High Performance Liquid Chromatography of Molecular Species from Free Sterols and Sterylglycosides Isolated from Oat Leaves and Seeds1

Abstract

Free steroli and sterylglycosides (SG) from oat leaves and seeds were isolated by conventional thin layer chromatography (TLC) and subjected to high performance liquid chromatography (HPLC) for resolution of molecular species. Acylsterylglycolides, isolated by TLC, were converted to SG by mild alkaline hydrolysis and determined as SG. Sterols and SG were injected onto the column without any chemical treatment and the separated species were detected at 200 nm. The separation of SG-species follows exactly the separation of free sterols.Though gas liquid chromatography still is the method of choice, advantages of HPLC is to analyse directly the SG-specia without hydrolysis and derivatization as compared to GLC. After TLC the sterol-and the SG-fraction are injected directly onto the column. This is extremely important for labile sterylglycosides or sterols, as demonstrated for the avenasterols.

Analysis of phytosterols in foods

“…Indeed, saturated sterols, with no double bond in the ring structure, exhibited low response factors (0.25-0.31), whereas unsaturated sterols with one double bond in the ring structure had high response factors (0.89-1.42). Further differences observed within free sterol response factors could be explained by differences in the sterol side chains [94].…”

“…RP-HPLC in combination with UV or light scattering detection has been shown to be useful for the analysis of molecular species of steryl glycosides and acylated steryl glycosides [93,94]. Prior to LC separation, TLC was applied for sample clean up and for the separation of different steryl species.…”

“…The acylated species (steryl esters and acylated steryl glycosides) were converted to the corresponding non-acetylated species (free sterols and steryl glycosides) by alkaline hydrolysis. Using HPLC in combination with UV detection (200 nm), free sterol standards can be used to quantify steryl glycosides, since at low wavelengths the glycosidic residues do not affect the UV absorption properties of steryl glycosides [94].…”

Plasma Membrane Lipids Associated with Genetic Variability in Freezing Tolerance and Cold Acclimation of Solanum Species

“…Cerebroside and SG were separated on a 15-cm X 4.6-mm i.d. C6 reversed-phase column with 5-pm Spherisorb packing (Chromanetics, Malaga, NY) by elution with a linear gradient of acetonitrile and water ranging from 55 to 80% acetonitrile, delivered at 1.0 mL min-' (Kesselmeier et al, 1985;Whitaker et al, 1990). Sterol composition of ASG and SG was determined by hydrolyzing the steryl glycoside with 2 N TFA in dioxane:water (l:l, v/v), precipitating the liberated sterols with digitonin after hexane extraction, and analyzing the FS by GLC (Whitaker and Lusby, 1989).…”

Measurement of Sterylglycosides by High Performance Liquid Chromatography with 1-Anthroylnitrile Derivatives

“…Many publications 1 -8) have dealt with sterylglycoside analysis, however, only a few of them 7,8) have appeared in the last decade dealing with HPLC analysis of these glycosides. In spite of the good trials in measuring these components by HPLC, there were some problems that were encountered with sensitivity in detection and preciseness of the results.…”