Synthesis, radio-LC-MS analysis and biodistribution in mice of 99mTc-NIM-BAT

S,S'-bis-trityl-N-BOC-1,2-ethylenedicysteamine (S,S'-bis-trityl-N-BOC-BAT) was conjugated to 2-nitroimidazole (NIM) through a propylene spacer in order to provide a precursor for a potential technetium-99m labelled hypoxia tracer. For labelling with technetium-99m, a two-step one-pot procedure was developed consisting of deprotection of the ligand by heating in mild acidic conditions and subsequent exchange labelling in the presence of SnCl2, tartrate and (TcO4-)-Tc-99m. The labelling reaction mixture was analyzed using electrospray radio-LC-MS and the observed mass spectrum corresponding to the main radiometric peak was in accordance with the predicted structure of oxo-Tc(V)-NIM-BAT. Tc-99m-NIM-BAT was purified using RP-HPLC and its biodistribution was evaluated in normal mice at 10 min and 4 h p.i. Tc-99m-NIM-BAT was cleared from plasma mainly by hepatobiliary excretion. Copyright (C) 2003 John Wiley Sons, Ltd.