Role of the Carbohydrate Moieties in Chiral Recognition on Teicoplanin- based LC Stationary Phases

Author

Alain Berthod, Missouri University of Science and Technology
Xianghong Chen
John P. Kullman
Daniel W. Armstrong, Missouri University of Science and Technology
Francesco Gasparrini
Ilaria D'Acquarica
Claudio Villani
Angelo Carotti

Abstract

For this study, we used the macrocyclic antibiotic teicoplanin, a molecule consisting of an aglycone peptide 'basket' with three attached carbohydrate (sugar) moieties. The sugar units were removed and the aglycone was purified. Two chiral stationary phases (CSPs) were prepared in a similar way, one with the native teicoplanin molecule and the other with the aglycone. Twenty-six compounds were evaluated on the two CSPs with seven RPLC mobile phases and two polar organic mobile phases. The compounds were 13 amino acids or structurally related compounds (including DOPA, folinic acid, etc.) and 13 other compounds (such as carnitine, bromacil, etc.). The chromatographic results are given as the retention, selectivity, and resolution factors along with the peak efficiency and the enantioselective free energy difference corresponding to the separation of the two enantiomers. The polarities of the two CSPs are similar. It is clearly established that the aglycone is responsible for the enantioseparation of amino acids. The difference in enantioselective free energy between the aglycone CSP and the teicoplanin CSP was between 0.3 and 1 kcal/mol for amino acid enantioseparations. This produced resolution factors 2-5 times higher with the aglycone CSP. Four non amino acid compounds were separated only on the teicoplanin CSP. Six and five compounds were better separated on the teicoplanin and aglycone CSPs, respectively. Although the sugar units decrease the resolution of α-amino acid enantiomers, they can contribute significantly to the resolution of a number of non-amino acid enantiomeric pairs.

Recommended Citation

A. Berthod et al., "Role of the Carbohydrate Moieties in Chiral Recognition on Teicoplanin- based LC Stationary Phases," Analytical Chemistry, vol. 72, no. 8, pp. 1767 - 1780, American Chemical Society, Apr 2000.

The definitive version is available at https://doi.org/10.1021/ac991004t

Department(s)

Chemistry

Comments

National Institute of General Medical Sciences, Grant R01GM053825

International Standard Serial Number (ISSN)

0003-2700

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2024 American Chemical Society, All rights reserved.

Publication Date

15 Apr 2000

PubMed ID

10784140