Desferrioxamines

Desferrioxamines are a family of siderophores produced by various actinomycetes, notably Streptomyces species, that function to scavenge ferric iron (Fe3+) from the environment. They play a key role in microbial iron acquisition under iron-limited conditions by binding Fe3+ and delivering it to bacterial uptake systems. The most studied member is desferrioxamine B, also known clinically as deferoxamine.

Chemistry and coordination chemistry: Desferrioxamine B is a linear molecule bearing three N-hydroxyamide groups that coordinate Fe3+ in a hexadentate fashion. The resulting ferrioxamine B complex is highly stable and is typically excreted in urine. The desferrioxamine family includes several congeners (for example A, C, D, and E) that share a common hydroxamate-based iron-binding motif and similar iron-chelating properties.

Biosynthesis and biology: In Streptomyces and related bacteria, desferrioxamines are produced via nonribosomal peptide synthetase pathways, assembling polyamine-derived units into the siderophore structure. Desferrioxamines enable microbes to compete for iron in nutrient-poor environments, and uptake systems recognize ferri-desferrioxane complexes through specific siderophore receptors.

Clinical and research relevance: Desferrioxamine B is used clinically as an iron chelator to treat iron overload from chronic transfusion therapy or metabolic disorders. It forms a stable ferrioxamine complex that is eliminated renally. Beyond clinical use, desferrioxamines serve as model compounds in research on iron metabolism and can be employed to study siderophore–receptor interactions or to label ferrioxamine complexes for imaging and biochemical applications.