title: Side-chain cleavage of C27-3-oxo-4-ene sterols.
abstract: In this study various C27 sterols with a 3-oxo-4-ene structure were incubated with adrenal cortex mitochondrial preparations. (22R)-22-Hydroxy-4-cholesten-3-one and (20R,22R)-20,22-dihydroxy-4-cholesten-3-one were found to be converted into progesterone. This suggests the existence of a pathway for adrenal progesterone formation analogous to the normal 3 beta-hydroxy-5-ene pathways. (20S)-20-Hydroxy-4-cholesten-3-one was hydroxylated at C25. 4-Cholesten-3-one, 25-hydroxy-4-cholesten-3-one and (22S)-22-hydroxy-4-cholesten-3-one were not converted to a measurable extent. With 3-oxo-4-ene C27 sterols as substrates, the cholesterol side-chain cleaving enzyme system seems to require the presence of a 22R-hydroxyl group in the substrate. The clinical relevance of these observations is discussed.
mesh_terms: D000302:Adrenal Cortex / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D002782:Cholestenes / Q000378:metabolism*; D002783:Cholestenones / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D008401:Gas Chromatography-Mass Spectrometry; D008928:Mitochondria / Q000378:metabolism*; D011374:Progesterone / Q000096:biosynthesis; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
chemical_list: D002782:Cholestenes; D002783:Cholestenones; D011374:Progesterone