We synthesized [18 F]trifluoromethyl-l-tryptophan ([18 F]CF3 -l-Trp) using Cu(I)-mediated [18 F]trifluoromethylation to image serotonergic system. Radiochemical yield was 6 ± 1.5% (n = 9), and radiochemical purity was over 99%. The molar activity was 0.44 to 0.76 GBq/μmol. [18 F]CF3 -l-Trp was stable for up to 6 hours in mouse and human sera at 37°C. Protein-binding was 0.26 ± 0.03% and 0.34 ± 0.02% in human and mouse serum at 60 minutes, respectively. In conclusion, enantiopure [18 F]CF3 -l-Trp was synthesized as a feasible imaging agent for the serotonergic system.
Keywords: 5-HT; CF3-l-Trp; amino acid; serotonin; tryptophan.
© 2019 John Wiley & Sons, Ltd.