A rapid and simple solvent system screening method was developed for pH-zone-refining counter-current chromatography (CCC) separation, which was much easier to find a suitable solvent system than the traditional method. Using this method, an optimal solvent system composed of hexane-ethyl acetate-methanol-water (3:7:1:9, v/v) was selected for pH-zone-refining CCC separation of alkaloids from the stems of Gelsemium elegans, where 10mM triethylamine (TEA) was added to the upper organic stationary phase as a retainer and 10mM hydrochloric acid (HCl) to the aqueous mobile phase as an eluter. As a result, six oxindole alkaloids, 420mg 19-xo-gelsenicine, 456mg gelsemine, 723mg koumine, 379mg 11-methoxygelsemamide, 342mg gelsenicine and 318mg humantenine were successfully purified in one step from 4.5g crude extract with the purity of over 95%, respectively. The structures of the oxindole alkaloids were identified by ESI-MS, (1)H NMR and (13)C NMR.
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http://dx.doi.org/10.1016/j.chroma.2013.07.069 | DOI Listing |
Int J Biol Macromol
January 2025
Zhejiang Provincial Engineering Research Center for Green and Low-carbon Dyeing & Finishing, Zhejiang Sci-Tech University, Hangzhou 310018, China; Zhejiang Provincial Innovation Center of Advanced Textile Technology, Shaoxing 312000, China. Electronic address:
Comparing to the solvent-based and waterborne polyurethanes (PU), the solvent-free reactive PU (RPU) is prepared via in-situ polymerization and film-formation of isocyanate-capped prepolymers and macromolecular polyols in solvent-free system. Thus, the carbon emissions and environmental pollutions are significantly reduced. However, the rapid polymerization also challenges the well control of structure and properties, especially the ordered microstructures.
View Article and Find Full Text PDFBioresour Technol
January 2025
University of Zagreb Faculty of Chemical Engineering and Technology, Marulićev trg 19, HR-10000 Zagreb, Croatia. Electronic address:
Efforts to reduce the impact of chemical processes on the environment are leading to a shift to enzymatic alternatives, with laccases standing out for their versatile substrate oxidation capabilities. This study addresses the improvement of biocatalytic reactions by deep eutectic solvents (DES), in particular DES-based aqueous two-phase systems (ATPS) for the extraction of biomolecules. Continuous laccase extraction from crude samples was achieved using a DES-based ATPS, which was first optimized in a batch extractor and later intensified in a microextractor.
View Article and Find Full Text PDFPharmaceutics
January 2025
Department of Pharmacy, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano, Italy.
Background/objectives: This study investigates for the first time the use of the prilling technique in combination with solvent evaporation to produce nano- and submicrometric PLGA particles to deliver properly an active pharmaceutical ingredient. Curcumin (CCM), a hydrophobic compound classified under BCS (Biopharmaceutics Classification System) class IV, was selected as the model drug.
Methods: Key process parameters, including polymer concentration, solvent type, nozzle size, and surfactant levels, were optimized to obtain stable particles with a narrow size distribution determined by DLS analysis.
Pharmaceutics
January 2025
Department of Chemical and Pharmaceutical Sciences, University of Trieste, Piazzale Europa 1, 34127 Trieste, Italy.
This study investigates the preparation of coamorphous systems composed entirely of active pharmaceutical ingredients (APIs), namely praziquantel, niclosamide, and mebendazole. The objective was to formulate and characterize binary and ternary coamorphous systems to evaluate their structural, thermal, and stability properties. Ten different mixtures (binary and ternary) were designed through a mixture design approach and prepared using a sustainable, one-step neat grinding process in a lab-scale vibrational mill.
View Article and Find Full Text PDFPharmaceutics
January 2025
Department of Pharmaceutical Sciences, Università degli Studi di Milano, via G: Colombo, 71, 20133 Milano, Italy.
Background/objectives: The objective of this paper is to design a novel film-forming system (FFS) based on Eudragit E PO (EuE) polymeric solutions, differing in volatile solvents (i.e., isopropanol and ethanol) and plasticizers (i.
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