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19 Results Found

  • Article
  • Open Access
1 Citations
3,156 Views
16 Pages

Development of Novel Immobilized Copper–Ligand Complex for Click Chemistry of Biomolecules

  • Rene Kandler,
  • Yomal Benaragama,
  • Manoranjan Bera,
  • Caroline Wang,
  • Rasheda Aktar Samiha,
  • W. M. C. Sameera,
  • Samir Das and
  • Arundhati Nag

Copper-catalyzed azide–alkyne cycloaddition click (CuAAC) reaction is widely used to synthesize drug candidates and other biomolecule classes. Homogeneous catalysts, which consist of copper coordinated to a ligand framework, have been optimized...

  • Article
  • Open Access
7 Citations
3,535 Views
12 Pages

Electron Spin Relaxation of Photoexcited Porphyrin in Water—Glycerol Glass

  • Natalya Sannikova,
  • Ivan Timofeev,
  • Elena Bagryanskaya,
  • Michael Bowman,
  • Matvey Fedin and
  • Olesya Krumkacheva

Recently, the photoexcited triplet state of porphyrin was proposed as a promising spin-label for pulsed dipolar electron paramagnetic resonance (EPR). Herein, we report the factors that determine the electron spin echo dephasing of the photoexcited p...

  • Article
  • Open Access
34 Citations
5,800 Views
15 Pages

Deuteration-Induced Volume Phase Transition Temperature Shift of PNIPMAM Microgels

  • Marian Cors,
  • Lars Wiehemeier,
  • Julian Oberdisse and
  • Thomas Hellweg

3 April 2019

The effect of deuteration on the volume phase transition (VPT) temperature of poly (N-isopropylmethacrylamide) (pNIPMAM) microgels in aqueous suspension is determined via IR spectroscopy and size measurements by photon correlation spectroscopy (PCS)....

  • Feature Paper
  • Article
  • Open Access
2 Citations
3,443 Views
14 Pages

Straightforward and Efficient Deuteration of Terminal Alkynes with Copper Catalysis

  • Xènia Tarrach,
  • Jingzhou Yang,
  • Mohammad Soleiman-Beigi and
  • Silvia Díez-González

23 March 2023

The mild and effective preparation of deuterated organic molecules is an active area of research due to their important applications. Herein, we report an air-stable and easy to access copper(I) complex as catalyst for the deuteration of mono-substit...

  • Article
  • Open Access
17 Citations
5,337 Views
10 Pages

29 January 2020

We used a combination of density functional theory (DFT) calculations and the implicit quantization of the acidic N–H and O–H bonds to assess the effect of deuteration on the binding of agonists (2-methylhistamine and 4-methylhistamine) a...

  • Article
  • Open Access
1 Citations
2,353 Views
20 Pages

Optimization of Extraction Methods for NMR and LC-MS Metabolite Fingerprint Profiling of Botanical Ingredients in Food and Natural Health Products (NHPs)

  • Varathan Vinayagam,
  • Arunachalam Thirugnanasambandam,
  • Subramanyam Ragupathy,
  • Ragupathy Sneha and
  • Steven G. Newmaster

14 August 2025

Metabolite fingerprint profiling is a robust tool for verifying suppliers of authentic botanical ingredients. While comparative studies exist, few apply identical conditions across multiple species; this study utilized a cross-species comparison to i...

  • Article
  • Open Access
5 Citations
3,806 Views
16 Pages

H/D Exchange Processes in Flavonoids: Kinetics and Mechanistic Investigations

  • Federico Bonaldo,
  • Fulvio Mattivi,
  • Daniele Catorci,
  • Panagiotis Arapitsas and
  • Graziano Guella

10 June 2021

Several classes of flavonoids, such as anthocyanins, flavonols, flavanols, and flavones, undergo a slow H/D exchange on aromatic ring A, leading to full deuteration at positions C(6) and C(8). Within the flavanol class, H-C(6) and H-C(8) of catechin...

  • Article
  • Open Access
4,547 Views
10 Pages

Benchtop 19F Nuclear Magnetic Resonance (NMR) Spectroscopy-Optimized Knorr Pyrazole Synthesis of Celecoxib and Mavacoxib, 3-(Trifluoromethyl) Pyrazolyl Benzenesulfonamides, Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

  • Andrew Chyu,
  • Selina Xi,
  • Joshua Kim,
  • Galen Liu,
  • Indalina Chan,
  • Seoyeon Hong,
  • Allen Ke,
  • Thomas Lavery,
  • Anushree Marimuthu and
  • Edward Njoo
  • + 1 author

11 November 2024

Fluorinated organic compounds have demonstrated remarkable utility in medicinal chemistry due to their enhanced metabolic stability and potent therapeutic efficacy. Several examples exist of fluorinated non-steroidal anti-inflammatory drugs (NSAIDs),...

  • Article
  • Open Access
19 Citations
4,850 Views
17 Pages

H/D Isotope Effects on 1H-NMR Chemical Shifts in Cyclic Heterodimers and Heterotrimers of Phosphinic and Phosphoric Acids

  • Valeriia V. Mulloyarova,
  • Daria O. Ustimchuk,
  • Aleksander Filarowski and
  • Peter M. Tolstoy

20 April 2020

Hydrogen-bonded heterocomplexes formed by POOH-containing acids (diphenylphosphoric 1, dimethylphosphoric 2, diphenylphosphinic 3, and dimethylphosphinic 4) are studied by the low-temperature (100 K) 1H-NMR and 31P-NMR using liquefied gases CDF3/CDF2...

