Siderochelin, a new ferrous-ion chelating agent produced by Nocardia

A new ferrous-ion chelating agent, siderochelin, was isolated from fermentation broths of Nocardia sp. SC 11,340. Siderochelin was produced by conventional submerged culture and purified by solvent extraction and recrystallization. The antibiotic was crystallized from acetonitrile as a mixture of diastereoisomers. The molecular formula of siderochelin was determined as C11H13N3O3 on the basis of elemental analysis and mass spectrometry, and the structure was elucidated by X-ray crystallography. The compound shows a broad spectrum of antimicrobial activity, being active against bacteria, fungi and protozoa.