Synthesis and biological evaluation of fatty acids conjugates bearing cyclopentadienyl-donors incorporated [99mTc/Re(CO)3]+ for myocardical imaging

• Tc-99m-labeled fatty acid is very important for evaluation of myocardial metabolism.
• 1b was radiolabeled by double ligand transfer reaction between ferrocene and 99mTc.
• 1b and 3b with chain branching has high uptake and prolongs retention in myocardium.

Four 99mTc-labeled fatty acid analogs, 1b, 2b, 3b, 4b were synthesized by a double ligand transfer reaction and theirs potential were investigated. The radiochemical yield of the radiotracers was from 11.7% to 30.3% (no decay corrected). Those compounds were found to be chemically stable when incubated in SD rat serum for 3 h at 37 °C. The biodistribution studies in mice showed that high radioactivity accumulated of Tc-99m complexes were observed, followed by moderate clearance from the heart. The maximum heart/blood ratio was 5.7 at 15 min postinjection of 1b. Metabolite analysis showed 1b was not metabolized by β-oxidation in the heart. These results suggest that 1b may be a promising radiotracer for evaluation of myocardial viability.

We synthesized 4 99mTc-labeled fatty acid analogs, 1b, 2b, 3b, 4b, and investigated their potentials as radiotracer for evaluating fatty acid metabolism in myocardium. 1b shows a more excellent potential than the others.Figure optionsDownload as PowerPoint slide