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Updated: May 23, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Solution structure of Fe(II)-azide-bleomycin derived from NMR data: transition from Fe(II)-bleomycin to
1Department of Chemistry, University of Wyoming, Laramie, WY 82071, USA. tlehmann@uwyo.edu
Abstract:
The coordination cage of the metal center in Fe(II)-bleomycin has been proposed to consist of the secondary amines in β-aminoalanine, the pyrimidinylpropionamide and imidazole rings, and the amide nitrogen in β-hydroxyhistidine as equatorial ligands, and the primary amine in β-aminoalanine and either the carbamoyl group in mannose or a solvent molecule occupying the axial sites. With the aim of supporting or not supporting coordination of a water molecule to the metal center in Fe(II)-bleomycin, the solution structure of Fe(II)-azide-bleomycin has been derived from NMR data. The structural changes that occur in Fe(II)-bleomycin upon azide binding have been monitored by comparing the experimental results with those obtained from the calculated structures for both bleomycin adducts. The results of this investigation strongly support a model of Fe(II)-bleomycin with six endogenous ligands as the most likely structure held in solution by this metallobleomycin in the absence of DNA.
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