Design of Radioiodinated Pharmaceuticals: Structural Features Affecting Metabolic Stability towards in Vivo Deiodination

• Published in: European journal of organic chemistry Vol. 2017; no. 24; pp. 3387 - 3414
• Main Authors: Cavina, Lorenzo, van der Born, Dion, Klaren, Peter H. M., Feiters, Martin C., Boerman, Otto C., Rutjes, Floris P. J. T.
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 30.06.2017; John Wiley and Sons Inc
• Subjects: Biocompatibility; Carbon; Fragmentation; In vivo methods and tests; Insertion; Iodine; Iodine isotopes; Isotopes; Isotopic labeling; Medicine; Metabolism; Microreview; Nuclear medicine; Pharmaceuticals; Radioiodinated pharmaceuticals; Radiolabeling; Structural stability; Therapy; Tracers; Radiolabeling; Metabolism; Radioiodinated pharmaceuticals; Iodine; Isotopic labeling
• ISSN: 1434-193X; 1099-0690
• DOI: 10.1002/ejoc.201601638

Radioiodinated pharmaceuticals are convenient tracers for clinical and research investigations because of the relatively long half‐lives of radioactive iodine isotopes (i.e., 123I, 124I, and 131I) and the ease of their chemical insertion. Their application in radionuclide imaging and therapy may, however, be hampered by poor in vivo stability of the C–I bond. After an overview of the use of iodine in biology and nuclear medicine, we present here a survey of the catabolic pathways for iodinated xenobiotics, including their biodistribution, accumulation, and biostability. We summarize successful rational improvements in the biostability and conclude with general guidelines for the design of stable radioiodinated pharmaceuticals. It appears to be necessary to consider the whole molecule, rather than the radioiodinated fragment alone. Iodine radionuclides are generally retained in vivo on sp2 carbon atoms in iodoarenes and iodovinyl moieties, but not in iodinated heterocycles or on sp3 carbon atoms. Iodoarene substituents also have an influence, with increased in vivo deiodination in the cases of iodophenols and iodoanilines, whereas methoxylation and difluorination improve biostability. Radioiodinated pharmaceuticals are convenient tracers for clinical and research investigations. Their application may, however, be hampered by poor in vivo stability of the C–I bond. We present here a survey of the catabolic pathways for iodinated xenobiotics, summarizing general guidelines for the design of biologically stable radioiodinated pharmaceuticals.