The Crystal and Molecular Structures of Ceftizoxime and Ceftizoxime Monohydrochloride Monohydrate

Abstract

The crystal and molecular structures of ceftizoxime (CZX) and its monohydrochloride monohydrate (CZX-HCl) were elucidated by X-ray structure analysis. The aminothiazolyl-methoxyimino group in the cephem C(7) substituent of both substances is in a quasi coplane, as in other cephalosporins with this C(7) substituent. The orientations of these coplanes to the cephem moiety vary such that the rotation of the cephem C(7) side chain seems not to be rigidly constrained. The exocyclic amido groups in both CZX and CZX-HCl are also planar, with intermolecular hydrogen bonds between the nitrogen and the oxygen atoms of adjacent molecules. The conformations resemble those described for the peptide bond moiety in proteins.