The effect of lipophilic substituents on the biological properties of EDTA complexes containing paramagnetic metal ions.
Complexes of the radioactive paramagnetic metal ions 51Cr(III), 54Mn(II), 59Fe(III), 57Co(II), 64Cu(II) and 153Gd(III) were prepared with EDTA and its derivative containing the lipophilic 1-(4-methylphenyl)-group (MPEDTA), together with the corresponding 99mTc-compounds. The formation of these complexes was verified by electrophoresis and they were screened for potential use as MRI hepatobiliary contrast agents by biodistribution studies in mice. In this series, the MPEDTA complexes of 54Mn(II) and 64Cu(II) showed increased urinary excretion compared to the unsubstituted EDTA complexes, while the MPEDTA complexes of 99mTc, 59Fe, 57Co, 153Gd and particularly 51Cr demonstrated improved hepatobiliary excretion. Further lipophilic substitution should enhance this property but the preparation of such ligands is complicated by cyclisation reactions.
D000818:Animals; D004492:Edetic Acid / Q000378:metabolism*; D005260:Female; D007700:Kinetics; D008670:Metals / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D011868:Radioisotopes; D014018:Tissue Distribution
D008670:Metals; D011868:Radioisotopes; D004492:Edetic Acid