Synthesis of isomers of 18F-labelled amino acid radiopharmaceutical

Abstract

To diagnose cancers with radiolabelled amino acid using positron emission tomography, we have constructed a separation and purification system for the production of L-¹⁸F-α-methyltyrosine (L-¹⁸FAmT). This system could provide radioprotection and consistent production of L-¹⁸FAmT. L-¹⁸FAmT was synthesized and purified and the efficiency of the system was examined. The radiochemical yield of L-¹⁸FAmT was 20.3 ± 5.1% (n = 5) based on the radioactivity trapped in the reaction vessel. The radiochemical purity was greater than 99.4 ± 0.3% (n = 5). The radiochemical stability in phosphate-buffered saline and human plasma was examined and little decomposition was observed by HPLC analysis. Our results indicate that the separation and purification system gave simple and quick synthesis of L-¹⁸FAmT with a large reduction in radiation exposure and consistent production of L-¹⁸FAmT.