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Yakugaku Zasshi : Journal of the... 2013Deuterium (D) labeled compounds are utilized in various scientific fields such as mechanistic elucidation of reactions, preparation of new functional materials, tracers... (Review)
Review
Deuterium (D) labeled compounds are utilized in various scientific fields such as mechanistic elucidation of reactions, preparation of new functional materials, tracers for microanalysis, deuterium labeled heavy drugs and so on. Although the H-D exchange reaction is a straightforward method to produce deuterated organic compounds, many precedent methods require expensive deuterium gas and/or harsh reaction conditions. A part of our leading research agendas is intended to the development of novel and functional heterogeneous platinum-group catalysts and the reclamation of unknown functionalities of existing heterogeneous platinum-group catalysts. During the course of the study, benzylic positions of substrates were site-selectively deuterated under mild and palladium-on-carbon (Pd/C)-catalyzed hydrogenation conditions in heavy water (D2O). Heat conditions promoted the H-D exchange reactivity and facilitated the H-D exchange reaction at not only the benzylic sites but also inactive C-H bonds and heterocyclic nuclei. It is noteworthy that platinum-on-carbon (Pt/C) indicated a quite high affinity toward aromatic nuclei, and the H-D exchange reaction was strongly enhanced by the use of Pt/C as a catalyst under milder conditions. The mixed use of Pd/C and Pt/C was found to be more efficient in the H-D exchange reaction compared to the independent use of Pd/C or Pt/C. Furthermore, simple alkanes could also be efficiently deuterated under rhodium-on-carbon (Rh/C)-catalyzed conditions. The use of ruthenium-on-carbon (Ru/C) enabled the regiospecific and efficient deuterium incorporation at α-positions of alcohols and results were applied as a regio- and stereoselective multi-deuteration method of sugar derivatives.
Topics: Carbohydrates; Carbon; Catalysis; Deuterium; Platinum
PubMed: 24189559
DOI: 10.1248/yakushi.13-00218 -
The New Phytologist Nov 2022Determining whether isotope fractionation occurs during root water uptake is a prerequisite for using stem or xylem water isotopes to trace water sources. However, it is...
Determining whether isotope fractionation occurs during root water uptake is a prerequisite for using stem or xylem water isotopes to trace water sources. However, it is unclear whether isotope fractionation occurs during root water uptake in gramineous crops. We conducted prevalidation experiments to estimate the isotope measurement bias associated with cryogenic vacuum distillation (CVD). Next, we assessed isotope fractionation during root water uptake in two common agronomic crops, wheat (Triticum aestivum L.) and maize (Zea mays L.), under flooding after postdrought stress conditions. Cryogenic vacuum distillation caused significant depletion of H but negligible effects on O for both soil and stem water. Surprisingly CVD caused depletion of H and enrichment of O in root water. Stem and root water δ O were more than soil water δ O, even considering the uncertainty of CVD. Soil water O was depleted compared with irrigation water O in the pots with plants but enriched relative to irrigation water O in the pots without plants. These results indicate that isotope fractionation occurred during wheat and maize root water uptake after full irrigation and led to a heavy isotope enrichment in stem water. Therefore, the xylem/stem water isotope approach widely used to trace water sources should be carefully evaluated.
Topics: Water; Oxygen Isotopes; Deuterium; Poaceae; Soil; Triticum; Crops, Agricultural; Zea mays; Fluid Therapy; Cardiovascular Diseases
PubMed: 35945699
DOI: 10.1111/nph.18423 -
Molecular Biotechnology May 2022The hydrogen/deuterium (H/D) exchange of main-chain amide hydrogens in the protein that denatured and refolded in deuterated solvent is considered to contain the traces...
The hydrogen/deuterium (H/D) exchange of main-chain amide hydrogens in the protein that denatured and refolded in deuterated solvent is considered to contain the traces of hydrogen bond cleavages or the exposure to solvent of the buried part of the protein during the denaturing and refolding (denaturing/refolding) processes. Here, we report the H/D exchange behaviors in hen egg-white lysozymes denatured under acidic conditions, basic conditions, and thermal conditions and then refolded in deuterated solvents, using crystallographic methods. The results indicate that the space containing the Trp28 side chain was hardly exposed to the solvent in acidic conditions, but exposed under basic or heated conditions. Moreover, the β-bridges between Tyr53 and Ile58 in strands β2 and β3, which are in a highly conserved region, show some tolerance to changes in pD. The results indicate that crystallographic method is one of the powerful tools to analyze the denaturing/refolding processes of proteins.
Topics: Animals; Chickens; Deuterium; Hydrogen; Muramidase; Protein Denaturation; Proteins; Solvents
PubMed: 35028904
DOI: 10.1007/s12033-022-00447-7 -
Nature Communications Jul 2023Separating deuterium from hydrogen isotope mixtures is of vital importance to develop nuclear energy industry, as well as other isotope-related advanced technologies. As...
