Synthesis of N-succinimidyl 4-[18F]fluorobenzoate, an agent for labeling proteins and peptides with 18F.
This protocol describes the step-by-step procedure for the synthesis of N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB), an agent widely used for labeling proteins and peptides with the positron-emitting radionuclide 18F. The protocols for the synthesis of unlabeled SFB and the quaternary salt precursor 4-formyl-N,N,N-trimethyl benzenaminium trifluoromethane sulfonate also are described. For the [18F]SFB synthesis, the quaternary salt is first converted to 4-[18F]fluorobenzaldehyde. Oxidation of the latter provides 4-[18F]fluorobenzoic acid, which is converted to [18F]SFB by treatment with N,N-disuccinimidyl carbonate. Using this method, [18F]SFB can be synthesized in decay-corrected radiochemical yields of 30%-35% and a specific radioactivity of 11-12 GBq micromol(-1). The total synthesis and purification time required is about 80 min, starting from delivery of the [18F]fluoride. [18F]SFB remains an optimal reagent for labeling proteins and peptides with 18F because of good conjugation yields and metabolic stability.
Vaidyanathan
Ganesan
G
Department of Radiology, Duke University Medical Center, Durham, North Carolina 27710, USA. ganesan.v@duke.edu
Zalutsky
Michael R
MR
D001565:Benzoates / Q000138:chemical synthesis*; D002851:Chromatography, High Pressure Liquid; D005462:Fluorine Radioisotopes / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry; D013388:Succinimides / Q000138:chemical synthesis*
D001565:Benzoates; D005462:Fluorine Radioisotopes; D011506:Proteins; D013388:Succinimides; C075713:N-succinimidyl-4-fluorobenzoate