Steroids in Germfree and Conventional Rats: 5. Identification of C₁₉ Steroids in Faeces from Germfree Rats

The C₁₉ steroids in faeces from germfree rats have been studied by gas chromatography‐mass spectrometry. 3α,11β‐Dihydroxy‐5α‐androstan‐17‐one and 3α,7α‐dihydroxy‐5α‐androstan‐17‐one were the predominant steroids in this group and 5α‐androstane‐3α,7α,17β‐triol, 3α,19‐dihydroxy‐5α‐androstan‐17‐one were also identified. Evidence was obtained for the presence of 3α,15α‐dihydroxy‐5α‐androstan‐17‐one, 5α‐androstane‐3α,15α,17β‐triol and 5α‐androstane‐3α,17β‐diol. The latter compounds were present in small amounts and their stereochemistry could not be definitely established. The steroids were present in faeces as monosulphates as evidenced by their chromatographic behaviour on Sephadex LH‐20 and carboxymethyl Sephadex LH‐20. The possible significance of the predominance of 3α,5α steroid isomers in faeces from germfree rats is discussed.