- Preparation of a novel bridged bis(β-cyclodextrin) chiral stationary phase by thiol-ene click chemistry for enhanced enantioseparation in HPLC
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A bridged bis(β-cyclodextrin) ligand was firstly synthesized via a thiol-ene click chemistry reaction between allyl-ureido-β-cyclodextrin and 4-4′-thiobisthiophenol, which was then bonded onto a 5 μm spherical silica gel to obtain a novel bridged bis(β-cyclodextrin) chiral stationary phase (HTCDP). The structures of HTCDP and the bridged bis(β-cyclodextrin) ligand were characterized by the 1H nuclear magnetic resonance (1H NMR), solid state 13C nuclear magnetic resonance (13C NMR) spectra spectrum, scanning electron microscope, elemental analysis, mass spectrometry, infrared spectrometry and thermogravimetric analysis. The performance of HTCDP in enantioseparation was systematically examined by separating 21 chiral compounds, including 8 flavanones, 8 triazole pesticides and 5 other common chiral drugs (benzoin, praziquantel, 1-1′-bi-2-naphthol, Tr?ger's base and bicalutamide) in the reversed-phase chromatographic mode. By optimizing the chromatographic conditions such as formic acid content, mobile phase composition, pH values and column temperature, 19 analytes were completely separated with high resolution (1.50-4.48), in which the enantiomeric resolution of silymarin, 4-hydroxyflavanone, 2-hydroxyflavanone and flavanone were up to 4.34, 4.48, 3.89 and 3.06 within 35 min, respectively. Compared to the native β-CD chiral stationary phase (CDCSP), HTCDP had superior enantiomer separation and chiral recognition abilities. For example, HTCDP completely separated 5 other common chiral drugs, 2 flavanones and 3 triazole pesticides that CDCSP failed to separate. Unlike CDCSP, which has a small cavity (0.65 nm), the two cavities in HTCDP joined by the aryl connector could synergistically accommodate relatively bulky chiral analytes. Thus, HTCDP may have a broader prospect in enantiomeric separation, analysis and detection. This journal is
- Gong, Bolin,Guo, Siyu,Zhang, Ning
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p. 35754 - 35764
(2021/12/02)
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- HPLC method for separating enantiomers of imidazole derivatives - Antifungal compounds
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The aim of this study was to test separation possibility of enantiomers of nine active substances belonging to imidazole derivatives: bifonazole, butoconazole, econazole, enilconazole, fenticonazole, isoconazole, miconazole, sertaconazole and tioconazole. The study was performed using HPLC method and the CHIRALCEL OJ column (10 μm; 250 × 4.6 mm), the mobile phase flow rate of 0.8 mL/min and detection at 220 nm. Mobile phases containing hexane and the following modifiers: alcohols (2-propanol, ethanol, methanol) and diethylamine were tested. At first isocratic elution was used but some enantiomers eluted after a long retention time and their peaks were asymmetrical and too wide. Therefore, a gradient elution was developed allowing to obtain satisfactory retention times and other parameters of enentioseparation of the compounds.
- Podolska, Marzena,Bia?ecka, Wanda,Kulik, Anna,Kwiatkowska-Puchniarz, Barbara,Mazurek, Aleksander
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p. 777 - 784
(2017/06/05)
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- Chiral imidazole fungicidal compositions and methods for their use
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Chiral fungicides and compositions containing the same are provided. Also provided are methods for using the compositions of the present invention for inhibiting the growth of fungi, including phytotoxic fungi. The use of a single isomer in treating particular plant species and against particular fungi allows for selective inhibition of fungal growth with reduced fungicidal phytotoxic effects.
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