Highly stable acyclic bifunctional chelator for 64 Cu PET imaging
2011; R. Oldenbourg Verlag; Volume: 99; Issue: 10 Linguagem: Inglês
10.1524/ract.2011.1823
ISSN2193-3405
AutoresSabah Abada, Alexandre Lecointre, Isabelle Déchamps‐Olivier, Carlos Platas‐Iglesias, Câline Christine, Mourad Elhabiri, Loı̈c J. Charbonnière,
Tópico(s)Magnetism in coordination complexes
ResumoAbstract Ligand L 1 , based on a pyridine scaffold, functionalized by two bis(methane phosphonate)aminomethyl groups, was shown to display a very high affinity towards Cu(II) (log K CuL =22.7) and selectivity over Ni(II), Co(II), Zn(II) and Ga(III) (Δ log K ML >4) as shown by the values of the stability constants obtained from potentiometric measurements. Insights into the coordination mode of the ligand around Cu(II) cation were obtained by UV-Vis absorption and EPR spectroscopies as well as density functional theory (DFT) calculations (B3LYP model) performed in aqueous solution. The results point to a pentacoordination pattern of the metal ion in the fully deprotonated [CuL 1 ] 6− species. Considering the beneficial thermodynamic parameters of this ligand, kinetic experiments were run to follow the formation of the copper(II) complexes, indicating a very rapid formation of the complex, appropriat e for 64 Cu complexation. As L 1 represents a particularly interesting target within the frame of 64 Cu PET imaging, a synthetic protocol was developed to introduce a labeling function on the pyridyl moiety of L 1 , thereby affording L 2 , a potential bifunctional chelator (BFC) for PET imaging.
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