The synthesis of tritium-labeled 16 alpha,17 alpha-cyclohex-3 '-eno-progesterone as probe for the study of steroid-receptor binding

Tritium-labeled 16 alpha,17 alpha-cyclohex-3'-en-pregn-4-en-3,20-dione (16 alpha,17 alpha-cyclohex-3'-enoprogesterone) with specific activity of 44 Ci /mmol, required in studying of binding with progesterone receptors, has bee n obtained by homogenous catalytic hydrogenation of 16 alpha,17 alpha-cyclo hex-3'-eno-pregna-1,4-dien-3,20-dione with gaseous tritium and subsequent s eparation of the mixture by HPLC. Biological testing has shown it to bind t o rat uterine progesterone receptor with an affinity comparable with that o f progesterone itself. (C) 1999 Academic Press.