Abstract: The synthesis, radiolabeling and in vitro evaluation of new silicon-fluoride acceptor (SiFA) derivatized D2-receptor ligands is reported. The SiFA-technology simplifies the introduction of fluorine-18 into target specific biomolecules for Positron-Emission-Tomography (PET). However, one of the remaining challenges, especially for small molecules such as receptor-ligands, is the bulkiness of the SiFA-moiety. We therefore synthesized four Fallypride SiFA-conjugates derivatized either directly at the benzoic acid ring system (SiFA-DMFP, SiFA-FP, SiFA-DDMFP) or at the butyl-side chain (SiFA-M-FP) and tested their receptor affinities. We found D2-receptor affinities for all compounds in the nanomolar range (Ki(SiFA-DMFP) = 13.6 nM, Ki(SiFA-FP) = 33.0 nM, Ki(SiFA-DDMFP) = 62.7 nM and Ki(SiFA-M-FP) = 4.21 nM). The radiofluorination showed highest yields when 10 nmol of the precursors were reacted with [18F]fluoride/TBAHCO3 in acetonitrile. After a reversed phased cartridge purification the desired products could be isolated as an injectable solution after only 10 min synthesis time with radiochemical yields (RCY) of more than 40% in the case of SiFA-DMFP resulting in specific activities >41 GBq/µmol (>1,100 Ci/mmol). Furthermore, the radiolabeled products were shown to be stable in the injectable solutions, as well as in human plasma, for at least 90 min.
This is an open access article distributed under the
Creative Commons Attribution License which permits unrestricted use, distribution,
and reproduction in any medium, provided the original work is properly cited.
Export to BibTeX
MDPI and ACS Style
Iovkova-Berends, L.; Wängler, C.; Zöller, T.; Höfner, G.; Wanner, K.T.; Rensch, C.; Bartenstein, P.; Kostikov, A.; Schirrmacher, R.; Jurkschat, K.; Wängler, B. t-Bu2SiF-Derivatized D2-Receptor Ligands: The First SiFA-Containing Small Molecule Radiotracers for Target-Specific PET-Imaging. Molecules 2011, 16, 7458-7479.
Iovkova-Berends L, Wängler C, Zöller T, Höfner G, Wanner KT, Rensch C, Bartenstein P, Kostikov A, Schirrmacher R, Jurkschat K, Wängler B. t-Bu2SiF-Derivatized D2-Receptor Ligands: The First SiFA-Containing Small Molecule Radiotracers for Target-Specific PET-Imaging. Molecules. 2011; 16(9):7458-7479.
Iovkova-Berends, Ljuba; Wängler, Carmen; Zöller, Thomas; Höfner, Georg; Wanner, Klaus Theodor; Rensch, Christian; Bartenstein, Peter; Kostikov, Alexey; Schirrmacher, Ralf; Jurkschat, Klaus; Wängler, Björn. 2011. "t-Bu2SiF-Derivatized D2-Receptor Ligands: The First SiFA-Containing Small Molecule Radiotracers for Target-Specific PET-Imaging." Molecules 16, no. 9: 7458-7479.