The 1:1 complex between quinuclidine and trifluoromethane has been investigated using pulsed jet Fourier transform microwave spectroscopy. The two constituting molecules are held together through a weak C-H···N hydrogen bond, with a H···N length of 2.070(1) Å. The C3 symmetric axes of the two moieties are collinear, making the overall molecular system a symmetric top. The HCF3 subunit is freely rotating with respect to the amine moiety. Transitions for the ground (m = 0) and for the first excited (|m| = 1) torsional states, with K up to 2, have been measured, all of them showing the (14)N nuclear quadrupole hyperfine structure. The dissociation energy of the complex has been estimated to be 10.2 kJ mol(-1).
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http://dx.doi.org/10.1021/jp411893p | DOI Listing |
Heliyon
January 2025
Institute of Agro-products Processing, Anhui Academy of Agricultural Sciences, Hefei, Anhui, 230041, China.
This study investigates the enhancement of gelatin (GEL) films using hydroxypropyl methylcellulose (HPMC) and carboxymethyl cellulose (CMC) for edible film packaging applications. Although GEL is biocompatible and cost-effective, its limited mechanical strength presents significant challenges for practical applications. The findings indicate that CMC effectively increases tensile strength (TS), while HPMC improves elongation at break (EAB) and hydrophilicity.
View Article and Find Full Text PDFPNAS Nexus
January 2025
Department of Pharmacology and Pharmaceutical Sciences, University of Southern California Mann School of Pharmacy and Pharmaceutical Sciences, 1985 Zonal Ave, Los Angeles, CA 90089-9121, USA.
Natural products are ligands and in vitro inhibitors of Alzheimer's disease (AD) tau. Dihydromyricetin (DHM) bears chemical similarity to known natural product tau inhibitors. Despite having signature polyphenolic character, DHM is ostensibly hydrophobic owing to intermolecular hydrogen bonds that shield hydrophilic phenols.
View Article and Find Full Text PDFBioact Mater
April 2025
Department of Mechanics and Engineering Science, College of Engineering, Peking University, Beijing, 100871, China.
Gelatin-based biomaterials have emerged as promising candidates for bioadhesives due to their biodegradability and biocompatibility. However, they often face limitations due to the uncontrollable phase transition of gelatin, which is dominated by hydrogen bonds between peptide chains. Here, we developed controllable phase transition gelatin-based (CPTG) bioadhesives by regulating the dynamic balance of hydrogen bonds between the peptide chains using 2-hydroxyethylurea (HU) and punicalagin (PA).
View Article and Find Full Text PDFFood Res Int
February 2025
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; Bio-resources Key Laboratory of Shaanxi Province, School of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong 723001, China; Quanzhou Marine Biotechnology Industry Research Institute, Quanzhou 362700, China. Electronic address:
The purpose of this study was to investigate the mechanism of enhancing gelling properties of low-salt surimi by utilizing the complementary advantages of L-arginine (L-Arg) and microwave (MW) from the perspective of gels' network characteristics. At MW 3 min, the diameters of protein filaments were increased from 0.015 μm to 0.
View Article and Find Full Text PDFFood Res Int
February 2025
School of Agriculture, Food and Ecosystem Sciences, Faculty of Science, The University of Melbourne, Parkville, Vic 3010, Australia. Electronic address:
In this study, octenyl succinic acid sodium starch (OSAS) decorated with chitosan (CS) of different molecular weights (50-150 kDa) and concentrations (10-30 mg/mL) was used to stabilize an emulsion coencapsulating with vitamin A (V) and vitamin D (V). The effect of CS decoration on the thermal and UV stability of the emulsion, as well as the underlying mechanism, was elucidated. The incorporation of CS increased the retention rates of V and V by 11.
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