1242003-18-4Relevant articles and documents
A triazacyclononane-based bifunctional phosphinate ligand for the preparation of multimeric68GA tracers for positron emission tomography
Notni, Johannes,Hermann, Petr,Havlickova, Jana,Kotek, Jan,Kubicek, Vojtech,Plutnar, Jan,Loktionova, Natalia,Riss, Patrick Johannes,Roesch, Frank,Lukes, Ivan
, p. 7174 - 7185 (2010)
For application in positron emission tomography (PET), PrP9, a N,N′,N″-trisubstituted triazacyclononane with methyl(2-carboxyethyl) phosphinic acid pendant arms, was developed as 68Ga3+ complexing agent. The synthesis is short and inexpensive. GaIII and FeIII complexes of PrP9 were characterized by single-crystal X-ray diffraction. Stepwise protonation constants and thermodynamic stabilities of metal complexes were determined by potentiometry. The GaIII complex possesses a high thermodynamic stability (log K[GaL]=26.24) and a high degree of kinetic inertness. 68Ga labeling of PrP9 is possible at ambient temperature and in a wide pH range, also at pH values as low as 1. This means that for the first time, the neat eluate of a TiO2based 68Ge/68Ga generator (typically consisting of 0.1M HCl) can be directly used for labeling purposes. The rate of 68Ga activity incorporation at pH 3.3 and 20°C is higher than for the established chelators DOTA and NOTA. Tris-amides of PrP9 with amino acid esters were synthesized to act as models for multimeric peptide conjugates. These conjugates exhibit radiolabeling properties similar to those of unsubstituted PrP9.
