Steroids in Germfree and Conventional Rats: 7. Identification of C₁₉ and C₂₁ Steroids in Faeces from Conventional Rats

Gas chromatography‐mass spectrometry has been used to identify nine C₁₉ and six C₂₁ steroids in faeces from conventional rats. The compounds characterized were: 3β‐hydroxyandrost‐5‐en‐17‐one; 3α,11β‐dihydroxy‐ and 3α,7α‐dihydroxy‐5α‐androstan‐17‐one; 5α‐androstane‐3α,7α,17β‐triol; 5α‐androstane‐3α,15α,17β‐triol; 3α(and 3β),19‐dihydroxy‐5α‐androstan‐17‐one; 5α‐androstane‐3α(and 3β),17β‐diol; 3α(and 3β),16α‐dihydroxy‐5α‐pregnan‐20‐one; 3α(and 3β),15α‐dihydroxy‐5α‐pregnan‐20‐one and 3α(and 3β),19‐dihydroxy‐5α‐pregnan‐20‐one. Their chromatographic behaviour and ready solvolysis in ethyl acetate acidified with sulphuric acid indicate that the steroids were present in faeces as monosulphates. These findings are discussed in relation to the results obtained from analyses of steroids in faeces from germfree rats.