Synthesis of 6-[18F]fluoropyridoxal and radioactivity distribution in rat at 60 min.
6-[18F]Fluoropyridoxal was synthesized by the flourination of a propylamine derivative of pyridoxal (pyridoxal Schiff base) with 18F-labelled acetylhypofluorite. Two different fluorinating agents, 5% F2 in N2 and acetylhypofluorite, were investigated with nonradioactive material. The evaluation of reactions in CH3CN and chloroform showed CH3CN to be the better solvent and CH3COOF to be the better fluorinating reagent. The synthesis gave a radiochemical yield of about 18% (expressed at the end of synthesis) and required 35-40 min to complete. The specific activity of the final radiopharmaceutical at the end of the synthesis was about 25.9 GBq/mmol (700 mCi/mmol). The tissue distribution of 6-fluoropyridoxal in rat at 60 min is also reported. A large concentration in liver and kidney indicates that this radiopharmaceutical could be of special interest in the imaging of liver functions. The concentration in the brain might also allow in vivo PET imaging of the 6-(fluoropyridoxal) uptake if a high efficiency PET scanner is used.
Montreal Neurological Institute and Hospital, McGill University, Quebec, Canada.
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Diksic
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Trani
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Nagahiro
D000818:Animals; D001921:Brain / Q000000981:diagnostic imaging; D005462:Fluorine Radioisotopes; D007668:Kidney / Q000000981:diagnostic imaging; D008099:Liver / Q000000981:diagnostic imaging; D011730:Pyridoxal / Q000031:analogs & derivatives* / Q000138:chemical synthesis; D011877:Radionuclide Imaging; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014018:Tissue Distribution
D005462:Fluorine Radioisotopes; D011730:Pyridoxal; C044385:6-fluoropyridoxal