How to determine the number of inner-sphere water molecules in Lanthanide(III) complexes by 17O NMR spectroscopy. A technical note.
Lanthanide(III) complexes of polyaminocarboxylates are widely used in MRI as contrast agents. The paramagnetic properties of the metal ion contribute to the increase of (1)H relaxation rates, while the chelate offers a stable binding with the metal. The number of water molecules, coordinated directly to the Ln(III) ion, is very important for the relaxivity and, thus, the efficacy of these contrast agents. Here, we describe convenient methods to determine this parameter by measurement of Ln(III)-induced shifts of the water (17)O NMR resonance.
Djanashvili
Kristina
K
Laboratory of Biocatalysis and Organic Chemistry, Department of Biotechnology, Delft University of Technology, Julianalaan 136, 2628 BL Delft, The Netherlands.
Peters
Joop A
JA
D002627:Chemistry, Physical / Q000379:methods; D003287:Contrast Media / Q000494:pharmacology*; D007477:Ions; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation* / Q000379:methods*; D008280:Magnetics; D008956:Models, Chemical; D010103:Oxygen Isotopes; D011522:Protons; D012997:Solvents / Q000737:chemistry; D013696:Temperature; D014867:Water / Q000737:chemistry*
D003287:Contrast Media; D007477:Ions; D028581:Lanthanoid Series Elements; D010103:Oxygen Isotopes; D011522:Protons; D012997:Solvents; D014867:Water