Gd-complexes of new arylpiperazinyl conjugates of DTPA-bis(amides): Synthesis, characterization and magnetic relaxation properties

Abstract

Two new DTPA-bis(amide) based ligands conjugated with the arylpiperazinyl moiety were synthesized and subsequently transformed into their corresponding Gd(III) complexes 1 and 2 of the type [Gd(L)H 2 O]·nH 2 O. The relaxivity (R 1) of these complexes was measured, which turned out to be comparable with that of Omniscan®, a commercially available MRI contrast agent. The cytotoxicity studies of these complexes indicated that they are non-toxic, which reveals their potential and physiological suitability as MRI contrast agents. All the synthesized ligands and complexes were characterized with the aid of analytical and spectroscopic methods, including elemental analysis, 1 H-NMR, FT-IR, XPS and fast atom bombardment (FAB) mass spectrometry.