Synthesis, physico-chemical properties, and antimicrobial evaluation of a new series of iron(III) hexadentate chelators

A series of related 3-hydroxypyridin-4-one hexadentate ligands have been synthesized. These chelators were found to possess a high affinity for iron(III), with a pFe value of about 30. As iron is a critical element to the survival of bacteria, these chelators were predicted to inhibit the growth of bacteria by disrupting bacterial iron absorption. Indeed, they were demonstrated to possess appreciable inhibitory activity against both Gram-positive and Gram-negative bacteria, and therefore, they have potential as antimicrobial agents. 1c and 1g were found to be particularly effective against Gram-negative species. Graphical Abstract: A series of related 3-hydroxypyridin-4-one hexadentate ligands have been synthesized. These chelators were found to possess a high affinity for iron(III), and exhibit appreciable inhibitory activity against both Gram-positive and Gram-negative bacteria, and therefore, they have potential as antimicrobial agents. [Figure not available: see fulltext.]