Effects of 1-alkyl substitution on the biological action in a series of androstanes

Abstract The estimation of biological action of a series of androstane derivative reveals that the alkyl substitution in the position 1 is always accompanied by a decrease of activity in the prostates and seminal vesicles. On the basic of this finding and by the analysis of the data mentioned in the literature, we presume that the biological reaction of androgena starta by at least a partial penetration into the predisposed space of the receptor. The fit of the molecule to the receptor in m. levator ani seems to be subject to more complicated regularities.