Effect of Tellurium Position on the Myocardial Uptake of Radioiodinated 18-Iodotellura-17-octadecenoic Acid Analogues

Article abstract of DOI:10.1021/jm00367a011

The effect of tellurium (Te) position on myocardial specifity and retention of fatty acids in which radioiodide is stabilized as a trans-(E)-vinyl iodode has been evaluated in rats.Five analogues of 18-iodo-17-octadecenoic acid (ICH=CH-R-Te-R'-COOH) with Te at positions 5,7,9,11, and 13 were prepared by coupling of a trans-diiodoalkene (ICH=CH-R-I) with the requisite sodium <(alkoxycarbonyl)alkyl>telluride substrate (NaTe-R'-COOR''; R''=Me or Et), followed by basic hydrolysis.By varying R and R', a series of analogues with a chain length of 18 carbon atoms was prepared.T he telluride substrates were generated in situ by NaBH4 reduction of the corresponding ditellurides, and the diiodoalkenes were prepared by sodium iodide-chloramine-T treatment of the corresponding vinylboronic acids <(HO)2BCH=CH-R-I)>.The vinylboronic acids were prepared by treatment of the terminal acetylenes (HC<*>C-R-I), synthesized from commercially available materials, with catecholborane.All new compounds were analyzed by TLC, NMR, MS, and elemental analyses.The 125I analogues <(E)-125ICH=CH-R-Te-R'-COOH> were prepared in the same manner and evaluated in rats (four per group).Heart uptake and retention were dependent upon the Te position.The analogue with Te at position 5 showed the most pronounced (5-min values) heart uptake (3.7-4.1 dose/g), myocardial retention, and heart/blood ratios (37:1) and is a candidate for radiolabeling with 123I and further evaluation as a myocardial imaging agent.