The introduction of the C-22-C-23 ethylenic linkage in ergosterol biosynthesis.
Methods for the chemical synthesis of [23-(3)H(2)]lanosterol, [23,25-(3)H(3)]24-methyldihydrolanosterol and [24,28-(3)H(2)]24-methyldihydrolanosterol are described. It is shown that, in the biosynthesis of ergosterol from [26,27-(14)C(2),23-(3)H(2)]lanosterol by the whole cells of Saccharomyces cerevisiae, one of the original C-23 hydrogen atoms is lost and the other is retained at C-23 of ergosterol. It is also shown that 24-methyldihydrolanosterol is converted into ergosterol in good yield and without prior conversion into a 24-methylene derivative. On the basis of these results possible pathways for the formation of the ergosterol side chain from a 24-methylene side chain are discussed.
D002247:Carbon Isotopes; D002855:Chromatography, Thin Layer; D007259:Infrared Rays; D009682:Magnetic Resonance Spectroscopy; D012440:Saccharomyces / Q000378:metabolism*; D013057:Spectrum Analysis; D013261:Sterols / Q000378:metabolism*; D014316:Tritium; D014807:Vitamin D / Q000096:biosynthesis*
D002247:Carbon Isotopes; D013261:Sterols; D014316:Tritium; D014807:Vitamin D