Synthesis of (4-[18F]fluorophenyl)triphenylphosphonium as a potential imaging agent for mitochondrial dysfunction

Tetraphenylphosphonium (TPP) cation is able to function as a molecular probe for monitoring mitochondrial disease. The F-18 labeled TPP, (4-[F-18]fluorophenyl) triphenylphosphonium ((FTPP)-F-18), was therefore developed as a PET radioligand for in vivo molecular imaging of mitochondrial dysfunction. (FTPP)-F-18 was synthesized via direct nucleophilic substitution of no-carrier-added [F-18]fluoride with the precursor 4-nitrophenyltriphenylphosphonium. After purification by HPLC, the average radiochemical yield was determined to be 10-15% and the specific activity was >500 Ci/mmol at the end of synthesis. The total synthesis time was within 60 min, and the radiochemical purity of the (FTPP)-F-18 was above 95%. Copyright (C) 2005 John Wiley Sons, Ltd.