Investigations on the biosynthesis of steroids and terpenoids. Part VI. The sterols of yeast

Abstract

All the detectable sterols of yeast (Saccharomyces cerevisiae) with polarities (as measured by their R_F values on silica gel)⩽ ergosta-5,7,22,24(28)-teraen-3β-ol have been isolated and characterised. In addition to the known fully defined sterols, lanosterol. 14-demethyl-lanosterol, 4α-methylzymosterol, 24,25-dihydro-4α-methyl-24-methylenezymosterol, zymosterol,5,6-dihydroergosterol, ergosta-5,7,22,24(28)-tetraen-3β-ol, and ergosterol, the less well characterised sterols, fecosterol and episterol, have been reisolated and the structures confirmed. Sterols previously unreported in yeast, parkeol, ergost-7-en-3β-ol, ergosta-7,22,24(28)-trien-3β-ol, and ergosta-5,7,24(28)-trien-3β-ol have also been isolated and characterised. Ascosterol has been shown to be a mixture.