Fritless particle-loaded monoliths for chiral capillary electrochromatographic (CEC) separation were prepared. Silica particles containing a chiral selector are suspended in a monomer solution, which is drawn into the capillary followed by in situ polymerization. Thereby the silica-based particles containing the chiral selector are embedded in a nonchiral continuous bed. This kind of chiral stationary phase is inexpensive, easy, and reproducible to prepare and circumvents the preparation of frits. As a model, teicoplanin aglycone as chiral selector bonded to 3 microm silica particles was used. The applicability of this approach is demonstrated by means of the chiral separation of aliphatic and aromatic amino acids and dipeptides. As a further application, the chiral selector ristocetin A bonded to 3 microm silica particles was used for the enantiomeric separation of chiral alpha-hydroxy acids. Since alpha-hydroxy acids migrate toward the anode, a cationic charge-providing agent was copolymerized with the matrix. This served to reverse the direction of the electroosmatic flow (EOF).
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http://dx.doi.org/10.1002/elps.200406038 | DOI Listing |
ACS Omega
January 2025
School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, 99 Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand.
The integration of molecular docking and AM1 calculations has elucidated the complexation behavior of butylone enantiomers with methylated β-cyclodextrin derivatives. Our study reveals that butylone can adopt two distinct conformations within the β-cyclodextrin cavity, with one conformation being preferentially stabilized due to its favorable binding energy. This conformation preference is influenced by the methylation at the O2, O3, and O6 positions of β-cyclodextrin, which significantly affects complex stability and solvation properties.
View Article and Find Full Text PDFNanoscale Adv
December 2024
Department of Pharmaceutical Chemistry, College of Pharmacy, Taif University Taif 21944 Saudi Arabia.
Mesoporous materials have garnered significant interest because of their porous structure, large surface area and ease of surface functionalization to incorporate the functional groups of choice. Herein, chiral mesoporous silica nanoparticles (CMSNPs) were prepared using quaternary amino silane as the template, tetramethyl orthosilicate as the silica source and proline and cellulose as chiral selector. The developed CMSNPs were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), elemental analysis, Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction analysis, BET surface area analysis and BJH pore size/volume analysis.
View Article and Find Full Text PDFBiosens Bioelectron
January 2025
School of Pharmacy, School of Clinical Medicine, Shandong Second Medical University, Weifang, 261053, China. Electronic address:
Chiral isomers show different behaviours and properties in physiological activities. It is of great significance to find productive approach to realize the recognition of enantiomers, which is a key issue in biochemical and pharmaceutical fields. Nowadays, chiral identification can be successfully achieved according to the discrepancies of special signals correlated with different enantiomers of multiple electrode structures.
View Article and Find Full Text PDFElectrophoresis
January 2025
Institute for Infectious Diseases, University of Bern, Bern, Switzerland.
Computer simulation was utilized to characterize the electrophoretic processes occurring during the enantioselective capillary electrophoresis-mass spectrometry (CE-MS) analysis of ketamine, norketamine, and hydroxynorketamine in a system with partial filling of the capillary with 19 mM (equals 5%) of highly sulfated γ-cyclodextrin (HS-γ-CD) and analyte detection on the cathodic side. Provided that the sample is applied without or with a small amount of the chiral selector, analytes become quickly focused and separated in the thereby formed HS-γ-CD gradient at the cathodic end of the sample compartment. This gradient broadens with time, remains stationary, and gradually reduces its span from the lower side due to diffusion such that analytes with high affinity to the anionic selector become released onto the other side of the focusing gradient where anionic migration and defocusing occur concomitantly.
View Article and Find Full Text PDFAnal Chim Acta
February 2025
Institute of Physical and Analytical Chemistry, School of Exact and Natural Sciences, Tbilisi State University, 0179, Tbilisi, Georgia. Electronic address:
Background: Isotopologues resulting from the labelling of molecules with deuterium have attracted interest due to the isotope effect observed in chemistry and biosciences. Isotope effect may also play out in noncovalent interactions and mechanisms leading to intermolecular recognition. In chromatography, differences in retention time between isotopologues, as well as between isotopomers have been observed resulting in two different elution sequences (isotope effects): the normal isotope effect when heavier isotopologues retain longer than lighter analogues, and the inverse isotope effect featuring the opposite elution order.
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