Synthesis of radiofluorinated analogs of m-tyrosine as potential L-dopa tracers via direct reaction with acetylhypofluorite.
The direct electrophilic radiofluorination of m-tyrosine using [18F]acetylhypofluorite was investigated. Results showed that this reaction was both rapid and efficient with recovered decay corrected yield of 71% radiofluorinated m-tyrosines based on starting [18F]acetylhypofluorite. Specific activity of the product obtained in this study was 100-200 mCi/mmol although 1-5 Ci/mmol are easily achievable with our improved production of [18F]AcOF. Three positional isomers were found and identified by 19F-NMR to be 2-, 4-, 6-fluoro-m-tyrosine with a distribution of 36:11:52, respectively. This measured distribution allowed the assignment of the radio-HPLC peaks. Biological studies are currently underway in our laboratory using these fluoro-m-tyrosines to determine which isomer would be most suited for the evaluation of the dopamine system by positron tomography.
DeJesus
O T
OT
Department of Medical Physics, University of Wisconsin-Madison 53706.
Sunderland
J J
JJ
Nickles
J R
JR
Mukherjee
J
J
Appelman
E H
EH
D001921:Brain / Q000000981:diagnostic imaging*; D005462:Fluorine Radioisotopes; D006801:Humans; D007553:Isotope Labeling / Q000379:methods; D007980:Levodopa / Q000032:analysis*; D014055:Tomography, Emission-Computed; D014443:Tyrosine / Q000031:analogs & derivatives*
D005462:Fluorine Radioisotopes; D014443:Tyrosine; D007980:Levodopa