title: Analysis of sterols by high-performance liquid chromatography/mass spectrometry combined with chemometrics.
abstract: A newly developed high-performance liquid chromatography/mass spectrometry (HPLC/MS) method has been successfully used to analyze plasma concentrations of various phytosterols (cholestanol and beta-sitosterol) and cholesterol metabolites (desmosterol and lathosterol). This was based on an unusual solvent combination of water/methanol vs. methanol/acetone/n-hexane applied on a Purospher Star RP-18e (125 x 2 mm, 3 microm) column, which proved excellent for the separation, identification and quantification of plasma sterols. Simple solid-phase extraction preparation of plasma samples was performed, followed by the developed fast and robust HPLC separation. Results on four groups of people were compared, those with low, normal and high plasma cholesterol levels and those with high cholesterol levels on statin therapy, and the results were evaluated using linear discriminant analysis (LDA). Variable selection for LDA was achieved using backward removal selection. Highly discriminatory variables were the ratios of desmosterol to sitosterol and of lathosterol to total plasma cholesterol. The latter ratio was also excellent for distinguishing subjects on statin therapy. The success rate of classification was 100%. The present pilot study shows the potential of HPLC/MS analysis and chemometrics for studying cholesterol-related disorders and warrants future full-scale medical study.
authors.affiliation: Department of Mass Spectrometry, Institute of Structural Chemistry, Chemical Research Center, Hungarian Academy of Sciences, Pusztaszeri ut 59-67, H-1025 Budapest, Hungary.
authors.forename: Kornél
authors.initials: K
authors.lastname: Nagy
authors.forename: Annamaria
authors.initials: A
authors.lastname: Jakab
authors.forename: Ferenc
authors.initials: F
authors.lastname: Pollreisz
authors.forename: David
authors.initials: D
authors.lastname: Bongiorno
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Ceraulo
authors.forename: Maurizio R
authors.initials: MR
authors.lastname: Averna
authors.forename: Davide
authors.initials: D
authors.lastname: Noto
authors.forename: Károly
authors.initials: K
authors.lastname: Vékey
mesh_terms: D004083:Cholestanol / Q000097:blood; D002784:Cholesterol / Q000097:blood; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003897:Desmosterol / Q000097:blood; D016002:Discriminant Analysis; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D006937:Hypercholesterolemia / Q000097:blood / Q000188:drug therapy; D013058:Mass Spectrometry / Q000379:methods*; D010865:Pilot Projects; D012855:Sitosterols / Q000097:blood; D013261:Sterols / Q000097:blood*
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D012855:Sitosterols; D013261:Sterols; D003897:Desmosterol; C025473:gamma-sitosterol; C001521:lathosterol; D004083:Cholestanol; D002784:Cholesterol