STEROL SYNTHESIS - A TIMELY LOOK AT THE CAPABILITIES OF CONVENTIONAL AND SILVER ION HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY FOR THE SEPARATION OF C-27 STEROLS RELATED TO CHOLESTEROL-BIOSYNTHESIS

Sterol intermediates in the biosynthesis of cholesterol have recently assumed a very prominent position in a number of important problems in medicine and biology. In studies of these matters, the separation and identification of the sterol intermediates present formidable challen ges, a situation which does not appear to be generally appreciated. Hi gh performance liquid chromatography (HPLC) is a simple and rapid appr oach for the separation of the concerned compounds. Reversed phase HPL C is very commonly used for this purpose. In the present studies, we h ave evaluated the capabilities of reversed phase, normal phase, and si lver ion HPLC for the separation of sterols. Using an extensive collec tion of authentic sterols, our studies indicate very limited capabilit ies of reversed phase and normal phase HPLC for the separation of C-27 sterols differing in the number and location of olefinic double bonds . In contrast, silver ion HPLC provided remarkable separations of the same compounds, either as the free sterols or their acetate derivative s. These findings, coupled with the results of recent studies of the p roperties of the same compounds by gas chromatography and by nuclear m agnetic resonance and mass spectroscopy, have important implications r egarding current application of methodologies for the separation, iden tification, and quantitation of sterol intermediates in cholesterol bi osynthesis as critical portions of investigations on a number of curre nt and emerging problems in biology and medicine.