Siderophore analogues. Synthesis and chelating properties of a new macrocyclic trishydroxamate ligand

Abstract

A new iron(III)-specific ligand, 1,5,9-triazacyclododecane-N,N′,N″-tris(N-methylacetohydroxamic acid) H₃L, containing three hydroxamic acid groups as pendant arms on a macrocyclic triamine backbone, has been synthesized and characterized. Its acid–base and chelating properties with iron(III) and copper(II) ions have been studied by potentiometric and spectrophotometric techniques. The mechanism of electron transfer as well as the kinetics of dissociation and stability constants of reduced species, which are thought to be important in the biological activity of this siderophore analogue, have been studied by voltammetric methods. This ligand has proved to be biologically active and its properties were compared with ferrichrome and ferrioxamine B.