39684-61-2Relevant academic research and scientific papers
Method for synthesizing (Z)-2-(alpha-methoxyimino)furanylacetic acid ammonium
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Paragraph 0026; 0027; 0028; 0029, (2016/11/07)
The invention belongs to the technical field of medical intermediate preparation, and particularly relates to a method for synthesizing (Z)-2-(alpha-methoxyimino)furanylacetic acid ammonium. The method comprises the following steps that 1, 2-oxo-2-furanylacetic acid and heavy metal salt are dissolved in water, an aqueous methoxyamine solution or aqueous methoxyamine salt solution is added at the temperature of 0 DEG C-10 DEG C, and the pH is regulated to 2.5-3.5; 2, heat preservation is performed for 2-7 h at the temperature of 5 DEG C-10 DEG C, and a 2-(alpha-methoxyimino)furanylacetic acid solution is obtained; 3, the pH of the 2-(alpha-methoxyimino)furanylacetic acid solution is regulated to 0.1-1.5 by adopting inorganic acid, the temperature is controlled at 15 DEG C-25 DEG C, extraction is performed through organic solvent, and organic phases are combined; 4, ammonia gas or liquid ammonia is introduced into the organic phases at the temperature of 0 DEG C-10 DEG C, the pH is regulated to 6.5-7.5, heat preservation is performed for 0.5-1.5 h to obtain a crude product, and after decoloration, concentration and crystallization are performed, the product is obtained. The method is high in yield and good in product quality.
Synthetic approach to gain insight into antigenic determinants of cephalosporins: In vitro studies of chemical structure-IgE molecular recognition relationships
Montanez, Maria Isabel,Mayorga, Cristobalina,Torres, Maria Jose,Ariza, Adriana,Blanca, Miguel,Perez-Inestrosa, Ezequiel
experimental part, p. 706 - 717 (2012/03/11)
Cephalosporins, after penicillins, are the most widely used antibacterial agents in infectious diseases and the cause of adverse immune reactions in the world. Whether a patient with a suspected allergy to a β-lactam can safely take a cephalosporin is often a matter of debate. However, there are no tests with enough sensitivity to detect allergy to cephalosporins. Understanding the way in which the drug metabolizes after protein conjugation is important if we are to make advances in the diagnosis of clinical allergy. Structural studies of cephalosporin-protein adducts have never been addressed successfully and are difficult to investigate. Our approach to determine the requirements involved in antigenic determinant structures consisted of designing and synthesizing a proposed skeleton that remains linked to the carrier protein after chemical degradation in cephalosporin conjugated to carrier proteins. In this study, a series of proposed epitopes were efficiently synthesized following a versatile methodology, involving the condensation of the R1 acyl side chains of native cephalosporins, with the nuclear fragment structures (derived from amino acids or other aminofunctionalized molecules). The final well-defined structures 1-4 (a-f), representing a fragment from the proposed cephalosporin-Lys(protein) adduct intermediate, consist of closely related low-molecular-weight molecules, differing only in the functional group at C-3 and the R1 side chains. They were assessed with sera from patients allergic to cephalosporins to study structure-IgE molecular recognition relationships. These IgE showed an enhanced recognition to proposed new skeleton epitopes with adequate functionality at C-3, with the specifities mainly related to the R1 acyl side chain. Thus, this study led us to refine the model haptenic structures of cephalosporins and gain insight into the chemical mechanism of epitope formation.
