Synthesis and ESR study of new dihydroxamic acid siderophores S as scavengers of hydroxyl radicals

Five new dihydroxamic acid ligands (L) (8, 10a, 10b, 10c and 13) have been synthesised and characterised as potential chelating agents for iron (Fe3+). The log stability constants of Fe2L3 and FeL+ from Fe3+ and L2− have been estimated to be logβ=61.96 and logβ1=22.8 respectively. The ability of these compounds to scavenge hydroxyl radicals (oOH) responsible for cell damage have been studied by esr spectroscopy.