Potential tumor- or organ-imaging agents. 29. Radioiodinated esters and amides of 20-hydroxy- and 20-aminopregn-5-en-3 beta-ols.
Radioiodinated benzoyl esters and amides of epimeric 20-hydroxy- and 20-aminopregn-5-en-3 beta-ols were synthesized in an effort to find an agent that would be rapidly and selectively taken up by adrenal cortical tissue. Achievement of such a goal would provide a basis for the development of adrenal imaging agents superior to those currently available for clinical use. The iodobenzoyl derivatives were obtained by treating the appropriate epimer with 2-iodobenzoic acid in the presence of dicyclohexylcarbodiimide and 4-(dimethylamino)pyridine. The resulting esters and amides were readily labeled with radioiodine by isotope exchange with sodium iodide-125 in pivalic acid. Tissue distribution studies in female rats revealed that only the esters displayed appreciable adrenal specificity, and the ester having the same configuration at C-20 as cholesterol was significantly better than the corresponding C-20 epimer.
Haradahira
T
T
Department of Pharmacology, University of Michigan Medical School, Ann Arbor 48109.
Schwendner
S W
SW
Kojima
M
M
Counsell
R E
RE
D000302:Adrenal Cortex / Q000000981:diagnostic imaging; D000577:Amides / Q000138:chemical synthesis / Q000493:pharmacokinetics; D000818:Animals; D004952:Esters / Q000138:chemical synthesis / Q000493:pharmacokinetics; D005260:Female; D007457:Iodine Radioisotopes; D007463:Iodobenzoates / Q000138:chemical synthesis* / Q000493:pharmacokinetics; D007553:Isotope Labeling; D011284:Pregnenolone / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D051381:Rats; D011919:Rats, Inbred Strains; D013329:Structure-Activity Relationship; D014018:Tissue Distribution
D000577:Amides; D004952:Esters; D007457:Iodine Radioisotopes; D007463:Iodobenzoates; D011284:Pregnenolone