6 results about "Cefotaxime" patented technology

This invention provides a polypeptide comprising the sequence shown in any one of SEQ ID NO:1-8. It also provides a composition comprising the polypeptide with the sequence shown in SEQ ID NO:7, cefotaxime, and sulbactam. The polypeptide with the sequence SEQ ID NO:7 exhibits strong inhibitory activity against *Escherichia coli* or *Listeria monocytogenes*. When used in combination with cefotaxime and sulbactam, this polypeptide exhibits strong inhibitory activity against β-lactamase-producing *Escherichia coli*. Therefore, the polypeptide and composition have significant clinical value.

The application belongs to the technical field of biological medicine, and specifically provides a cefotaxime acid and a continuous preparation method thereof. The method comprises the following steps: firstly, mixing 7-ACA suspension liquid with triethylamine solution; then, condensing the mixture with AE-active ester solution; then, extracting and separating the condensate liquid twice through an extraction separation device and methylene chloride back extraction to obtain an aqueous phase; reacting the aqueous phase with hydrochloric acid to obtain cefotaxime acid crystallization liquid; finally, taking part of the cefotaxime acid crystallization liquid to prepare seed crystal mixture liquid, adding the remaining cefotaxime acid crystallization liquid and crystallization solvent into the seed crystal mixture liquid at a specific speed to obtain cefotaxime acid. The method realizes continuous preparation of cefotaxime acid, significantly shortens the preparation period, improves the production efficiency, reduces the side reaction and product degradation, lays a foundation for preparing high-quality cefotaxime acid, and is beneficial to industrial production.

The invention relates to the technical field of cefotaxime acid impurity control, and particularly discloses a method for controlling genotoxic impurities in cefotaxime acid. Carrying out water quenching and organic solvent extraction on reaction liquid obtained after the reaction of the 7-ACA and the AE active ester, and adjusting the pH value of the obtained water-phase feed liquid to be less than or equal to 7; and then adding a sulfur-loaded adsorbent for adsorption, carrying out solid-liquid separation, and crystallizing the obtained filtrate under an acidic condition to obtain the cefotaxime acid. According to the method provided by the invention, the existing cefotaxime acid synthesis step and crystallization step do not need to be specially set, and the content of 2-mercaptobenzothiazole in the cefotaxime acid product can be ensured to be below 3.0 ppm only by ensuring that the feed liquid before adsorption is an acidic aqueous phase solution and the content of 2-mercaptobenzothiazole in the feed liquid is below 0.5%. The method can be suitable for various cefotaxime acid synthesis processes with a water phase extraction step, is wide in application range, and can realize industrial production.

The present application belongs to the technical field of complex enzyme. The present application provides a beta-lactamase complex enzyme capable of degrading various antibiotics, and a fixing method and application thereof. The preparation method of the complex enzyme comprises the following steps: extracting gene fragments of CTX-M type broad-spectrum beta-lactamase and VIM type metal-beta-lactamase from Klebsiella pneumoniae; obtaining the target gene fragments through PCR amplification, and constructing into a basic vector to obtain a recombinant vector; transforming the recombinant vector into host cells for heterologous expression; and through protein induction, SDS-PAGE protein gel electrophoresis and protein purification, the complex enzyme is obtained. The complex enzyme successfully degrades penicillins such as ampicillin, carbapenems such as imipenem, cephalosporins such as cefotaxime and other beta-lactams. The complex enzyme gene is successfully expressed in Escherichia coli, and the optimal fixing condition is obtained. The beta-lactamase complex enzyme is fixed under the optimal fixing condition, and can be repeatedly used.

The application discloses a beta-lactamase and a gene for coding the beta-lactamase, and further discloses an expression cassette, a recombinant carrier, a recombinant cell or a recombinant bacteria, and a construction method of the recombinant bacteria, and further discloses the application of the beta-lactamase, the gene for coding the beta-lactamase, the expression cassette, the recombinant carrier, the recombinant cell or the recombinant bacteria, and the construction method of the recombinant bacteria in removing beta-lactam antibiotic pollution in the environment. The beta-lactamase gene is transformed into escherichia coli, so that the escherichia coli can hydrolyze beta-lactam antibiotics in the environment, including ampicillin, cefazolin, cefotaxime, imipenem and amikacin, and has great application value in eliminating beta-lactam antibiotic pollution in the environment.

This invention provides the application of norzelamin in the preparation of NDM-1 enzyme inhibitors. Through cefotaxime hydrolysis assays, checkerboard minimum inhibitory concentration (MIC) tests, growth curves, bactericidal curves, hemolysis tests, and *Gnaphalium affine* infection experiments, it was demonstrated that norzelamin can inhibit NDM-1 enzyme activity and exhibits good synergistic antibacterial activity with the carbapenem antibiotic meropenem, enhancing the protective effect of meropenem against *Gnaphalium affine* larval infection models. Therefore, norzelamin, as a potential adjuvant for β-lactam antibiotics, can enhance the antibacterial effect of β-lactam antibiotics by inhibiting NDM-1 enzyme activity, which is of great significance for the clinical development of safe and effective β-lactam antibiotic adjuvants.