Separating deuterium from hydrogen isotope mixtures is of vital importance to develop nuclear energy industry, as well as other isotope-related advanced technologies. As one of the most promising alternatives to conventional techniques for deuterium purification, kinetic quantum sieving using porous materials has shown a great potential to address this challenging objective. From the knowledge gained in this field; it becomes clear that a quantum sieve encompassing a wide range of practical features in addition to its separation performance is highly demanded to approach the industrial level. Here, the rational design of an ultra-microporous squarate pillared titanium oxide hybrid framework has been achieved, of which we report the comprehensive assessment towards practical deuterium separation. The material not only displays a good performance combining high selectivity and volumetric uptake, reversible adsorption-desorption cycles, and facile regeneration in adsorptive sieving of deuterium, but also features a cost-effective green scalable synthesis using chemical feedstock, and a good stability (thermal, chemical, mechanical and radiolytic) under various working conditions. Our findings provide an overall assessment of the material for hydrogen isotope purification and the results represent a step forward towards next generation practical materials for quantum sieving of important gas isotopes.
Topics: Deuterium; Adsorption; Biological Transport; Hydrogen
PubMed: 37443163
DOI: 10.1038/s41467-023-39871-x -
Chemistry (Weinheim An Der Bergstrasse,... Aug 2021In the field of medicinal chemistry, the precise installation of a trideuteromethyl group is gaining ever-increasing attention. Site-selective incorporation of the... (Review)
Review
In the field of medicinal chemistry, the precise installation of a trideuteromethyl group is gaining ever-increasing attention. Site-selective incorporation of the deuterated "magic methyl" group can provide profound pharmacological benefits and can be considered an important tool for drug optimization and development. This review provides a structured overview, according to trideuteromethylation reagent, of currently established methods for site-selective trideuteromethylation of carbon atoms. In addition to CD , the selective introduction of CD H and CDH groups is also considered. For all methods, the corresponding mechanism and scope are discussed whenever reported. As such, this review can be a starting point for synthetic chemists to further advance trideuteromethylation methodologies. At the same time, this review aims to be a guide for medicinal chemists, offering them the available C-CD formation strategies for the preparation of new or modified drugs.
Topics: Carbon; Deuterium; Indicators and Reagents
PubMed: 34076925
DOI: 10.1002/chem.202101179 -
Biochimica Et Biophysica Acta May 2000Various means of calculating the effect of changing the mass of a given atom upon a chemical process are reviewed. Of particular interest is the deuterium isotope effect... (Review)
Review
Various means of calculating the effect of changing the mass of a given atom upon a chemical process are reviewed. Of particular interest is the deuterium isotope effect comparing the normal protium nucleus with its heavier deuterium congener. The replacement of the bridging protium in a neutral hydrogen bond such as the water dimer by a deuterium strengthens the interaction by a small amount via effects upon the vibrational energy. In an ionic H-bond such as the protonated water dimer, on the other hand, the reverse trend is observed in that replacement of the bridging protium by dimer weakens the interaction. In addition to the stability of a given complex, the rate at which a proton transfers from one group to another is likewise affected by deuterium substitution, viz. kinetic isotope effects (KIEs). The KIE is enlarged as the temperature drops, particularly so if the calculation of KIE includes proton tunneling. The KIE is also sensitive to any angular distortions or stretches present in the H-bond of interest. KIEs can be computed either by the standard transition state theory which is derived via only two points on the potential energy surface, or by more complete formalisms which take account of larger swaths of the surface. While more time intensive, the latter can also be applied to provide insights important in interpretation of experimental data.
Topics: Deuterium; Energy Metabolism; Hydrogen; Hydrogen Bonding; Isotopes; Kinetics; Models, Theoretical; Proton-Motive Force; Protons; Temperature; Water
PubMed: 10812023
DOI: 10.1016/s0005-2728(00)00058-x -
International Journal of Molecular... Dec 2023We describe an investigation using structural mass spectrometry (MS) of the impact of two antibodies, 15497 and 15498, binding the highly flexible SARS-CoV-2 Nsp1...
We describe an investigation using structural mass spectrometry (MS) of the impact of two antibodies, 15497 and 15498, binding the highly flexible SARS-CoV-2 Nsp1 protein. We determined the epitopes and paratopes involved in the antibody-protein interactions by using hydrogen-deuterium exchange MS (HDX-MS). Notably, the Fab (Fragment antigen binding) for antibody 15498 captured a high energy form of the antigen exhibiting significant conformational changes that added flexibility over most of the Nsp1 protein. The Fab for antibody 15497, however, showed usual antigen binding behavior, revealing local changes presumably including the binding site. These findings illustrate an unusual antibody effect on an antigen and are consistent with the dynamic nature of the Nsp1 protein. Our studies suggest that this interaction capitalizes on the high flexibility of Nsp1 to undergo conformational change and be trapped in a higher energy state by binding with a specific antibody.
