title: Chiral separation of the clinically important compounds fucose and pipecolic acid using CE: determination of the most effective chiral selector.
abstract: In this study, simple electrophoretic methods were developed for the chiral separation of the clinically important compounds fucose and pipecolic acid. In recent years, these analytes, and particularly their individual enantiomers, have attracted considerable attention due to their role in biological functions and disorders. The detectability and sensitivity of pipecolic acid and fucose were improved by reacting them with fluorenylmethyloxycarbonyl chloride (FMOC-Cl) and 5-amino-2-naphthalene-sulfonic acid (ANSA), respectively. The enantioseparation conditions were optimized by initially investigating the type of the chiral selector. Different chiral selectors, such as polymeric surfactants and cyclodextrins, were used and the most effective ones were determined with regard to resolution and analysis time. A 10-mM β-cyclodextrin was able to separate the enantiomers of ANSA-DL-fucose and the polymeric surfactant poly(sodium N-undecanoyl-LL-leucine-valinate) was able to separate the enantiomers of FMOC-DL-pipecolic acid, with resolution values of 3.45 and 2.78, respectively. Additional parameters, such as the concentration and the pH of the background electrolyte (BGE), the concentration of the chiral selector, and the addition of modifiers were examined in order to optimize the separations. The addition of the chiral ionic liquid D-alanine tert-butyl ester lactate into the BGE was also investigated, for the first time, in order to improve resolution of the enantiomers.
authors.affiliation: Department of Chemistry, University of Cyprus, Nicosia, Cyprus.
authors.forename: Christoforos A
authors.initials: CA
authors.lastname: Hadjistasi
authors.forename: Ioannis J
authors.initials: IJ
authors.lastname: Stavrou
authors.forename: Raluca-Ioana
authors.initials: RI
authors.lastname: Stefan-Van Staden
authors.forename: Hassan Y
authors.initials: HY
authors.lastname: Aboul-Enein
authors.forename: Constantina P
authors.initials: CP
authors.lastname: Kapnissi-Christodoulou
mesh_terms: D019075:Electrophoresis, Capillary; D005643:Fucose / Q000737:chemistry*; D052578:Ionic Liquids / Q000737:chemistry; D010875:Pipecolic Acids / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D052578:Ionic Liquids; D010875:Pipecolic Acids; D005643:Fucose; C031345:pipecolic acid
keywords: capillary electrophoresis; enantioseparation; fucose; ionic liquids; pipecolic acid