| Literature DB >> 25683891 |
Ratna Karuna1, Isabelle Christen2, Andreas W Sailer3, Francis Bitsch2, Juan Zhang4.
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 (7α25-OHC) and 7alpha,27-dihydroxycholesterol (7α27-OHC). By applying a slow protein precipitation approach using cold ethanol, we were able to detect and quantify 7α25-OHC and 7α27-OHC in a fast and reliable manner. The average concentrations from 20 healthy individuals were determined to be 0.21±0.05nM for 7α25-OHC and 3.4±0.1nM for 7α27-OHC. In addition, we are the first to report the average degrees of esterification (n=8) to be 73.8% and 82% for 7α25-OHC and 7α27-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.Entities:
Keywords: 7alpha,25-dihydroxycholesterol; 7alpha,27-dihydroxycholesterol or 7alpha,(25R)26-dihydroxycholesterol; G protein-coupled receptor; Hydroxycholesterol; Mass spectrometry; Oxysterols
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Year: 2015 PMID： 25683891 DOI： 10.1016/j.steroids.2015.02.002
Source DB: PubMed Journal: Steroids ISSN： 0039-128X Impact factor: 2.668