  • Article
  • Open Access
1 Citations
1,790 Views
17 Pages

Extraction Methods for Brain Biopsy NMR Metabolomics: Balancing Metabolite Stability and Protein Precipitation

  • Wenzheng Xiong,
  • Florian Zirpel,
  • M. Zameel Cader,
  • Daniel C. Anthony and
  • Fay Probert

10 November 2024

Background/Objectives: Metabolic profiling of tissue samples via liquid-state nuclear magnetic resonance (NMR) requires the extraction of polar metabolites in a suitable deuterated solvent. Such methods often prioritise metabolite recovery over prote...

  • Article
  • Open Access
11 Citations
4,707 Views
22 Pages

Conformations of Steroid Hormones: Infrared and Vibrational Circular Dichroism Spectroscopy

  • Yanqing Yang,
  • Anna Krin,
  • Xiaoli Cai,
  • Mohammad Reza Poopari,
  • Yuefei Zhang,
  • James R. Cheeseman and
  • Yunjie Xu

12 January 2023

Steroid hormone molecules may exhibit very different functionalities based on the associated functional groups and their 3D arrangements in space, i.e., absolute configurations and conformations. Infrared (IR) and vibrational circular dichroism (VCD)...

  • Article
  • Open Access
24 Citations
4,023 Views
7 Pages

Screening Effective Antifungal Substances from the Bark and Leaves of Zanthoxylum avicennae by the Bioactivity-Guided Isolation Method

  • Yongtong Xiong,
  • Guan Huang,
  • Zongli Yao,
  • China Zhao,
  • Xiang Zhu,
  • Qinglai Wu,
  • Xudong Zhou and
  • Junkai Li

20 November 2019

To find good antifungal substances by the bioactivity-guided isolation method, we tracked down the effective antifungal substances in the bark and leaves of Zanthoxylum avicennae, and isolated three antifungal compounds 1, 2, and 3. The structures we...

  • Communication
  • Open Access
17 Citations
10,953 Views
6 Pages

Conformational Screening of Arbidol Solvates: Investigation via 2D NOESY

  • Varvara A. Eventova,
  • Konstantin V. Belov,
  • Sergey V. Efimov and
  • Ilya A. Khodov

Understanding of the nucleation process’s fundamental principles in saturated solutions is an urgent task. To do this task, it is necessary to control the formation of polymorphic forms of biologically active compounds. In certain cases, a comp...

  • Article
  • Open Access
15 Citations
4,044 Views
25 Pages

Intermolecular Interactions and Spectroscopic Signatures of the Hydrogen-Bonded System—n-Octanol in Experimental and Theoretical Studies

  • Michał Pocheć,
  • Katarzyna M. Krupka,
  • Jarosław J. Panek,
  • Kazimierz Orzechowski and
  • Aneta Jezierska

11 February 2022

n-Octanol is the object of experimental and theoretical study of spectroscopic signatures and intermolecular interactions. The FTIR measurements were carried out at 293 K for n-octanol and its deuterated form. Special attention was paid to the vibrat...

  • Communication
  • Open Access
18 Citations
3,320 Views
13 Pages

Coated Blade Spray-Mass Spectrometry as a New Approach for the Rapid Characterization of Brain Tumors

  • Joanna Bogusiewicz,
  • Magdalena Gaca-Tabaszewska,
  • Dominik Olszówka,
  • Karol Jaroch,
  • Jacek Furtak,
  • Marek Harat,
  • Janusz Pawliszyn and
  • Barbara Bojko

30 March 2022

Brain tumors are neoplasms with one of the highest mortality rates. Therefore, the availability of methods that allow for the quick and effective diagnosis of brain tumors and selection of appropriate treatments is of critical importance for patient...

  • Feature Paper
  • Article
  • Open Access
7 Citations
3,231 Views
23 Pages

20 July 2021

Using dynamic liquid-state NMR spectroscopy a degenerate double proton tautomerism was detected in tetramethyl reductic acid (TMRA) dissolved in toluene-d8 and in CD2Cl2. Similar to vitamin C, TMRA belongs to the class of reductones of biologically i...

  • Article
  • Open Access
1,828 Views
17 Pages

Cuscohygrine and Hygrine as Biomarkers for Coca Leaf Chewing: Analytical Challenges in GC-MS Detection and Implications for the Differentiation of Cocaine Use in Forensic Toxicology

  • Nélida C. Rubio,
  • Iván Alvarez-Freire,
  • Pamela Cabarcos-Fernández,
  • María J. Tabernero-Duque,
  • Inés Sánchez-Sellero,
  • Antonio Moreda-Piñeiro,
  • Pilar Bermejo-Barrera and
  • Ana M. Bermejo-Barrera

Cuscohygrine (CUS) and hygrine (HYG) are pyrrolidine alkaloids proposed as biomarkers of coca leaf consumption, a culturally accepted practice in some Latin American countries. Differentiating legal coca use from illicit cocaine consumption holds for...

  • Article
  • Open Access
13 Citations
6,124 Views
20 Pages

7 December 2018

Aqueous solutions of Lu3+- perchlorate, triflate and chloride were measured by Raman spectroscopy. A weak, isotropic mode at 396 cm−1 (full width at half height (fwhh) at 50 cm−1) was observed in perchlorate and triflate solutions. This m...

  • Article
  • Open Access
4 Citations
2,583 Views
19 Pages

Quality Control in Targeted GC-MS for Amino Acid-OMICS

  • Dimitrios Tsikas and
  • Bibiana Beckmann

31 August 2023

Gas chromatography-mass spectrometry (GC-MS) is suitable for the analysis of non-polar analytes. Free amino acids (AA) are polar, zwitterionic, non-volatile and thermally labile analytes. Chemical derivatization of AA is indispensable for their measu...