-acetyl-beta-D-galactosamine and 4-methylumbelliferone-beta-D-N-acetyl galactosamine, and the chromogenic substrate is formed by mixing heavy 4-nitrophenyl-N-acetyl-beta-D- The bacteriostatic agent is prepared by mixing chloramphenicol, taurocholic acid and nalidixic acid. When being used for detecting and identifying candida albicans, candida tropicalis, candida krusei and candida glabrata, the chromogenic culture medium provided by the invention has strong specificity, short identification time and wide practical application value.

The invention belongs to the field of medicines, and discloses a pharmaceutical composition for inhibiting the growth of cisplatin-resistant tumors, which comprises a TGFR2 inhibitor, a PD-1 antibody and auxiliary components, and the auxiliary components are 2-amino-2-norbornic acid and / or 4-methylumbelliferone. The composition can effectively relieve the growth of the positive drug-resistant tumor of the Pars2 caused by cis-platinum, and experiments prove that the TGFR2 inhibitor, the PD-1 antibody and the auxiliary components have obvious synergy. In addition, the invention also discloses application of the composition.

The present disclosure provides compositions, methods, and kits for detecting lipolytic activity. In some embodiments, the composition comprises an aqueous assay sample and an organic solvent, wherein the organic solvent comprises 4-methylumbelliferyl oleate (4MuO). Also provided herein are methods for determining the stability of a protein preparation.

The invention provides a probe, a kit and a detection method for detecting salmonella, and belongs to the technical field of pathogenic bacterium detection. The research provides an unmarked fluorescent biosensing platform for high-sensitivity detection of salmonella. A target sequence is introduced into a catalytic core sequence of Aurora DNAzyme, so that a signal probe E-Aurora is constructed. The E-Aurora can be combined with a substrate 4-methylumbelliferone phosphate disodium salt to generate a strong fluorescent compound 4-MU. When salmonella exists, PfAgo is activated and specifically cuts the E-Aurora probe, so that the structural integrity of E-Aurora is destroyed and the catalytic ability of E-Aurora is lost, and the generation of a fluorescence signal is hindered. The biosensor realizes ultra-high sensitivity detection of salmonella, the limit of detection (LOD) is as low as 1 CFU / mL, and an ideal recovery rate (80-120%) is obtained in actual sample detection. The detection method disclosed by the invention is simple to operate and wide in application range, and can be used for determining trace salmonella in food.

Provided is a method for sequential determination of microorganisms that express enzyme activities having different pH optima. The determination is performed on a single sample which is sequentially subjected to one or more enzyme substrates for these enzyme activities, where the substrates release methylumbelliferone derivatives as a result of the enzyme activity and where the substrates are contacted with the sample at an initial pH followed by a different higher or lower pH. As a result, a measurement of the conversion of substrate at the first pH value and a measurement of the total conversion is used to provide for conversion rates in total and at the different pH values. In turn, these conversion rates are used to calculate microorganism number or concentration. Also provided is a kit or apparatus for implementing the method.

The invention relates to the technical field of food biochemistry and lipase detection, in particular to an in-situ screening and identification method of high-activity rice bran endogenous lipase and application of the in-situ screening and identification method. Comprising the following steps: carrying out electrophoretic separation on rice bran protein, incubating separated gel in a solution containing a 4-methylumbelliferone fatty acid ester substrate, and carrying out in-situ identification on a lipase strip in a protein mixture by detecting a fluorescence signal. According to the method, the cross-modal luminescence characteristic of 4-methylumbelliferone in a nucleic acid imaging environment is utilized, and the LC-MS / MS technical means is combined, so that the sequence information of enzyme is retrieved and determined through a bioinformatics database, and the identity attribution of representative lipase in rice bran is defined. The method has the characteristics of rapidness and sensitivity, and lays a foundation for explaining a mechanism of rice bran rancidity caused by rice bran lipase and excavating high-activity lipase.

