title: High-performance liquid chromatographic enantioseparation of monoterpene-based 2-amino carboxylic acids on macrocyclic glycopeptide-based phases.
abstract: The enantiomers of five monoterpene-based 2-amino carboxylic acids were directly separated on chiral stationary phases containing macrocyclic glycopeptide antibiotics such as teicoplanin (Astec Chirobiotic T and T2) and teicoplanin aglycone (Chirobiotic TAG) as chiral selectors. The effects of pH, the mobile phase composition, the structure of the analyte and temperature on the separations were investigated. Experiments were performed at constant mobile phase compositions in the temperature range 10-40°C to study the effects of temperature and thermodynamic parameters on separations. Apparent thermodynamic parameters and T(iso) values were calculated from plots of ln k or ln α versus 1/T. Some mechanistic aspects of the chiral recognition process are discussed with respect to the structures of the analytes. It was found that the enantioseparations were in most cases enthalpy driven. The sequence of elution of the enantiomers was determined in all cases.
authors.affiliation: Institute of Pharmaceutical Chemistry, University of Szeged, Eötvös utca 6, H-6720 Szeged, Hungary.
authors.forename: László
authors.initials: L
authors.lastname: Sipos
authors.forename: István
authors.initials: I
authors.lastname: Ilisz
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Pataj
authors.forename: Zsolt
authors.initials: Z
authors.lastname: Szakonyi
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: D002264:Carboxylic Acids / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006020:Glycopeptides / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D047028:Macrocyclic Compounds / Q000737:chemistry*; D039821:Monoterpenes / Q000737:chemistry*; D013237:Stereoisomerism; D013816:Thermodynamics
chemical_list: D002264:Carboxylic Acids; D006020:Glycopeptides; D047028:Macrocyclic Compounds; D039821:Monoterpenes