Tenacibactins K-M, cytotoxic siderophores from a coral-associated gliding bacterium of the genus Tenacibaculum .

HPLC/DAD-based chemical investigation of a coral-associated gliding bacterium of the genus Tenacibaculum yielded three desferrioxamine-class siderophores, designated tenacibactins K ( 1 ), L ( 2 ), and M ( 3 ). Their chemical structures, comprising repeated cadaverine-succinic acid motifs terminated by a hydroxamic acid functionality, were elucidated by NMR and negative MS/MS experiments. Compounds 1 - 3 were inactive against bacteria and a yeast but displayed cytotoxicity against 3Y1 rat embryonic fibroblasts and P388 murine leukemia cells at GI 50 in submicromolar to micromolar ranges. Their iron-chelating activity was comparable to deferoxamine mesylate.