VII. ON THE MECHANISM OF ANTI-ANDROGENIC ACTION OF 16β-ETHYL-17β-HYDROXY-4-OESTREN-3-ONE (TSAA-291)

Abstract

ABSTRACT The mechanism of anti-androgenic action of a steroidal compound, TSAA-291, was summarized and discussed in reference to its drug-designing and structure-activity relationship. The target of the drug-design was to obtain a substance which is inactive in androgenic activity and is capable of antagonistically competing with androgen for the receptor. With this intention, the androgen molecule was rendered with a steric hindrance influencing upon the functional 17β-hydroxy group. Introduction of a bulky group at the steroidal position-13 or -16 led to anti-androgenic properties. Intense steric hindrance by introducing an enormously bulky group or complete elimination of the 17β-hydroxy group rather decreased the anti-androgenic activity. Of these anti-androgens thus synthesized, TSAA-291 proved to be the most active in the anti-androgen assay and also antagonistic against the uptake of [3H]testosterone by the rat ventral prostate.