title: High-performance liquid chromatographic enantioseparation of unusual isoxazoline-fused 2-aminocyclopentanecarboxylic acids on macrocyclic glycopeptide-based chiral stationary phases.
abstract: The enantiomers of four unusual isoxazoline-fused 2-aminocyclopentanecarboxylic acids were directly separated on chiral stationary phases containing macrocyclic glycopeptide antibiotics teicoplanin (Astec Chirobiotic T and T2), teicoplanin aglycone (Chirobiotic TAG), vancomycin (Chirobiotic V) and vancomycin aglycone (Chirobiotic VAG) as chiral selectors. The effects of the mobile phase composition, the structure of the analytes and temperature on the separations were investigated. Experiments were performed at constant mobile phase compositions in the temperature range 5-45 °C to study the effects of temperature, and thermodynamic parameters were calculated from plots of lnk or lnα 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 enantiomeric separations 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: Melinda
authors.initials: M
authors.lastname: Nonn
authors.forename: Ferenc
authors.initials: F
authors.lastname: Fülöp
authors.forename: Zoltán
authors.initials: Z
authors.lastname: Pataj
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Armstrong
authors.forename: Antal
authors.initials: A
authors.lastname: Péter
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D003515:Cycloleucine / Q000737:chemistry / Q000302:isolation & purification*; D007555:Isoxazoles / Q000737:chemistry / Q000302:isolation & purification*; D016014:Linear Models; D013237:Stereoisomerism; D017334:Teicoplanin / Q000031:analogs & derivatives* / Q000737:chemistry; D013816:Thermodynamics; D014640:Vancomycin / Q000737:chemistry*
chemical_list: D007555:Isoxazoles; D003515:Cycloleucine; D017334:Teicoplanin; D014640:Vancomycin