The authors thank the National Institutes of Health (EB-04285, M.W.) and (CA-84697 and RR-02584, A. D. S.) and the Robert A. Welch Foundation (AT-584) for financial support for financial support of this work.
Gadolinium compounds -- Applications to magnetic resonance imaging, Contrast media (Diagnostic imaging) -- Synthesis, Ligands (Biochemistry) -- Synthesis
The gadolinium(III) complex of S-SSSS-NO2BnDOTMA exhibits water exchange kinetics that are optimal for use in high relaxivity or targeted contrast agents. However, the synthesis of this ligand is hampered by the steric encumbrance imparted upon the cyclen ring by the nitrobenzyl substituent. A relatively simple modification has been used to enable the synthesis of larger quantities of a bifunctional ligand that retains similar fast water exchange properties. The gadolinium complex of S-SSS-NO2BnDO3MA-1A is shown to retain the rapid water exchange kinetics characteristic of a twisted square antiprismatic (TSAP) coordination geometry (τM = 6 ± 0.4 ns).
Woods, M., Botta, M., Avedano, S., Wang, J., & Sherry, A. D. (2005). Towards the rational design of MRI contrast agents: a practical approach to the synthesis of gadolinium complexes that exhibit optimal water exchange. Dalton Transactions, (24), 3829-3837.