Radiosynthesis and preliminary biological evaluation of the 2-[F-18]fluoropropionic acid enantiomers for tumor PET imaging

摘要

The aim of this study was to synthesize the optically pure [F-18]FPA, and to investigate the diagnostic value of different isomers. Semi-automated radiosynthesis of R-[F-18]FPA or S-[F-18]FPA was respectively from the chiral precursor (S)- or (R)-ethyl 2-(((trifluoromethyl)sulfonyl)oxy)propanoate via a two-step reaction and performed on the commercial FDG synthesizer. The improved radiochemical yields of R-[F-18]FPA and S-[F-18]FPA were 30-40% (decay-uncorrected, n = 10) in 35 min. There was no significant difference on the biodistribution of two enantiomers in normal mice (P 0.05), but positron emission tomography imaging demonstrated that R-[F-18]FPA was more suitable for PC3 tumor imaging than S-[F-18]FPA and [F-18]FDG.