Karuna, Ratnaningrum, Christen, Isabelle, Sailer, Andreas, Bitsch, Francis and Zhang, Juan (2014) Detection of dihydroxycholesterols in human plasma using HPLC-ESI-MS/MS. Steroids.

Abstract

We report a straightforward sample preparation procedure and a direct liquid chromatography electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) method for the analysis of 7alpha,25-dihydroxycholesterol (725-OHC) and 7alpha,27-dihydroxycholesterol or (727-OHC). By applying a slow protein precipitation approach using cold ethanol, we were able to detect and quantify 725-OHC and 727-OHC in a fast and reliable manner. The average concentrations from 20 healthy individuals were determined to be 0.21 ± 0.05 nM for 725-OHC and 3.4 ± 0.1 nM for 727-OHC. In addition, we are the first to report the average degrees of esterification (n=8) to be 73.8% and 82% for 725-OHC and 727-OHC, respectively. Using the established method, we achieved the sensitivity sufficient for detecting low abundant dihydroxylated oxysterols in healthy individuals. This result should enable extension of these studies towards a comprehensive analysis of oxysterol levels under disease conditions.

Item Type:	Article
Keywords:	Oxysterols, hydroxycholesterol, dihydroxycholesterols, liquid chromatography, electrospray ionization, mass spectrometry, human plasma, G protein-coupled receptor, Epstein-Barr virus-induced gene 2, 7 alpha, 25-dihydroxycholesterol, 7 alpha, 27-dihydroxycholesterol
Date Deposited:	13 Oct 2015 13:11
Last Modified:	13 Oct 2015 13:11
URI:	https://oak.novartis.com/id/eprint/24362