Analytical and preparative chiral separation of β-carboline derivatives, LDL oxidation inhibitors, using HPLC and CE methodologies: Determination of enantiomeric purity

摘要

In the present study, baseline separation of the enantiomers of 16 β-carboline derivatives was successfully achieved using both capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) techniques in short run times (≥15 min) and thus permit the determination of enantiomeric excess. In HPLC methodology, cellulose chiral stationary phase (Chiralcel OD-H) was used with a binary mobile phase constituted of n-hexane/ethanol 85/15 leading to a resolution factor of 12.6 in 15 min. Preparative HPLC allowed to obtain pure enantiomers of two compounds. In CE, chiral selectivity was developed with an in-capillary stacking strategy using anionic (highly sulfated-γ) cyclodextrins 5% (w/v) as chiral selectors and a 60 mM phosphate buffer (pH 2.5) resulting in a resolution of 10.26 in 14 min of analysis. The analytical characteristics of the two developed methods were studied in terms of repeatability, limits of detection and limits of quantification showing their suitability to be extended to all the other molecules.