The invention relates to the technical field of resin material processing, and discloses a transparent heat-resistant PET material and a preparation method thereof.The preparation method comprises the following steps that 1, PET-1 and an additive are dissolved in a solvent system, and a first intermediate is obtained through a reaction; (2) blending, extruding and granulating the first intermediate, PET-2 (Polyethylene Terephthalate) and PETG (Polyethylene Terephthalate Glycol) to obtain a second intermediate; (3) blending, extruding and granulating the second intermediate, PAR and a chain extender to obtain a PET material; the additive is prepared from at least one of 4-methyl umbelliferone-beta-D-xyloside, 5-methoxy-9-oxo-9, 10-dihydroacridine-4-carboxylic acid and 5-hydroxy-9-oxo-9, 10-dihydroacridine-4-carboxylic acid, and the additive is prepared from at least one of 4-methyl umbelliferone-beta-D-xyloside, 5-methoxy-9-oxo-9, 10-dihydroacridine-4-carboxylic acid and 5-hydroxy-9-oxo-9 According to the method, the PET master batch is modified through the additive, the density of a benzene ring and a pyranoid ring in a molecule is increased, the rigidity of a molecular chain is further improved through the structural characteristic of 9, 10-dihydroacridine, the heat resistance of a base material is improved, the transparency of the material is improved, and meanwhile good processing performance and excellent mechanical performance are achieved.

The application discloses application of glycoside compounds in prevention and treatment of plant pathogenic viruses and belongs to the technical field of pesticide antiviral agents.Taking a tobacco mosaic virus coat protein as an example, small molecules including sugar rings, such as Swertiamarin I (A0) and ZINC85593196 (B0), are screened through virtual screening, molecular dynamics simulation, molecular mechanics and MM / GBSA free energy calculation. Based on this, further optimization is carried out, and six compounds similar to the structure of A0, such as 4-methylumbelliferone-beta-D-xyloside (A1), gardenoside (A2), 4-methylumbelliferone-beta-D-pyranoside (A3), 4-methylumbelliferone-beta-D-pyranoglucoside (A4), catalpol (A5) and esculin (hemihydrate) (A6), are obtained, and in-vivo and in-vitro biological activity evaluation is carried out. The active ingredients screened by the above method have good inhibitory effect on plant viruses.

The invention relates to a method for determining α-arabinofuranosidase (ABF) activity in a sample, referred to as the sample to be analyzed (p), of a product intended for animal feed and containing an additive having α-arabinofuranosidase activity, said α-arabinofuranosidase activity to be determined being specific to said additive, said method comprising the following steps: a sample, referred to as the control sample (c), of said product free from said additive is available on the one hand, and said sample to be analyzed (p) is available on the other hand; for each of said control (c) and sample to be analyzed (p), respectively, an enzymatic fraction having α-arabinofuranosidase activity is extracted under the same conditions, then the α-arabinofuranosidase activity of each of the extracts, respectively ABFc and ABFp, is measured; and ABFp – ABFc is calculated to obtain said ABF activity specific to said additive in said product;according to which method, α-arabinofuranosidase activity is measured by fluorescence using an enzymatic substrate, 4-methylumbelliferyl-α-L-arabinofuranoside (4-MU-ABF), which is hydrolyzable into fluorescent 4-methylumbelliferone (4-MU).

The invention relates to a method for determining α-arabinofuranosidase (abbreviated ABF) activity in a sample, referred to as the sample to be analyzed (p), of a product intended for animal feed and containing an additive that exhibits ABF activity, the ABF activity to be determined being specific to the additive, the method comprising the following steps: on the one hand, a sample, referred to as the control sample (c), of the product which is free of the additive, and, on the other hand, the sample to be analyzed (p), are provided; for each of the control sample (c) and the sample to be analyzed (p), respectively, an enzyme fraction exhibiting ABF activity is extracted under the same conditions, then the ABF activity of each of the extracts, respectively ABFc and ABFp, is measured; and ABFp - ABFc is calculated to obtain the specific ABF activity of the additive in the product; according to which method the ABF activity is measured by fluorescence by means of a substrate for the enzyme, 4-methylumbelliferyl-α-L-arabinofuranoside, which is hydrolyzable to fluorescent 4-methylumbelliferone.