Iron(III)-chelating resins. 3. Synthesis, iron(III)-chelating properties, and in vitro antibacterial activity of compounds containing 3-hydroxy-2-methyl-4(1H)-pyridinone ligands

The synthesis, iron (III)-chelating properties, and antibacterial activity of several compounds containing the 3-hydroxy-2-methyl-4(1H)-pyridinone (HMP) moiety are described. Using the HMP derivatives iron (III) could be mobilized from iron (III)-binding proteins at physiological pH with a rate order of transferrin > lactoferrin > ferritin. Addition of HMP-containing compounds to a growth medium at a concentration of 20 mM/L resulted in a complete inhibition of the growth of Escherichia coli and about 90% inhibition for Listeria inocua after 7 h of incubation at 37 degrees C. After inhibition of bacteria growth by the HMP derivatives growth started again when ferric ions were added to the medium, which implies that the antibacterial activity is due to a limitation of iron available to the organisms.