Topics: Humans; Deuterium; SARS-CoV-2; Deuterium Exchange Measurement; COVID-19; Mass Spectrometry; Proteins
PubMed: 38139170
DOI: 10.3390/ijms242417342 -
Molecules (Basel, Switzerland) Jun 2019Hydrodeaminated and monodeuterated aromatics were obtained via a visible-light driven reaction of arylazo sulfones. Deuteration occurs efficiently in deuterated media...
Hydrodeaminated and monodeuterated aromatics were obtained via a visible-light driven reaction of arylazo sulfones. Deuteration occurs efficiently in deuterated media such as isopropanol- or in THF-/water mixtures and exhibits a high tolerance to the nature and the position of the aromatic substituents.
Topics: Carbon-13 Magnetic Resonance Spectroscopy; Catalysis; Deamination; Deuterium; Hydrogen; Light; Metals; Proton Magnetic Resonance Spectroscopy; Sulfones
PubMed: 31181774
DOI: 10.3390/molecules24112164 -
Magnetic Resonance in Medicine Feb 2023Many MRS paradigms produce 2D spectral-temporal datasets, including diffusion-weighted, functional, and hyperpolarized and enriched (carbon-13, deuterium) experiments....
PURPOSE
Many MRS paradigms produce 2D spectral-temporal datasets, including diffusion-weighted, functional, and hyperpolarized and enriched (carbon-13, deuterium) experiments. Conventionally, temporal parameters-such as T , T , or diffusion constants-are assessed by first fitting each spectrum independently and subsequently fitting a temporal model (1D fitting). We investigated whether simultaneously fitting the entire dataset using a single spectral-temporal model (2D fitting) would improve the precision of the relevant temporal parameter.
METHODS
We derived a Cramer Rao lower bound for the temporal parameters for both 1D and 2D approaches for 2 experiments: a multi-echo experiment designed to estimate metabolite T s, and a functional MRS experiment designed to estimate fractional change ( ) in metabolite concentrations. We investigated the dependence of the relative standard deviation (SD) of T in multi-echo and in functional MRS.
RESULTS
When peaks were spectrally distant, 2D fitting improved precision by approximately 20% relative to 1D fitting, regardless of the experiment and other parameter values. These gains increased exponentially as peaks drew closer. Dependence on temporal model parameters was weak to negligible.
CONCLUSION
Our results strongly support a 2D approach to MRS fitting where applicable, and particularly in nuclei such as hydrogen and deuterium, which exhibit substantial spectral overlap.
Topics: Magnetic Resonance Spectroscopy; Deuterium; Diffusion
PubMed: 36121336
DOI: 10.1002/mrm.29456 -
Molecules (Basel, Switzerland) Apr 2013An extremely strong H/D isotope effect observed in hydrogen bonded A-H…B systems is connected with a reach diversity of the potential shape for the proton/deuteron... (Review)
Review
An extremely strong H/D isotope effect observed in hydrogen bonded A-H…B systems is connected with a reach diversity of the potential shape for the proton/deuteron motion. It is connected with the anharmonicity of the proton/deuteron vibrations and of the tunneling effect, particularly in cases of short bridges with low barrier for protonic and deuteronic jumping. Six extreme shapes of the proton motion are presented starting from the state without possibility of the proton transfer up to the state with a full ionization. The manifestations of the H/D isotope effect are best reflected in the infra-red absorption spectra. A most characteristic is the run of the relationship between the isotopic ratio nH/nD and position of the absorption band shown by using the example of NHN hydrogen bonds. One can distinguish a critical range of correlation when the isotopic ratio reaches the value of ca. 1 and then increases up to unusual values higher than . The critical range of the isotope effect is also visible in NQR and NMR spectra. In the critical region one observes a stepwise change of the NQR frequency reaching 1.1 MHz. In the case of NMR, the maximal isotope effect is reflected on the curve presenting the dependence of Δd (¹H,²H) on d (¹H). This effect corresponds to the range of maximum on the correlation curve between dH and ΔpKa that is observed in various systems. There is a lack in the literature of quantitative information about the influence of isotopic substitution on the dielectric properties of hydrogen bond except the isotope effect on the ferroelectric phase transition in some hydrogen bonded crystals.
Topics: Deuterium; Hydrogen Bonding; Isotopes; Magnetic Resonance Spectroscopy; Models, Chemical; Protons; Vibration
PubMed: 23591926
DOI: 10.3390/molecules18044467