Nucleoside analogs involving modifications in the carbohydrate ring: nuclear magnetic resonance spectroscopic studies

1985 ◽  
Vol 63 (8) ◽  
pp. 2162-2168 ◽  
Author(s):  
Walter A. Szarek ◽  
B. Mario Pinto ◽  
Masaharu Iwakawa
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Nucleoside Analogs ◽  
Spectroscopic Properties ◽  
Spectroscopic Studies ◽  
Nucleoside Analog ◽  
H Nmr ◽  
Acyclic Nucleoside ◽  
C Nmr

The concomitant use of 1H nmr and 13C nmr spectroscopy as a probe of structure, stereochemistry, and conformation of several nucleoside analogs derived from 1-oxa-4-thiacyclohexane is described. The 1H nmr spectroscopic properties of an acyclic nucleoside analog derived from uridine are also described.

Spectroscopic Studies on Pyrazaboles

1978 ◽  
Vol 33 (2) ◽  
pp. 220-223 ◽  
Author(s):  
C. E. May ◽  
K. Niedenzu ◽  
S. Trofimenko
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Mass Spectra ◽  
Spectroscopic Studies ◽  
Conformational Isomers ◽  
Magnetic Resonance Data ◽  
Resonance Data ◽  
C Nmr

The mass spectra of several pyrazaboles of type 1 where R and/or R′ = C2H5 have been studied. The loss of boron-bonded hydrocarbon moieties under electron impact is the predominant feature of all spectra. Some ultraviolet and nuclear magnetic resonance data on compounds of type 1 have been collected; bulky substituents were observed to lead to conformational isomers that can be detected by 13C NMR spectroscopy

scholarly journals Structural Characterization of Amadori Rearrangement Product of Glucosylated Nα-Acetyl-Lysine by Nuclear Magnetic Resonance Spectroscopy

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Chuanjiang Li ◽  
Hui Wang ◽  
Manuel Juárez ◽  
Eric Dongliang Ruan
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Maillard Reaction ◽  
Structural Characterization ◽  
Resonance Spectroscopy ◽  
H Nmr ◽  
Amadori Rearrangement ◽  
C Nmr ◽  
Nuclear Magnetic

Maillard reaction is a nonenzymatic reaction between reducing sugars and free amino acid moieties, which is known as one of the most important modifications in food science. It is essential to characterize the structure of Amadori rearrangement products (ARPs) formed in the early stage of Maillard reaction. In the present study, the Nα-acetyl-lysine-glucose model had been successfully set up to produce ARP, Nα-acetyl-lysine-glucose. After HPLC purification, ARP had been identified by ESI-MS with intense [M+H]+ ion at 351 m/z and the purity of ARP was confirmed to be over 90% by the relative intensity of [M+H]+ ion. Further structural characterization of the ARP was accomplished by using nuclear magnetic resonance (NMR) spectroscopy, including 1D 1H NMR and 13C NMR, the distortionless enhancement by polarization transfer (DEPT-135) and 2D 1H-1H and 13C-1H correlation spectroscopy (COSY) and 2D nuclear overhauser enhancement spectroscopy (NOESY). The complexity of 1D 1H NMR and 13C NMR was observed due to the presence of isomers in glucose moiety of ARP. However, DEPT-135 and 2D NMR techniques provided more structural information to assign the 1H and 13C resonances of ARP. 2D NOESY had successfully confirmed the glycosylated site between 10-N in Nα-acetyl-lysine and 7′-C in glucose.

Spectroscopic studies of N–S–O anions: The reactions of NSO− with elemental sulphur and with S4N4

1989 ◽  
Vol 67 (11) ◽  
pp. 1788-1794 ◽  
Author(s):  
Tristram Chivers ◽  
Kenneth J. Schmidt ◽  
Deane D. McIntyre ◽  
Hans J. Vogel
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Spectroscopic Studies ◽  
Major Product ◽  
Elemental Sulphur ◽  
Nuclear Magnetic

The reaction of (Me2N)3S+NSO− with sulphur has been investigated by ultraviolet–visible, infrared, Raman, and 14N, 17O, and 33S nuclear magnetic resonance spectroscopies. The red species (λmax 501 nm) formed initially is tentatively identified as SSNSO−. This anion is thermally unstable with respect to the formation of S4N− and sulphur oxyanions. Previously reported salts of the "NSO2−" ion have been reinvestigated by infrared, Raman, and 14N nmr spectroscopies, which indicate that the major component of these salts is the NSO− ion. The reaction of (Me2N)3S+NSO− with S4N4 is shown by 14N nmr spectroscopy to produce both S3N3O−, the major product, and S3N3−. Keywords: nitrogen–sulphur–oxygen (N–S–O) anions, 14N NMR spectroscopy.

