Deuterium ((2) H) magic-angle spinning (MAS) nuclear magnetic resonance is applied to monitor the dynamics of the exchanging labile deuterons of polycrystalline L-histidine hydrochloride monohydrate-d7 and α-oxalic acid dihydrate-d6 . Direct experimental evidence of fast dynamics is obtained from T1Z and T1Q measurements. Further motional information is extracted from two-dimensional single-quantum (SQ) and double-quantum (DQ) MAS spectra. Differences between the SQ and DQ linewidths clearly indicate the presence of motions on intermediate timescales for the carboxylic moiety and the D2 O in α-oxalic acid dihydrate, and for the amine group and the D2 O in L-histidine hydrochloride monohydrate. Comparison of the relaxation rate constants of Zeeman and quadrupolar order with the relaxation rate constants of the DQ coherences suggests the co-existence of fast and slow motional processes.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/cphc.201402506 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Development studies on the orodispersible freeze-dried platforms for lurasidone hydrochloride - Understanding the effect of amino acid additive and lyophilization stage.
Int J Pharm
December 2024
Department of Pharmaceutical Technology, Medical University of Białystok, Mickiewicza 2c, 15-222 Bialystok, Poland. Electronic address:
In this study, lyophilizates with the second-class antipsychotic agent lurasidone hydrochloride were developed as orodispersible platforms to improve patients' adherence. The primary aim was to evaluate the effect of the amino acid additive (L-arginine, L-lysine, L-histidine) and the freeze-drying stage on the pharmaceutical performance of the designed formulations. The composition was initially optimized using an experimental design approach.
View Article and Find Full Text PDFHigh-resolution indirect detection of spin-3/2 quadrupolar nuclei in solids using multiple-quantum-filtered through-space D-HMQC experiments.
Solid State Nucl Magn Reson
December 2024
Univ. Lille, CNRS, Centrale Lille, Univ. Artois, UMR 8181 - UCCS- Unité de Catalyse et de Chimie Du Solide, F-59000, Lille, France. Electronic address:
Through-space heteronuclear correlation experiments under magic-angle spinning (MAS) conditions can provide unique insights into inter-atomic proximities. In particular, it has been shown that experiments based on two consecutive coherence transfers, H → I → H, like D-HMQC (dipolar-mediated heteronuclear multiple-quantum correlation), are usually more sensitive for the indirect detection via protons of spin-3/2 quadrupolar nuclei with low gyromagnetic ratio. Nevertheless, the resolution is often decreased by the second-order quadrupolar broadening along the indirect dimension.
View Article and Find Full Text PDFHarnessing Guanidinium and Imidazole Functional Groups: A Dual-Charged Polymer Strategy for Enhanced Gene Delivery.
ACS Macro Lett
August 2024
Institute of Organic Chemistry and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743 Jena, Germany.
Histidine and arginine are two amino acids that exhibit beneficial properties for gene delivery. In particular, the imidazole group of histidine facilitates endosomal release, while the guanidinium group of arginine promotes cellular entry. Consequently, a dual-charged copolymer library based on these amino acids was synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization.
View Article and Find Full Text PDF[Mechanism of Jiming Powder in ameliorating heart failure with preserved ejection fraction based on metabolomics].
Zhongguo Zhong Yao Za Zhi
September 2023
School of Traditional Chinese Medicine, Beijing University of Chinese Medicine Beijing 100029, China.
In this study, untargeted metabolomics was conducted using the liquid chromatography-tandem mass spectrometry(LC-MS/MS) technique to analyze the potential biomarkers in the plasma of mice with heart failure with preserved ejection fraction(HFpEF) induced by a high-fat diet(HFD) and nitric oxide synthase inhibitor(Nω-nitro-L-arginine methyl ester hydrochloride, L-NAME) and explore the pharmacological effects and mechanism of Jiming Powder in improving HFpEF. Male C57BL/6N mice aged eight weeks were randomly assigned to a control group, a model group, an empagliflozin(10 mg·kg~(-1)·d~(-1)) group, and high-and low-dose Jiming Powder(14.3 and 7.
View Article and Find Full Text PDFEffects of Nutrients on the Growth of and Free Exopolysaccharide Biosynthesis by Streptococcus thermophilus 937 in a Chemically Defined Medium.
Curr Microbiol
August 2023
Key Lab of Dairy Biotechnology and Safety Control, Yangzhou University, Yangzhou, 225127, Jiangsu Province, China.
Article Synopsis
- The study investigates the nutritional needs for the growth and production of free exopolysaccharide (f-EPS) by the bacterium Streptococcus thermophilus, which has health benefits and is used as a texture modifier.
- Key nutrients like cysteine, glutamine, and specific B vitamins were identified as crucial for the stable growth of S. thermophilus 937, while lactose and certain amino acids significantly enhanced f-EPS production.
- Optimal conditions for maximum f-EPS yield were found with 20 g·L of lactose and a combination of three amino acids at 15 mM, indicating a synergistic effect between these nutrients on f-EPS production.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!