Transformations of Steroid Esters by Fusarium culmorum

Keywords The course of transformations of the pharmacological steroids: testosterone propionate, 4-chlorotestosterone acetate, 17β-estradiol diacetate and their parent alcohols in Fusarium culmorum AM282 culture was compared. The results show that this microorganism is capable of regioselective hydrolysis of ester bonds. Only 4-ene-3-oxo steroid esters were hydrolyzed at C-17. 17β-Estradiol diacetate underwent regioselective hydrolysis at C-3 and as a result, estrone - the main metabolite of estradiol - was absent in the reaction mixture. The alcohols resulting from the hydrolysis underwent oxidation at C-17 and hydroxylation. The same products (6β- and 15α-hydroxy derivatives) as from testosterone were formed by transformation of testosterone propionate, but the quantitative composition of the mixtures obtained after transformations of both substrates showed differences. The 15α-hydroxy deriv­atives were obtained from the ester in considerably higher yield than from the parent alcohol. The presence of the chlorine atom at C-4 markedly reduced 17β-saponification in 4-chloro- testosterone acetate. Only 3β,15α-dihydroxy-4α-chloro-5α-androstan-17-one (the main prod­uct of transformation of 4-chlorotestosterone) was identified in the reaction mixture. 6β- Hydroxy-4-chloroandrostenedione, which was formed from 4-chlorotestosterone, was |not de­tected in the extract obtained after conversion of its ester.