Background: The effort for implementing more environmentally-conscious practices has also gained momentum in separation techniques. One possible approach is replacing conventional solvents with alternative solvents that are less hazardous to health/environment. Due to properties of chiral liquid crystals, their enantioselective chromatography is mostly conducted under normal mode or polar organic mode conditions with acetonitrile-rich mobile phase. It is apparent there is a room for employing less polluting solvents.
Results: Dimethyl carbonate, propylene carbonate and dimethoxymethane (methylal) were used as mobile phase components for direct enantioseparation of six chiral liquid crystals on chlorinated polysaccharide-based chiral stationary phase (CSP). The chromatographic behaviour of the selected solutes has been previously studied in acetonitrile-based mobile phases on the same CSP which enabled a comparison of the results obtained with conventional solvents and those obtained with the greener solvents. Each of the green solvents was used instead of acetonitrile in binary mobile phases with methanol or 2-propanol. Fast baseline enantioseparations (retention factor of the late eluting enantiomer k < 2) were achieved for five out of six analytes; for the last analyte baseline enantioseparation has been achieved at longer time. Aqueous mobile phases were also tested and enabled baseline separation of three solutes. Effect of flow-rate on the separation efficiency is briefly discussed as well as suitability of the three solvents for use as sample solvents.
Significance: The is the first use of propylene carbonate and methylal in enantioselective chromatography. The green solvents were found to be suitable alternatives to acetonitrile for chiral separation of liquid crystalline materials as all six analytes were separated to baseline using acetonitrile-free mobile phases. Practical aspects of working with the selected green solvents are briefly summarized.
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http://dx.doi.org/10.1016/j.aca.2025.343664 | DOI Listing |
Int J Cosmet Sci
March 2025
Institute of Analytical Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology in Bratislava, Bratislava, Slovakia.
Objective: This work deals with the development of an analytical method for the analysis of body milk, cream, and oil. The objective is to develop a reliable, sensitive, and reproducible method suitable to assess the content of dexpanthenol in personal care products and to confirm the declared enantiomeric form.
Methods: Optimization of conditions for the extraction of panthenol from personal care products was carried out for the detection and quantification of panthenol and its enantiomers by achiral and chiral high-performance liquid chromatography (HPLC) with spectrophotometric detection.
Org Biomol Chem
March 2025
Graduate School of Science and Technology, Niigata University, Nishi-ku, Niigata, 950-2181, Japan.
Hydrogenated isoprenoids are found in a range of biologically important natural products, such as isoprenoid quinones, chlorophyll, vitamin E, and dolichol. In this study, a new method was developed for determining the chirality of the tetrahydrogenated isoprenoid (THI) structures of two natural products, namely heptaprenylcycli-14,18-diene and (22,5,9,13,17)-6,10,14,18,22,26-hexamethylheptacosa-5,9,13,17-tetraen-2-one, for which the chiral carbon centres have never been elucidated. Our research group previously isolated the former sesquarterpene from , while the latter was isolated as a new polyprenyl acetone from in the current study.
View Article and Find Full Text PDFMolecules
February 2025
Integrative Health and Environmental Analysis Research Laboratory, Department of Analytical Chemistry, Institute of Chemistry, ELTE Eötvös Loránd University, Pázmány Péter sétány 1/A, H-1117 Budapest, Hungary.
The tetrahydroisoquinoline skeleton is a pharmacologically significant core structure containing chiral centers, making enantiomeric separation crucial due to the potentially distinct biological effects of each enantiomer. In this study, laudanosine (-methyl-tetrahydropapaverine) and its three derivatives (6'-bromo-laudanosine, norlaudanosine, and -propyl-norlaudanosine) were synthesized and used as model compounds to investigate chiral recognition mechanisms. Screening over twenty cyclodextrins (CyDs) as chiral selectors in capillary electrophoresis (CE), we found anionic CyDs to be the most effective, with sulfated-γ-CyD (S-γ-CyD) achieving a maximum of 10.
View Article and Find Full Text PDFMolecules
February 2025
Centre for the Control and Evaluation of Medicines, Chemical Medicines Unit, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy.
Midazolam is a benzodiazepine that is utilized for the induction of anesthesia and the facilitation of procedural sedation. Despite the absence of stereogenic centers, the non-planar seven-membered ring devoid of reflection symmetry elements confers planar stereogenicity to the molecule. Due to the rapid conformational inversion of the and enantiomers, which occurs via a simple ring flip, high-performance liquid chromatography (HPLC) enantiomeric separation is restricted to sub-room temperature conditions.
View Article and Find Full Text PDFChem Sci
March 2025
Ōmura Satoshi Memorial Institute, Graduate School of Infection Control Sciences, Kitasato University 5-9-1 Shirokane, Minato-ku Tokyo 108-8641 Japan
Macrocyclic peptides, including depsipeptides, are an emerging new modality in drug discovery research. Tetraselide, an antifungal cyclic peptide isolated from a marine-derived filamentous fungus, possesses a unique amphiphilic structural feature consisting of five consecutive β-hydroxy-amino acid residues and fatty acid moieties. Because the structure elucidation of the naturally occurring product left six stereocenters ambiguous, we implemented bioinformatic analyses, chemical degradation studies and chiral pool fragment synthesis to identify two of the undetermined stereocenters.
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