Synthesis and stability of S‐(2‐[18F]fluoroethyl)‐L‐homocysteine for potential tumour imaging |
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Authors: | Thomas Bourdier Christopher J R Fookes Tien Q Pham Ivan Greguric Andrew Katsifis |
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Institution: | Radiopharmaceuticals Research Institute, Australian Nuclear Science and Technology Organisation, PMB 1 Menai, NSW 2234, Sydney, Australia |
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Abstract: | The F‐18 labelled methionine derivative S‐(2‐18F]fluoroethyl)‐L‐homocysteine (18F]FEHCys) was prepared by a one‐pot two‐step synthesis via the protected S‐(2‐bromoethyl)‐L‐homocysteine 1 and S‐(2‐chloroethyl)‐L‐homocysteine 2 precursors. The bromoethyl derivative 1 gave higher radiochemical yields (40% at 5 min) at 100°C compared with the chloro‐analogue (22% at 100°C in 30 min). However, 18F]FEHCys was found to be unstable in aqueous systems being transformed to the corresponding hydroxyl derivative within 20 min. Copyright © 2008 John Wiley & Sons, Ltd. |
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Keywords: | S‐(2‐[18F]fluoroethyl)‐L‐homocysteine FEHCys amino acids nucleophilic [18F]‐fluorination |
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