title: The influence of the substituent position in monocarboxymethyl-γ-cyclodextrins on enantioselectivity in capillary electrophoresis.
abstract: Three newly synthesized chiral selectors, namely, 2(I)-O-, 3(I)-O-, and 6(I)-O-carboxymethyl-γ-cyclodextrin, native γ-cyclodextrin, and commercially available carboxymethylated γ-cyclodextrin with degree of substitution of 3-6 were used as additives in a background electrolyte composed of phosphate buffer at 20 mmol/L concentration and pH 2.5. This system was used for the analysis of several biologically significant low-molecular-mass chiral compounds by capillary electrophoresis. The results confirmed that the position of carboxymethyl group influences the enantioseparation efficiency of all the studied analytes. The 2(I)-O- and 3(I)-O- regioisomers provide a significantly better resolution than native γ-cyclodextrin, while the 6(I)-O-regioisomer gives only a slightly better enantioseparation than native γ-cyclodextrin. The application of γ-cyclodextrin possessing higher number of carboxymethyl groups led to the best resolution for the majority of the compounds analyzed.
authors.affiliation: Department of Analytical Chemistry, Institute of Chemical Technology, Prague, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Rezanka
authors.forename: Lenka
authors.initials: L
authors.lastname: Rokosová
authors.forename: Klára
authors.initials: K
authors.lastname: Rezanková
authors.forename: Markéta
authors.initials: M
authors.lastname: Bláhová
authors.forename: Michal
authors.initials: M
authors.lastname: Rezanka
authors.forename: David
authors.initials: D
authors.lastname: Sýkora
authors.forename: Jindřich
authors.initials: J
authors.lastname: Jindřich
authors.forename: Vladimír
authors.initials: V
authors.lastname: Král
keywords: Capillary electrophoresis; Chiral separation; Enantioselectivity; Regioisomers; Substituted cyclodextrins