Synthesis and evaluation of novel F-18 labeled fluoroarylvaline derivatives: potential PET imaging agents for tumor detection.

Two F-18 labeled fluoroarylvaline derivatives, methyl 2-(2-[(18)F]fluoro-4-nitrobenzamido)-3-methylbutanoate ([(18)F]1, [(18)F]MFNBMB) and its corresponding acid 2-(2-[(18)F]fluoro-4-nitrobenzamido)-3-methylbutanoic acid ([(18)F]2, [(18)F]FNBMBA), have been designed and synthesized, respectively, by our team. Meanwhile, we research on their biodistributions in mice model bearing S 180 tumor. Furthermore, we also carried out the biological evaluations of 2-[(18)F]fluorodeoxyglucose ([(18)F]FDG) and O-2-[(18)F]fluoroethyl-l-tyrosine (l-[(18)F]FET) in the same model for comparison with our targeting molecules [(18)F]1 and [(18)F]2. Excitingly, the tumor/blood (T/Bl) and tumor/brain (T/Br) ratios were 2.91, 7.06 at 30 min, 3.44, 5.61 at 60 min post injection for [(18)F]1, 2.32, 13.30 for [(18)F]2 at 30 min post injection, which were obviously superior to [(18)F]FDG and l-[(18)F]FET in the same model and demonstrated that [(18)F]1 and [(18)F]2, especially [(18)F]2, were potential PET imaging agents for tumor detection.