title: Metabolism of unsaturated bile acids and androstanes by human faecal bacteria.
abstract: The metabolism of unsaturated bile acids and androstanes by mixed human faecal cultures has been studied. The reactions observed were mainly reductive. Unsaturated 4-ene-3-oxo and 1,4-diene-3-oxo bile acids were reduced in Ring A. 5 beta-3-Oxo bile acids were reduced to 5 beta-3-hydroxy bile acids. 4-Ene, 1,4-diene and 4,6-diene-3,17-dioxo-androstanes were reduced in Ring A with concomitant reduction of oxo groups to hydroxyl groups. The Gram-negative facultative anaerobic faecal bacteria are implicated in the reductive process, whilst the genus Clostridium does not appear to be important. Inclusion of menadione, a synthetic form of vitamin K, retards the reductive process.
mesh_terms: D000730:Androstadienes / Q000378:metabolism; D000731:Androstanes / Q000378:metabolism*; D000735:Androstenedione / Q000031:analogs & derivatives / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D001647:Bile Acids and Salts / Q000378:metabolism*; D003840:Deoxycholic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D005243:Feces / Q000382:microbiology*; D006801:Humans; D008095:Lithocholic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D010084:Oxidation-Reduction; D011245:Pregnadienes / Q000378:metabolism; D014812:Vitamin K / Q000494:pharmacology
chemical_list: D000730:Androstadienes; D000731:Androstanes; D001647:Bile Acids and Salts; D011245:Pregnadienes; D003840:Deoxycholic Acid; D014812:Vitamin K; C046232:3-oxochol-4-en-24-oic acid; C046233:12-hydroxyandrosta-1,4-diene-3,17-dione; C046231:dehydrodeoxycholic acid; D000735:Androstenedione; D008095:Lithocholic Acid; C038796:4,6-androstadiene-3,17-dione; C046234:12-hydroxy-3-oxo-1,4-pregnadiene-20-carboxylic acid; C046230:3-oxocholan-24-oic acid