Studies on the Metabolism of C₁₉ Steroids in Rat Liver: 2. Biosynthesis of Hydroxylated Derivatives of 17 β‐Hydroxy‐5α‐Androstan‐3‐One in Rat Liver Microsomes

The formation of polar, saturated C₁₉steroids with a 3‐keto‐5α‐configuration after incubation of 17β‐hydroxyandrost‐4‐en‐3‐one (testosterone) with 105,000 ×g microsomes of adult male rat liver was investigated. The metabolites were isolated by thin‐layer chromatography and were identified as 2β‐,6β‐(tentatively), 7α‐, and 16α‐hydroxy‐5α‐dihydrotestosterone by means of gas chromatography‐mass spectrometry. The same compounds were also isolated after incubation with 2β‐,6β‐,7α‐, and 16α‐hydroxytestosterone, respectively. Incubation with 5α‐dihydrotestosterone, however, resulted in the formation of 2β‐,7α‐, and 16α‐hydroxy‐5α‐dihydrotestosterone whereas no 6β‐hydroxy‐5α‐dihydrotestosterone could be found.