Synthesis and biodistribution of 99mTc-N, N'-disubstituted N2S2 deribvatives for myocardial SPECT agents

99mTc labeled lipophilic cations have been widely used for myocardial SPECT, like 99mTc-sestamibi and 99mTc-tetrofosmin. We synthesized novel +1 charged lipophilic 99mTc-labeled N, N'-disubstituted N2S2 derivatives and investigated their biodistribution. 99mTc-N, N'-disubstituted N2S2 derivatives were proved to have positive charge by electrophoresis and all the 99mTc-labeled compounds showed labeling efficiencies of higher than 93%. In biodistribution study, the myocardial uptake of 99mTc-N, N'-dimethylN2S2, 99mTc-N, N'-diethylN2O2, 99mTc-N, N'-bis(methoxyethyl)-N2S2 and 99mTc-N, N'-bis(ethoxyethyl) N2S2 were 5.4 ± 1.0, 3.0 ±0.2, 4.3 ± 0.5, and 7.2 ± 1.0% ID/g at 10 min, respectively, and 5.3 ± 1.6, 2.1 ±0.4, 1.0 ± 0.2, and 1.7 ± 0.0% ID/g at 2 hr, respectively