The role of a cholesta-8,14-dien-3-beta-ol system in cholesterol biosynthesis.
The biosynthesis of cholesterol from squalene and tritiated water is described. Degradation of the cholesterol indicated that C-15 may be involved in cholesterol biosynthesis. In accordance with this view it is shown that in the conversion of [2RS-(3)H(2)]mevalonic acid into cholesterol one of the hydrogen atoms at C-15 is removed. A mechanism for the removal of the 14alpha-methyl group in steroid biosynthesis that involves the labilization of a C-15 hydrogen atom is outlined. In accordance with the requirement of this scheme it is shown that 4,4'-dimethyl-cholesta-8,14-dien-3beta-ol is converted into cholesterol.
D000818:Animals; D002776:Cholestanes / Q000378:metabolism*; D002784:Cholesterol / Q000096:biosynthesis*; D006859:Hydrogen; D066298:In Vitro Techniques; D007930:Leucine / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008745:Methylation; D008798:Mevalonic Acid / Q000378:metabolism; D051381:Rats; D013185:Squalene / Q000378:metabolism; D013261:Sterols / Q000378:metabolism*; D014316:Tritium; D014867:Water / Q000378:metabolism
D002776:Cholestanes; D013261:Sterols; D014867:Water; D014316:Tritium; D013185:Squalene; D006859:Hydrogen; D002784:Cholesterol; D007930:Leucine; D008798:Mevalonic Acid