Synthesis and characterization of new beta-diketo derivatives with iron chelating ability.

Here we report the synthesis, the characterization and a theoretical study on new glycosylated phenyl substituted beta-diketones; two classes of compounds are obtained according to the condensation reaction: central and side derivatives. Their iron(III) chelating ability is tested by means of UV-visible (UV-vis), potentiometric and NMR techniques. The conformation of central derivatives does not allow any metal chelation, while side derivatives bind iron(III) through the beta-dioxo moiety. The glycosyl moiety does not interact with metal ion but it helps to stabilize metal/ligand (1/3) complexes by means of hydrophylic interactions. The pK(a) of the ligands and the stability constants of their Fe(III) complexes are evaluated by means of UV-vis spectroscopy and potentiometry. A comparison with other iron-chelating agents, on the basis of lipophilicity and the pFe(III), is finally reported.