Synthesis of 99mTc(CO)3-NOET via [99mTc(OH2)3(CO)3]+ precursor and comparative biological studies with 99mTcN-NOET

The organometallic precursor fac-[99mTc(CO)3(H2O)3]+ was reacted with N-ethoxy, N-ethyl dithiocarbamate (NOET) in phosphate buffered saline (pH 7.4) at room temperature for 30 minutes to produce the 99mTc(CO)3-NOET complex. The radiochemical purity (RCP) of the product was over 90% as measured by thin layer chromatography (TLC). No decomposition of the complex at room temperature (RT) was observed over a period of 6 hours. Its partition coefficient indicated that it was a lipophilic complex. The biodistribution comparison in mice of the 99mTc(CO)3-NOET complex and the 99mTcN-NOET complex showed that the former had a lower heart and brain uptake as compared to that of the latter, suggesting the incorporation of the [99mTc(CO)3]+ core into the NOET ligand does not improve the biological features as a myocardial imaging agent.