677335-20-5Relevant academic research and scientific papers
Synthesis of a bifunctional monophosphinic acid DOTA analogue ligand and its lanthanide(III) complexes. A gadolinium(III) complex endowed with an optimal water exchange rate for MRI applications
Rudovsky, Jakub,Kotek, Jan,Hermann, Petr,Lukes, Ivan,Mainero, Valentina,Aime, Silvio
, p. 112 - 117 (2007/10/03)
A new bifunctional octa-coordinating ligand containing an aminobenzyl moiety, DO3APABn (H4DO3APABn = 1,4,7,10-tetraazacyclododecane-4,7,10-triacetic-1-{methyl[(4-aminophenyl)methyl] phosphinic acid}), has been synthesized. Its lanthanide(III) complexes contain one water molecule in the first coordination sphere. The high-resolution 1H and 31P spectra of [Eu(H2O) (DO3AP ABn)- show that the twisted square-antiprismatic form of the complexes is more abundant in respect to the corresponding Eu(III)-DOTA complex. The 1H NMRD and variable-temperature 17O relaxation measurements of [Gd(H2O)(DO3APABn)]- show that the water residence time is short (298TM = 16 ns) and falls into the optimal range predicted by theory for the attainment of high relaxivities once this complex would be endowed by a slow tumbling rate. The relaxivity (298r1 = 6.7 mM-1 s-1 at 10 MHz) is higher than expected as a consequence of a significant contribution from the second hydration sphere. These results prompt the use of [Gd(H 2O)(DO3APABn)]- as a building block for the set-up of highly efficient macromolecular MRI contrast agents.
