Preparation of the N-(4'-hydroxy-[3'-125I]iodophenethyl)-6-(4-O-diethylstilbestryl)hexanam ide for diethylstilbestrol radioimmunoassays.
The synthesis of a radioiodinated diethylstilbestrol (DES) derivative is described. This derivative was prepared by coupling the previously synthesized active ester of 6-(4-O-diethylstilbestryl)hexanoic acid with mono-[125I]iodotyramine in dry tetrahydrofuran (20 to 22 C, 16 hours). The mono-[125I]iodotyramine was prepared using a chloramine-T method and purified by paper electrophoresis. The final product, N-(4'-hydroxy-[3'-125I]iodophenethyl)-6-(4-O- diethylstilbestryl)hexanamide, was separated by thin-layer chromatography (cyclohexane/ethanol/NH4OH 2.5 N/acetone; 40:50:5:20, v/v/v/v); it was stable for 2 months in ethanol at 4 C and had a specific activity higher than 540 Ci/mmol. The [125I]DES amide synthesized was found to retain the immunoreactivity of DES, since it competed with [3H]DES or DES in an in vitro radioimmunoassay system for the binding sites of a rabbit anti-DES antibody; thus, it seems to be capable of replacing the tritiated tracer used so far in DES radioimmunoassays.
Economou
E V
EV
Radioimmunochemistry Laboratory, Institute of Radioisotopes/Radiodiagnostic Products, Athens, Greece.
Livaniou
E
E
Evangelatos
G P
GP
Ithakissios
D S
DS
D001667:Binding, Competitive; D002700:Chloramines; D002855:Chromatography, Thin Layer; D004054:Diethylstilbestrol / Q000031:analogs & derivatives* / Q000032:analysis* / Q000138:chemical synthesis / Q000737:chemistry; D004590:Electrophoresis, Paper; D005663:Furans / Q000737:chemistry; D007457:Iodine Radioisotopes; D007462:Iodobenzenes / Q000138:chemical synthesis* / Q000737:chemistry; D007553:Isotope Labeling; D011863:Radioimmunoassay; D014105:Tosyl Compounds; D014439:Tyramine / Q000737:chemistry
D002700:Chloramines; D005663:Furans; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D014105:Tosyl Compounds; C016300:chloramine-T; C074455:N-(4'-hydroxy-3'-iodophenethyl)-6-(4-O-diethylstilbestryl)hexanamide; C018674:tetrahydrofuran; D004054:Diethylstilbestrol; D014439:Tyramine