Volume 42, Issue 17-18 p. 1853-1863
Research Article

Enantioseparations of polyhalogenated 4,4’-bipyridines on polysaccharide-based chiral stationary phases and molecular dynamics simulations of selector–selectand interactions

Roberto Dallocchio

Roberto Dallocchio

Istituto di Chimica Biomolecolare ICB CNR, Sede secondaria di Sassari, Sassari, Italy

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Barbara Sechi

Barbara Sechi

Istituto di Chimica Biomolecolare ICB CNR, Sede secondaria di Sassari, Sassari, Italy

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Alessandro Dessì

Alessandro Dessì

Istituto di Chimica Biomolecolare ICB CNR, Sede secondaria di Sassari, Sassari, Italy

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Bezhan Chankvetadze

Bezhan Chankvetadze

School of Exact and Natural Sciences, Institute of Physical and Analytical Chemistry, Tbilisi State University, Tbilisi, Georgia

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Sergio Cossu

Sergio Cossu

Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, Mestre, Venezia, Italy

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Victor Mamane

Victor Mamane

Institut de Chimie de Strasbourg, UMR 7177, CNRS-Université de Strasbourg, Strasbourg, France

Additional corresponding author: Dr. Victor Mamane, Institut de Chimie de Strasbourg, Centre National de la Recherche Scientifique and Université de Strasbourg, 1 rue Blaise Pascal, 67008 Strasbourg Cedex, France

E-mail: [email protected]

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Robin Weiss

Robin Weiss

Institut de Chimie de Strasbourg, UMR 7177, CNRS-Université de Strasbourg, Strasbourg, France

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Patrick Pale

Patrick Pale

Institut de Chimie de Strasbourg, UMR 7177, CNRS-Université de Strasbourg, Strasbourg, France

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Paola Peluso

Corresponding Author

Paola Peluso

Istituto di Chimica Biomolecolare ICB CNR, Sede secondaria di Sassari, Sassari, Italy

Correspondence: Dr. Paola Peluso, Istituto di Chimica Biomolecolare, Consiglio Nazionale delle Ricerche, Traversa La Crucca 3, Li Punti, 07100 Sassari, Italy

E-mail: [email protected]

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First published: 20 March 2021
Citations: 8

Color online: See article online to view Figs. 1–3 and 6 in color.

Abstract

2’-(4-Pyridyl)- and 2’-(4-hydroxyphenyl)-TCIBPs (TCIBP = 3,3’,5,5’-tetrachloro-2-iodo-4,4’-bipyridyl) are chiral compounds that showed interesting inhibition activity against transthyretin fibrillation in vitro. We became interested in their enantioseparation since we noticed that the M-stereoisomer is more effective than the P-enantiomer. Based thereon, we recently reported the enantioseparation of 2’-substituted TCIBP derivatives with amylose-based chiral columns. Following this study, herein we describe the comparative enantioseparation of both 2’-(4-pyridyl)- and 2’-(4-hydroxyphenyl)-TCIBPs on four cellulose phenylcarbamate-based chiral columns aiming to explore the effect of the polymer backbone, as well as the nature and position of substituents on the side groups on the enantioseparability of these compounds. In the frame of this project, the impact of subtle variations of analyte and polysaccharide structures, and mobile phase (MP) polarity on retention and selectivity was evaluated. The effect of temperature on retention and selectivity was also considered, and overall thermodynamic parameters associated with the analyte adsorption onto the CSP surface were derived from van ’t Hoff plots. Interesting cases of enantiomer elution order (EEO) reversal were observed. In particular, the EEO was shown to be dependent on polysaccharide backbone, the elution sequence of the two analytes being P-M and M-P on cellulose and amylose tris(3,5-dimethylphenylcarbamate), respectively. In this regard, a theoretical investigation based on molecular dynamics (MD) simulations was performed by using amylose and cellulose tris(3,5-dimethylphenylcarbamate) nonamers as virtual models of the polysaccharide-based selectors. This exploration at the molecular level shed light on the origin of the enantiodiscrimination processes.

The authors have declared no conflict of interest.

Data availability statement

The data that support the findings of this study are available in the supplementary material of this article.