The Pseudomonas siderophore quinolobactin is synthesized from xanthurenic acid, an intermediate of the kynurenine pathway.

To cope with iron deficiency fluorescent pseudomonads produce pyoverdines which are complex peptidic siderophores that very efficiently scavenge iron. In addition to pyoverdine some species also produce other siderophores. Recently, it was shown that Pseudomonas fluorescens ATCC 17400 produces the siderophore quinolobactin, an 8-hydroxy-4-methoxy-2-quinoline carboxylic acid (Mossialos, D.