Abstract
An evaluation was made of the stability of cholesterol hydroperoxides (CHPs) under the analytical conditions and preparation methods commonly used for determination and quantification of cholesterol oxidation products (COPs). CHPs were prepared by photoxidation and separated by silica thin-layer chromatography. CHPs were individually collected by normal-phase liquid chromatography and then subjected either to reduction or to cold saponification. The corresponding hydroxyl derivatives were generated by reduction, whereas cold saponification gave rise predominantly to 7-ketocholesterol. In another test, silylated and non-silylated CHPs were separately injected into a gas chromatograph at 310 degrees C, collected, and re-injected into a gas chromatography-mass spectrometry system. The silylated CHPs were more stable than the non-silylated ones, giving 7-ketocholesterol, 7alpha- and 7beta-hydroxycholesterol as main degradation products. Two unknown degradation peaks were detected in both silylated and nonsilylated CHPs, having 384 as main m/z fragment. The study of their mass spectra led to the conclusion that peaks A and B correspond to 6alpha- and 6beta-hydroxycholesterol, respectively.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
