title: Sterol biosynthesis by the sea urchin Echinus esculentus.
abstract: 1. The 4-demethyl sterols of Echinus esculentus consisted of cholesterol as the major component, with lower concentrations of nine other C(26), C(27), C(28) and C(29) Delta(5) sterols. 2. [2-(14)C]Mevalonic acid was readily incorporated by the urchin into squalene, lanosterol and desmosterol but only to a small extent into cholesterol. 3. [26-(14)C]Desmosterol did not appear to be reduced to give cholesterol, but conversion of 5alpha-[2-(3)H(2)]lanost-8-en-3beta-ol into cholesterol was observed. 4. No C-24 dealkylation of [4-(14)C]sitosterol or metabolism of [4-(14)C]cholesterol could be detected.
mesh_terms: D000818:Animals; D001345:Autoradiography; D002250:Carbon Radioisotopes; D002784:Cholesterol / Q000096:biosynthesis / Q000378:metabolism; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D003897:Desmosterol / Q000096:biosynthesis; D007810:Lanosterol / Q000096:biosynthesis; D013058:Mass Spectrometry; D008798:Mevalonic Acid / Q000378:metabolism; D012617:Sea Urchins / Q000378:metabolism*; D013185:Squalene / Q000096:biosynthesis; D013261:Sterols / Q000096:biosynthesis*; D014316:Tritium
chemical_list: D002250:Carbon Radioisotopes; D013261:Sterols; D014316:Tritium; D007810:Lanosterol; D003897:Desmosterol; D013185:Squalene; D002784:Cholesterol; D008798:Mevalonic Acid