Mayo K. Walden

High-pressure liquid chromatography of steroidal alkaloids.

High-pressure liquid chromatography was used to separate the following steroidal alkaloids: tomatidine, solanidine, solasodine, rubijervine, veratramine and jervine. The method was used to prepare crystalline solanidine from a crude mixture of aglycones obtained from Solanum chacoense, and to separate radioactive solanidine from extracts of potato plants fed with [4-C]cholesterol.

Liquid column chromatography of free sterols

Abstract Liquid column chromatography with an apolar sorbent—eluent system permits the separation of free sterols differing in the number and position of double bonds and in their alkyl side chains. The method is applicable tothe isolation of minute quantities of sterols from a large excess of closely related sterols.

Determination of Solasodine in Fruits of Solanum Khasianum by a Combination of Chromatofuge and High-Pressure Liquid Chromatography

Abstract An extract of Solanum khasianum fruits was fractionated with a chromatofuge. The fraction containing solasodine was applied to a HPLC column and the effluent was monitored by UV. The peak height gave an accurate measure of the amount present. The efficiency and load capacity of the chromatofuge, as well as the accuracy and precision of the HPLC method were determined.

High-pressure liquid chromatography and ultraviolet spectrometry of ketonic C27 sterols

A method for the separation of ketonic C27 sterols was devised, based on high-pressure liquid chromatography (HPLC) and ultraviolet absorption (UV). The adsorption column contained silica gel, particle size 10 μm, and the eluents were dichloromethane/n-hexane/ethyl acetate (94∶5∶1) and dichloromethane/ethyl actate (99∶1) followed by dichloromethane/ethyl acetate (3∶1). The 5β-sterols were eluted before the 5α-analogs, sterols with isolated double bonds before conjugated carbonyl compounds, and ketones before hydroxy ketones. The effect of carbonyl groups on polarity depends on the position in the molecule and decreases in the order C-3>C-6>C-7. The ultraviolet absorption spectra of eleven sterols were determined, and their absorbance at 254 nm and at 280 nm was used for analyzing the column effluent with a dual detector system.