Synthesis of a technetium-99m-labeled thymidine analog: a potential HSV1-TK substrate for non-invasive reporter gene expression imaging

{2-[5-(2'-Fluoro-2'-deoxyuridin-5-yl)pent-4(E)-enyl] [2-(2-mercaptoethyl)aminoethyl]aminoethanethiolato(3)-N,N' ,S,S'}-oxo[Tc-99m]technetium(V), a potential viral thymidine kinase substrate, was synthesized by coupling 2-fluoro-2'-deoxyuridine analog with a N2S2 radiometal chelator, followed by [Tc-99m]technetilim conjugation. The chemical structure of the radioactive probe was characterized by H-1 NMR and high resolution MS using Re-188 conjugated mimics. The radiochemical purity and yield were identified as 98% and 42%, respectively. (C) 2004 Published by Elsevier Ltd.