The coupling of hydrogen bonds is central to structures and functions of biological systems. Hydrogen bond coupling in sodium dihydrogen triacetate (SDHTA) is investigated as a model for the hydrogen bonded systems of the type O-H…O. The two-dimensional potential energy surface is derived from the full-dimensional one by selecting the relevant vibrational modes of the hydrogen bonds. The potential energy surfaces in terms of normal modes describing the anharmonic motion in the vicinity of the equilibrium geometry of SDHTA are calculated for the different species, namely, HH, HD, DH, and DD isotopomers. The ground state wave functions and their relation to the hydrogen bond structural parameters are discussed. It has been found that the hydrogen bonds in SDHTA are uncoupled, that is elongation of the deuterated hydrogen bond does not affect the non-deuterated one.
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http://dx.doi.org/10.1007/s00894-014-2363-9 | DOI Listing |
Acta Crystallogr C Struct Chem
January 2025
College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, People's Republic of China.
A new twofold interpenetrated 3D metal-organic framework (MOF), namely, poly[[μ-aqua-diaqua{μ-2,2'-[terephthaloylbis(azanediyl)]diacetato}barium(II)] dihydrate], {[Ba(CHNO)(HO)]·2HO}, (I), has been assembled through a combination of the reaction of 2,2'-[terephthaloylbis(azanediyl)]diacetic acid (TPBA, HL) with barium hydroxide and crystallization at low temperature. In the crystal structure of (I), the nine-coordinated Ba ions are bridged by two μ-aqua ligands and two carboxylate μ-O atoms to form a 1D loop-like Ba-O chain, which, together with the other two coordinated water molecules and μ-carboxylate groups, produces a rod-like secondary building unit (SBU). The resultant 1D polynuclear SBUs are further extended into a 3D MOF via the terephthalamide moiety of the ligand as a spacer.
View Article and Find Full Text PDFJ Comput Chem
January 2025
Department of Chemistry, Dr. Harisingh Gour Vishwavidyalaya, (A Central University), Sagar, India.
We report a direct application of the molecular tailoring approach-based (MTA-based) method to calculate the individual hydrogen bond (HB) energy in molecular crystal. For this purpose, molecular crystals of nitromalonamide (NMA) and salicylic acid (SA) were taken as test cases. Notably, doing a correlated computation using a large molecular crystal structure is difficult.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
School of Biological and Chemical Engineering, NingboTech University, Ningbo 315100, China. Electronic address:
Theaflavins, oxidation product of tea polyphenols, have demonstrated significant inhibitory effects on α-glucosidase, which is beneficial in alleviating hyperglycemia. This study found that the inhibition of four monomers of theaflavins on α-glucosidase was related to the presence of the galloyl moiety (GM), with IC values ranging from TFDG (0.26 mg/mL) < TF3'G (0.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
College of Food Science and Technology, Guangdong Ocean University, Zhanjiang 524088, China; Shenzhen Institute of Guangdong Ocean University, Shenzhen 518108, China; National Research and Development Branch Center for Shellfish Processing (Zhanjiang), Zhanjiang 524088, China; Guangdong Provincial Key Laboratory of Aquatic Products Processing and Safety, Guangdong Provincial Engineering Technology Research Center of Seafood, Zhanjiang 524088, China. Electronic address:
This study aimed to investigate the structural characteristics of Stichopus horrens collagen (SHC), Holothuria scabra collagen (HSC), and Holothuria leucospilota collagen (HLC) and to assess the effect of transglutaminase (TGase) on their film-forming properties. The results indicated that the collagens from three species of sea cucumbers were type I collagen with a complete triple helical structure. The thermal denaturation temperature of HLC (34.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Guangdong Key Laboratory of Intelligent Food Manufacturing, Foshan University, Foshan, Guangdong 528225, China; Department of Food Science, Foshan University, Foshan, Guangdong 528000, China. Electronic address:
The toughening coix seed oil (CSO) high internal phase Pickering emulsion (CSO-HIPES) and gel (CSO-HIPESG) comprised of carrageenan (CR)/super-deamidated-gluten (SDG) micro-particles (CR/SDG) were investigated via acid-heat induction. Results showed polysaccharide natural deep eutectic solvent (P-NADES) by citric acid-glucose-carrageenan ((CGCR), molar ratio at 1:1:0.035) was the crucial for the preparation of SDG (deamidation degree, 99.
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