title: Synthesis of delta 5,22-cholestadien-3 beta-ol from delta 5,7,22-cholestatrien-3 beta-ol by a liver enzyme.
abstract: The rat liver enzyme system, which catalyzes reduction of delta 5,7,24-cholestatrien-3 beta-ol to cholesterol (delta 5-cholesten-3 beta-ol), converted radiolabeled delta 5,7,22-cholestatrien-3 beta-ol to delta 5,22-cholestadien-3 beta-ol, but not to cholesterol. This enzyme system thus contains membrane-bound delta 7- and delta 24-reductase and no delta 22-reductase. Kinetic and competition studies showed that the enzyme system contains a single delta 5,7-sterol delta 7-reductase, which is not influenced by unsaturation at the delta 22-position of the sterol side chain. The identity of delta 5,22-cholestadienol was established by chromatographic, spectral and chemical analyses. Use of the enzyme system and readily available delta 5,7,22-cholestatrienol provides a facile procedure for specific production of delta 5,22-cholestadien-3 beta-ol in quantity.
mesh_terms: D000818:Animals; D002775:Cholestadienols / Q000378:metabolism*; D002782:Cholestenes / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D003684:Dehydrocholesterols / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000201:enzymology*; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D010088:Oxidoreductases / Q000378:metabolism; D044925:Oxidoreductases Acting on CH-CH Group Donors; D051381:Rats; D013261:Sterols / Q000378:metabolism; D001371:trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride / Q000494:pharmacology
chemical_list: D002775:Cholestadienols; D002782:Cholestenes; D003684:Dehydrocholesterols; D013261:Sterols; C033144:lathosterol delta-5-dehydrogenase; D009243:NAD; C032844:5,7,22-cholestatrien-3beta-ol; C032843:5,22-cholestadien-3beta-ol; D001371:trans-1,4-Bis(2-chlorobenzaminomethyl)cyclohexane Dihydrochloride; D009249:NADP; D010088:Oxidoreductases; D044925:Oxidoreductases Acting on CH-CH Group Donors; C022673:delta 24-sterol reductase