title: Enantiomeric separation of bicyclo[2.2.2]octane-based 2-amino-3-carboxylic acids on macrocyclic glycopeptide chiral stationary phases.
abstract: Direct high-performance liquid chromatographic (HPLC) separation of four bicyclo[2.2.2]octane based 2-amino-3-carboxylic acid enantiomers were developed on chiral stationary phases (CSPs) containing different macrocyclic glycopeptide antibiotic selectors. The analyses were performed under reversed-phase, polar organic and polar ionic mode on macrocyclic-glycopeptide-based Chirobiotic T, T2, TAG, and R columns. The effects of the mobile phase composition including the acid and base modifier, the structure of the analytes, and the temperature on the separations were investigated. Experiments were achieved at constant mobile phase compositions on different stationary phases in the temperature range 5-40°C. Thermodynamic parameters were calculated from plots of ln k or ln α versus 1/T. It was recognized that the enantioseparations in reversed-phase and polar organic mode were enthalpically driven, but under polar-ionic conditions entropically driven enantioseparation was observed as well. Baseline separation and determination of elution sequence were achieved in all cases.
authors.affiliation: Department of Inorganic and Analytical Chemistry, University of Szeged, Szeged, Hungary.
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Pataj
authors.forename: István
authors.initials: I
authors.lastname: Ilisz
authors.forename: Nóra
authors.initials: N
authors.lastname: Grecsó
authors.forename: Márta
authors.initials: M
authors.lastname: Palkó
authors.forename: Ferenc
authors.initials: F
authors.lastname: Fülöp
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Armstrong
authors.forename: Antal
authors.initials: A
authors.lastname: Péter
mesh_terms: D001643:Bridged Bicyclo Compounds / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry* / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D019277:Entropy; D006020:Glycopeptides / Q000737:chemistry; D047028:Macrocyclic Compounds / Q000737:chemistry; D013237:Stereoisomerism; D013696:Temperature; D013816:Thermodynamics
chemical_list: D001643:Bridged Bicyclo Compounds; D002264:Carboxylic Acids; D006020:Glycopeptides; D047028:Macrocyclic Compounds; C000597575:chirobiotic T
keywords: column liquid chromatography; enantiomer separation; macrocyclic glycopeptide-based columns; β-amino acid analogs