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.

Graphical abstractWe 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 full-size imageDownload as PowerPoint slide