Catecholate Siderophores from Chryseomonas luteola*

Under iron-limited conditions many bacterial species biosynthesize Fe3+ complexing compounds, so-called siderophores. Their most common struc­ tural features are hydroxamate and/or catecholate units, the latter ones mostly derived from 2,3-dihydroxybenzoic acid attached to amino acids, amino alcohols or aliphatic diamines. We wish now to re­ port the isolation and structure elucidation of two catecholate siderophores from Chryseomonas lu­ teola. One of them proved to be chrysobactin (1) which had been obtained before from Erwinia chrysanthemi (Persmark et al., 1989) and from Ser­ ratia marcescens (Ehlert et al., 1994). The second one named chryseomonin could be shown to be 6(l-pyridinio-)chrysobactin, i.e., N2-[2,3-dihydroxy6-(l-pyridinio)-benzoyl]-lysylserine (2), a novel type of catecholate siderophores.