title: Enantioseparation of novel chiral sulfoxides on chlorinated polysaccharide stationary phases in supercritical fluid chromatography.
abstract: Asymmetric sulfoxides is a particular case of chirality that may be found in natural as well as synthetic products. Twenty-four original molecules containing a sulfur atom as a centre of chirality were analyzed in supercritical fluid chromatography on seven polysaccharide-based chiral stationary phases (CSP) with carbon dioxide - methanol mobile phases. While all the tested CSP provided enantioseparation for a large part of the racemates, chlorinated cellulosic phases proved to be both highly retentive and highly enantioselective towards these species. Favourable structural features were determined by careful comparison of the enantioseparation of the probe molecules. Molecular modelling studies indicate that U-shaped (folded) conformations were most favorable to achieve high enantioresolution on these CSP, while linear (extended) conformations were not so clearly discriminated. For a subset of these species adopting different conformations, a broad range of mobile phase compositions, ranging from 20 to 100% methanol in carbon dioxide, were investigated. While retention decreased continuously in this range, enantioseparation varied in a non-monotonous fashion. Abrupt changes in the tendency curves of retention and selectivity were observed when methanol proportion reaches about 60%, suggesting that a change in the conformation of the analytes and/or chiral selector is occurring at this point.
authors.affiliation: Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans et CNRS, UMR7311, BP 6759, 45067 Orléans, France. Electronic address: caroline.west@univ-orleans.fr.
authors.forename: Caroline
authors.initials: C
authors.lastname: West
authors.affiliation: Institute of Physical and Analytical Chemistry, School of Exact and Natural Sciences, Tbilisi State University, Tbilisi, Georgia.
authors.forename: Mari-Luiza
authors.initials: ML
authors.lastname: Konjaria
authors.affiliation: Institute of Physical and Analytical Chemistry, School of Exact and Natural Sciences, Tbilisi State University, Tbilisi, Georgia.
authors.forename: Natia
authors.initials: N
authors.lastname: Shashviashvili
authors.affiliation: Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans et CNRS, UMR7311, BP 6759, 45067 Orléans, France.
authors.forename: Elise
authors.initials: E
authors.lastname: Lemasson
authors.affiliation: Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans et CNRS, UMR7311, BP 6759, 45067 Orléans, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Bonnet
authors.affiliation: Institut de Chimie Organique et Analytique (ICOA), Université d'Orléans et CNRS, UMR7311, BP 6759, 45067 Orléans, France.
authors.forename: Rusudan
authors.initials: R
authors.lastname: Kakava
authors.affiliation: Department of Chemistry, Materials and Chemical Engineering "G. Natta", Politecnico di Milano, Via Mancinelli 7, 20131, Milan, Italy; CNR Istituto di Chimica del Riconoscimento Moleculare (ICRM), Via Mancinelli 7, 20131 Milan, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Volonterio
authors.affiliation: Institute of Physical and Analytical Chemistry, School of Exact and Natural Sciences, Tbilisi State University, Tbilisi, Georgia.
authors.forename: Bezhan
authors.initials: B
authors.lastname: Chankvetadze
mesh_terms: D002245:Carbon Dioxide / Q000737:chemistry; D025924:Chromatography, Supercritical Fluid / Q000295:instrumentation / Q000379:methods*; D054879:Halogenation; D000432:Methanol / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*; D013237:Stereoisomerism; D013454:Sulfoxides / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D011134:Polysaccharides; D013454:Sulfoxides; D002245:Carbon Dioxide; D000432:Methanol
keywords: Conformation; Enantiomer separation; Molecular modelling; Polysaccharide-based chiral stationary phase; Sulfoxides; Supercritical fluid chromatography