title: Synthesis and evaluation of radioiodinated (E)-18-iodo-17-octadecenoic acid as a model iodoalkenyl fatty acid for myocardial imaging.
abstract: 125I-labeled (E)-18-iodo-17-octadecenoic acid (13) has been prepared and evaluated in rats to determine the myocardial uptake and retention and degree of in vivo deiodination of this model iodovinyl-substituted fatty acid, which contains no structural perturbation to inhibit metabolism. This new agent was prepared by NaI-chloramine-T treatment of (17-carbomethoxyheptadec-1-en-1-yl)boronic acid (11) prepared by catecholborane treatment of methyl 17-octadecynoate (10), followed by basic hydrolysis to the free acid (13). The pivotal substrate, 17-octadecynoic acid (9), was prepared by two new routes. The 125I-labeled acid 13 showed high myocardial uptake (1 h, 1.90-2.28% dose/g) with 45% washout after 2 h but lower heart/blood ratios in comparison to analogues containing the tellurium heteroatom. Deiodination was low for the first 2 h after injection (2 h, 61% dose/g). Excellent myocardial images were obtained in a dog with the 123I-labeled agent.
mesh_terms: D000818:Animals; D004285:Dogs; D006321:Heart / Q000000981:diagnostic imaging*; D007202:Indicators and Reagents; D007457:Iodine Radioisotopes; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D013058:Mass Spectrometry; D009206:Myocardium / Q000378:metabolism; D009829:Oleic Acids / Q000138:chemical synthesis* / Q000378:metabolism; D011877:Radionuclide Imaging; D051381:Rats; D013055:Spectrophotometry, Infrared; D013329:Structure-Activity Relationship; D014018:Tissue Distribution
chemical_list: D007202:Indicators and Reagents; D007457:Iodine Radioisotopes; D009829:Oleic Acids; C040054:18-iodo-17-octadecenoic acid