<jats:title>Abstract</jats:title> <jats:p> From the culture medium of the phytopathogenic bacterium Pseudomonas corrugata, a lipopeptide siderophore was isolated that comprises interesting structural elements such as cyclic condensation products of the two amino groups of 2,4-diamino butyric acid with the carboxyl group of a second amino acid, and the rarely encountered L-threo-β-hydroxy histidine.