This study developed a new method to methyl-esterify pectin using a cation exchange resin. Homogalacturonan (HG)-type pectin (WGPA-3-HG) and rhamnogalacturonan (RG)-I-type pectin (AHP-RG) obtained from the roots of Panax ginseng and sunflower heads, respectively, were used as models. Compared to commonly used methyl-esterification methods that use either methyl iodide or acidified methanol, the developed method can methyl-esterify both HG- and RG-I-type pectins without degrading their structures via β-elimination or acid hydrolysis. In addition, by modifying reaction conditions, including the mass ratio of resin to pectin, reaction time, and temperature, the degree of esterification can be controlled. Moreover, the resin and methanol can be recycled to conserve resources, lower costs, and reduce environmental pollution. This new methodology will be highly useful for industrial esterification of pectin.
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http://dx.doi.org/10.1016/j.carbpol.2015.11.005 | DOI Listing |
Chem Asian J
January 2025
University of North Texas, Department of Chemistry, 1508 W Mulberry St, 76201, Denton, UNITED STATES OF AMERICA.
Rhenium represents an irreplaceable metal resource, which finds extensive applications in diverse fields, particularly in the aerospace and petrochemical industry. However, its remarkably low natural abundance and the lack of independent ore deposits pose significant challenges to its extraction and recovery processes. In this study, we present the highly efficient adsorption of perrhenate by a cationic polymeric nanotrap material, namely CPN-3VIm.
View Article and Find Full Text PDFRSC Adv
January 2025
Electronic Material Research Center, Northwest Institute for Nonferrous Metal Research Xi'an 710016 China.
Potassium is a harmful impurity in the rhenium sinter, which adversely affects its mechanical properties by significantly reducing the density of sintered rhenium. Cationic resin is a promising material for potassium removal. In this study, the strong acid cationic exchange resin C160H was pretreated with an HNO solution to enhance its performance in potassium removal.
View Article and Find Full Text PDFSmall
January 2025
Department of Chemical Engineering, The Pennsylvania State University, University Park, PA, 16802, USA.
Vancomycin (VAN) and daptomycin (DAP) are among the last-resort antibiotics for treating multidrug-resistant Gram-positive bacterial infections. They are administered intravenously (IV); however, ≈5 - 10% of the total IV dose is released in the gastrointestinal (GI) tract via biliary excretion, driving resistance emergence in commensal Enterococcus faecium (E. faecium) populations.
View Article and Find Full Text PDFA method for analyzing tetrodotoxin (TTX) in miso soup samples was proposed. The samples were purified using strong cation exchange solid-phase extraction and analyzed by liquid chromatography-tandem mass spectrometry. The recovery of TTX was considerably influenced by the salt concentration in the loading solution during purification.
View Article and Find Full Text PDFSci Total Environ
January 2025
Key Laboratory of Coastal Environment and Resources of Zhejiang Province, School of Engineering, Westlake University, Hangzhou 310024, China. Electronic address:
Saltmarshes serve as repositories for various metal species, primarily due to vegetation removal and mineralization processes. However, the significance of potassium (K), one of the three major nutrients (nitrogen, phosphorus, and K) essential for plant growth, has often been overlooked, particularly in the context of saltmarshes where the mechanisms of K transport via porewater exchange remain poorly understood. To address this knowledge gap, we conducted field observations and laboratory analysis, and developed a Rn mass balance model to quantify K fluxes via porewater exchange under physical, biological, and anthropogenic drivers.
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