PhD Scientific Days 2025

Pharmaceutical Sciences and Health Technologies I.

Advances in Cyclodextrin-Assisted Capillary Electrophoresis for the Enantiomeric Separation of Structurally Diverse Chiral Compounds

Name of the presenter

Várnagy Erzsébet

Institute/workplace of the presenter

Department of Pharmacognosy, Semmelweis University

Authors

Erzsébet Várnagy¹, Gergő Tóth², Sándor Hosztafi², Milo Malanga³, Ida Fejős¹, Szabolcs Béni⁴

1: Department of Pharmacognosy, Semmelweis University, Budapest, Hungary
2: Department of Pharmaceutical Chemistry, Semmelweis University, Budapest, Hungary
3: CarboHyde Ltd, Budapest, Hungary
4: Department of Analytical Chemistry, Institute of Chemistry, Eötvös Loránd University, Budapest, Hungary

Text of the abstract

Introduction
Efficient enantiomeric separation remains a critical goal in pharmaceutical and natural product analysis, given the frequent differences in enantiomers’ pharmacodynamic and pharmacokinetic properties. Capillary electrophoresis (CE), particularly with cyclodextrin (CD) selectors, offers a rapid, environmentally friendly, and high-resolution approach to chiral analysis.

Aims
This study aimed to achieve baseline enantioseparation for two structurally distinct compound classes - a group of tetrahydrobenzylisoquinoline and tetrahydroprotoberberine alkaloids, and the kinase inhibitor idelalisib, using cyclodextrin-assisted CE. We further aimed to characterize host-guest complexation through NMR spectroscopy.

Methods
Over 20 native and derivatized CDs were screened for chiral recognition using CE. Chiral HPLC with polysaccharide-based columns was employed for semi-preparative enantiomer isolation of alkaloids, enabling precise determination of enantiomer migration order (EMO). Host-guest interactions were investigated via 1D and 2D NMR experiments.

Results
Multiple CDs provided significant chiral resolution for the tested alkaloids, with the best separation (Rs = 9.3) achieved for xylopinine using subetadex. Idelalisib enantiomers were baseline-separated using hydroxypropyl-β-CD, with favorable EMO and excellent reproducibility. Chiral HPLC further supported EMO assignment. ROESY spectra confirmed inclusion complex formation via diagnostic cross-peaks between analyte and CD protons.

Conclusion
Our study demonstrates that cyclodextrin-assisted CE, supported by NMR characterization and semi-preparative HPLC, enables reliable and selective enantioseparation for structurally unrelated chiral analytes. This methodology offers a broadly applicable platform for both natural product research and pharmaceutical quality control.

Funding
Funded by NKFIH FK 146930, Bicyclos No. 101130235, and SE 250+ Excellence PhD Scholarship.