Gas-Liquid Chromatography of Sterol Methyl Ethers and Some Correlations Between Molecular Structure and Retention Data^*

Abstract

A simple method for the conversion of sterols to their methyl ethers in high yield has been developed and has been shown to be applicable to representatives of all the commonly encountered classes of 3-hydroxysterols. The behavior of the sterol ethers on gas-liquid chromatography with polydiethylene glycol succinate as the liquid phase has been shown to permit the separation of many compounds of biological importance. It has been shown that the influence of substituents and other structural modifications on the retention times of these and related steroids may be described in a simple mathematical form. This finding is discussed in the light of other published work.

Azasterol inhibition of .DELTA.24-sterol methyltransferase in Saccharomyces cerevisiae

“…The Rf values and composition of the bands on a developed plate are as follows: 0.2-0.3, A5,7-dienes; 0.35-0.46, desmethylsterols; 0.47-0.51, 4amethylsterols; 0.52-0.56, 4,4-dimethylsterols; 0.60-0.67, squalene. The bands were removed and thoroughly extracted with ether. Each fraction was dried to constant weight and taken up in chloroform (1-2 mL), and aliquots of the solution were transferred to microsample tubes (Clayton, 1962) [(25-30) X 6 mm] containing 0.1 mg of cholestanol. Solvent was removed under a N2 stream.…”

Silver ion high pressure liquid chromatography provides unprecedented separation of sterols: application to the enzymatic formation of cholesta-5,8-dien-3 beta-ol.

“…However, GC alone is limited by the close similarity of retention times of many sterols differing only in the location of olefinic double bonds (49)(50)(51).…”

Effects of triarimol and tridemorph on sterol biosynthesis inSaprolegnia ferax

“…A comparison was made between the relative retention times of various sterol standards to determine the effects of position of double bond and alkyl substituents on relative retention time. Three different gas chromatographic columns were Table 2, and Table 3 shows the calculated RRT's of possible sterol structures based on GLC-MS data, according to previously published methods (26,30). These calculated RRT's were then compared with the actual RRT of the sample and a positive identification was made in each case.…”