[Microbial 3-O-demethylation and 3-O-methylation of estratrienes].

Estradiol-3-methylether, estrone-3-methylether, 17alpha-ethinyl-estradiol-3-methylether and other 17alpha-substituted estratrienes were 3-O-demethylated to free 3-hydroxy compounds by fermentation with Corynebacterium sp. A hydroxy groupp in position 6alpha or 6beta prevented the reaction. The opposite reaction, methylation of the 3-hydroxy group of estratrienes, was performed using Mycobacterium smegmatis. The substrate specifity of this methylation was low. Analogies of these microbial reactions to steroid metabolism in mammalian organism are discussed.