Quinine-Based Zwitterionic Chiral Stationary Phase as a Complementary Tool for Peptide Analysis: Mobile Phase Effects on Enantio- and Stereoselectivity of Underivatized Oligopeptides.
Peptide stereoisomer analysis is of importance for quality control of therapeutic peptides, the analysis of stereochemical integrity of bioactive peptides in food, and the elucidation of the stereochemistry of peptides from a natural chiral pool which often contains one or more D-amino acid residues. In this work, a series of model peptide stereoisomers (enantiomers and diastereomers) were analyzed on a zwitterionic ion-exchanger chiral stationary phase (Chiralpak ZWIX(+) 5 µm), in order to investigate the retention and separation performance for such compounds on this chiral stationary phase and elucidate its utility for this purpose. The goal of the study focused on 1) investigations of the effects of the sample matrix used to dissolve the peptide samples; 2) optimization of the mobile phase (enabling deriving information on factors of relevance for retention and separation); and 3) derivation of structure-selectivity relationships. It turned out that small di- and tripeptides can be well resolved under optimized conditions, typically with resolutions larger than 1.5. The optimized mobile phase often consisted of methanol-tetrahydrofuran-water (49:49:2; v/v/v) with 25 mM formic acid and 12.5 mM diethylamine. This work proposes some guidance on which mobile phases can be most efficiently used for peptide stereoisomer separations on Chiralpak ZWIX. Chirality 28:5-16, 2016. © 2015 Wiley Periodicals, Inc.
Institute of Pharmaceutical Sciences, University of Tübingen, Tübingen, Germany.|Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy.
Federica
F
Ianni
Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy.
Roccaldo
R
Sardella
Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy.
Andrea
A
Carotti
Department of Pharmaceutical Sciences, University of Perugia, Perugia, Italy.
Benedetto
B
Natalini
Department of Analytical Chemistry, University of Vienna, Vienna, Austria.
Wolfgang
W
Lindner
Institute of Pharmaceutical Sciences, University of Tübingen, Tübingen, Germany.
Michael
M
Lämmerhofer
D000596:Amino Acids / Q000737:chemistry*; D015394:Molecular Structure; D009842:Oligopeptides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011803:Quinine / Q000737:chemistry*; D013237:Stereoisomerism; D013696:Temperature; D013816:Thermodynamics
D000596:Amino Acids; D009842:Oligopeptides; D010455:Peptides; D011803:Quinine
Cinchona alkaloid; enantiomer separation; liquid chromatography; peptides; quinine carbamate; zwitterionic chiral stationary phase