β-Cyclodextrin-copper (II) complex as chiral selector in capillary electrophoresis for the enantioseparation of β-blockers

Chiral resolution of cationic piperazine derivatives by capillary electrophoresis using sulfated β-cyclodextrin

This research focuses on the development and validation of a capillary electrophoresis (CE) method for the chiral separation of three H1-antihistamine drugs chlorcyclizine, norchlorcyclizine, and neobenodine using sulfated β-cyclodextrin (S-β-CD) as the chiral selector. The study explores various factors influencing the separation efficiency, including CD concentration, organic modifier content, voltage application, and buffer pH. Optimal conditions were identified as a 100 mM phosphate buffer (pH 6.0) with 34 mg mL-1 S-β-CD and 40% (v/v) methanol. The method demonstrated excellent linearity in calibration curves, with coefficients of determination exceeding 0.99 for each enantiomer. Precision studies revealed good intra- and inter-day precision for migration times and peak areas. The limits of detection and quantification for the analytes were within the ranges of 5.9-11.4 and 18-34.6 µmol L-1, respectively. Overall, the developed CE method offers a robust and precise approach for the chiral separation of H1-antihistamine drugs, holding promise for pharmaceutical applications.

Analysis of β-blockers and β2-agonists in environmental and biological samples by magnetic solid-phase extraction combined with high-performance liquid chromatography-tandem mass spectrometry

β-Blockers and β2-agonists are commonly prescribed for therapeutic treatments and are also administered to livestock, leading to their presence in both environmental and biological samples. Hence, the development of sensitive, rapid, and reliable analytical methods for the determination of β-blockers and β2-agonists in environmental and biological samples is important. In this study, MIL-101(Cr)-NH₂ &GO-coated SiO₂ /Fe₃ O₄ magnetic particles were prepared as sorbents for magnetic solid-phase extraction and then combined with high-performance liquid chromatography-tandem mass spectrometry for the analysis of 20 β-blockers and eight β2-agonists. The experimental parameters of magnetic solid-phase extraction were studied in detail, and the optimal conditions were established. Under optimal conditions, the limits of detection were in the range of 0.002-0.007 μg/L with enrichment factors of 20.2-24.9. The developed method was successfully applied for the determination of 20 β-blockers and eight β2-agonists in river water, human urine, and freeze-dried pork liver powder. Bisoprolol and salbutamol were detected at concentrations of 2.78 mg/L in human urine and 11.5 μg/kg in freeze-dried pork liver powder.

A renewable electrochemical sensor based on a self-assembled framework of chiral molecules for efficient identification of tryptophan isomers

Molecular self-assembly provides a reasonably effective strategy for the design and construction of chiral sensors. Here, Cu²⁺ was connected to β-cyclodextrin (β-CD) through coordination to synthesize Cu₂-β-CD, subsequently assembled with ammoniated chitosan-MWCNTs (NH₂-CS-MWCNTs) by the effect of coordination driver to form a chiral sensing interface Cu₂-β-CD/NH₂-CS-MWCNTs. Using the electrochemical method, the valid recognition of tryptophan (Trp) isomers was achieved on the self-assembly interface. Under the optimal experimental conditions, the developed sensor exhibited good linearity and satisfactorily renewable ability. Cu₂-β-CD/NH₂-CS-MWCNTs/GCE showed the capacity to predict the ratio of D-Trp and L-Trp in racemic mixtures and the possibility of qualitative and quantitative determination for Trp isomers. Finally, the electrochemical sensor was used to detect the Trp enantiomers in rat serum, further verifying the feasibility of the sensor in the determination of actual samples. Therefore, the electrochemical chiral sensor not only is used for the recognition of Trp enantiomers but shows great potential in practical applications.

Theoretical electronic circular dichroism investigations of chiral amino acids and development of separation and identification methods independent of standards

Through an appropriate computational protocol and environmental simulation, a satisfactory fit was observed for the theoretical electronic circular dichroism (ECD) spectra of 19 chiral amino acids (AAs), which correspondeds to the forms of the AAs in aqueous solution. Methods for enantioseparation of these chiral AAs by capillary electrophoresis (CE) and high-performance liquid chromatography (HPLC) were developed. Combining ECD with chromatographic separation methods, enantiomers were identified and quantified independent of a single enantiomer standard.

Sugar-Based Ionic Liquids: Multifaceted Challenges and Intriguing Potential

Carbohydrates represent a promising option in transitioning from oil-based chemical resources to renewable ones, with the goal of developing chemistries for a sustainable future. Cellulose, hemicellulose, and largely available monosaccharides already provide useful chemical building blocks, so-called platform chemicals, such as levulinic acid and hydroxymethyl furfural, as well as solvents like cyrene or gamma-valerolactone. Therefore, there is great anticipation for novel applications involving materials and chemicals derived from sugars. In the field of ionic liquids (ILs), sugar-based ILs have been overlooked for a long time, mainly on account of their multistep demanding preparation. However, exploring new strategies for accessing sugar-based ILs, their study, and their exploitation, are attracting increasing interest. This is due to the growing concerns about the negative (eco)toxicity profile of most ILs in conjunction with their non-sustainable nature. In the present review, a literature survey concerning the development of sugar-based ILs since 2011 is presented. Their preparation strategies and thermal behavior analyses, sorted by sugar type, make up the first two sections with the intention to provide the reader with a useful guide. A final overview of the potential applications of sugar-based ILs and their future perspectives complement the present analysis.

Synthesis, application and molecular modeling study of ionic liquid functionalized lactobionic acid, 3-methyl-1-(3-sulfopropyl)-1H-imidazol-3-ium lactobionate, as a chiral selector in capillary electrophoresis

Ionic liquid MSI-LA was used as the sole chiral selector, both cation and anion contribute in forming interactions with enantiomers.

Enantioseparation of amino alcohol drugs by nonaqueous capillary electrophoresis with a maltobionic acid-based ionic liquid as the chiral selector

This study deals with the nonaqueous capillary electrophoretic enantioseparation of twenty-two amino alcohol drugs with a maltobionic acid (MA)-based ionic liquid (tetramethylammonium maltobionic acid, TMA-MA) as the novel chiral selector.