Aliphatic diazo compounds. XIV. The synthesis of 7-substituted 3-diazo-2-norbornanones and the infrared and proton and carbon-13 nuclear magnetic resonance spectra of these diazo ketones and their precursors

1984 ◽  
Vol 62 (9) ◽  
pp. 1751-1766 ◽  
Author(s):  
Peter Yates ◽  
John David Kronis
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nmr Spectra ◽  
Diazo Compounds ◽  
Lower Field ◽  
Tert Butyl ◽  
H Nmr ◽  
Nuclear Magnetic Resonance Spectra ◽  
C Nmr ◽  
Shielding Effects

syn- and anti-7-Isopropyl-2-norbornanone (5 and 6) were prepared by catalytic hydrogenation of 7-isopropylidene-2-norbornanone; syn- and anti-7-benzhydryl-2-norbornane (9 and 10) were prepared in analogous fashion. Ketones 5 and 6 and syn- and anti-7-tert-butyl-2-norbornanone (7 and 8) were converted to the corresponding 3-diazo-2-norbornanones 1–4 via the monotosylhydrazones 44–47 of the corresponding α-diketones 40–43. The 1H and 13C nmr spectra of 1–10, 40–47, and their precursors have been analyzed. The 1H nmr spectra of the diazo ketones 1–4 have their C-1 and C-4 bridgehead proton signals shifted to higher and lower field, respectively, relative to the bridgehead signals of the corresponding diketones. The 13C nmr spectra of all pairs of bicyclic epimers shown γ-gauche shielding effects by the 7-substituent at (sp3) C-3 in the syn compounds and at C-5 and C-6 in the anti compounds. A converse effect is found at (sp2) C-2 (and C-3 in the diketones). Comparison of the magnitude of the shielding effects of C-7 methyl, isopropyl, benzhydryl, and tert-butyl substituents gives evidence of δ deshielding effects at C-3 in the syn compounds and at C-5 and C-6 in the anti compounds by methyl substituents on C-8.

scholarly journals 1H Nuclear Magnetic Resonance: A Future Approach to the Metabolic Profiling of Psychedelics in Human Biofluids?

2021 ◽  
Vol 12 ◽  
Author(s):  
Sylvana Vilca-Melendez ◽  
Malin V. Uthaug ◽  
Julian L. Griffin
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Metabolic Profiling ◽  
Proton Nuclear Magnetic Resonance ◽  
Future Directions ◽  
H Nmr ◽  
Nuclear Magnetic ◽  
Psychedelic Research

While psychedelics may have therapeutic potential for treating mental health disorders such as depression, further research is needed to better understand their biological effects and mechanisms of action when considering the development of future novel therapy approaches. Psychedelic research could potentially benefit from the integration of metabonomics by proton nuclear magnetic resonance (1H NMR) spectroscopy which is an analytical chemistry-based approach that can measure the breakdown of drugs into their metabolites and their metabolic consequences from various biofluids. We have performed a systematic review with the primary aim of exploring published literature where 1H NMR analysed psychedelic substances including psilocin, lysergic acid diethylamide (LSD), LSD derivatives, N,N-dimethyltryptamine (DMT), 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and bufotenin. The second aim was to assess the benefits and limitations of 1H NMR spectroscopy-based metabolomics as a tool in psychedelic research and the final aim was to explore potential future directions. We found that the most current use of 1H NMR in psychedelic research has been for the structural elucidation and analytical characterisation of psychedelic molecules and that no papers used 1H NMR in the metabolic profiling of biofluids, thus exposing a current research gap and the underuse of 1H NMR. The efficacy of 1H NMR spectroscopy was also compared to mass spectrometry, where both metabonomics techniques have previously shown to be appropriate for biofluid analysis in other applications. Additionally, potential future directions for psychedelic research were identified as real-time NMR, in vivo1H nuclear magnetic resonance spectroscopy (MRS) and 1H NMR studies of the gut microbiome. Further psychedelic studies need to be conducted that incorporate the use of 1H NMR spectroscopy in the analysis of metabolites both in the peripheral biofluids and in vivo to determine whether it will be an effective future approach for clinical and naturalistic research.

Synthesis of new 3H-chromeno[2,3-d]pyrimidine-4,6(5H,7H)-diones via the tandem intramolecular Pinner/Dimroth rearrangement

2018 ◽  
Vol 24 (1) ◽  
pp. 31-35 ◽  
Author(s):  
Nasrin Karimi ◽  
Abolghasem Davoodnia ◽  
Mehdi Pordel
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Proton Nuclear Magnetic Resonance ◽  
Phosphoryl Chloride ◽  
Dimroth Rearrangement ◽  
H Nmr ◽  
High Yields ◽  
Aliphatic Carboxylic Acids ◽  
C Nmr ◽  
Nuclear Magnetic

Abstract The reaction of 2-amino-4-aryl-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4H-chromene-3-carbonitriles with excess aliphatic carboxylic acids in the presence of phosphoryl chloride (POCl3) afforded new 2-alkyl-5-aryl-8,8-dimethyl-8,9-dihydro-3H-chromeno[2,3-d]pyrimidine-4,6(5H,7H)-diones in high yields. The suggested mechanism involves a tandem intramolecular Pinner/Dimroth rearrangement. The synthesized compounds were characterized by infrared (IR), proton nuclear magnetic resonance (1H NMR), carbon-13 nuclear magnetic resonance (13C NMR) and elemental analysis.

Ascorbic acid, a vitamin, is observed by in vivo13C nuclear magnetic resonance spectroscopy of rat liver

1998 ◽  
Vol 274 (1) ◽  
pp. E65-E71 ◽  
Author(s):  
Ekkehard Küstermann ◽  
Joachim Seelig ◽  
Basil Künnecke
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Ascorbic Acid ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Rat Liver ◽  
Whole Body ◽  
Resonance Spectroscopy ◽  
C Nmr ◽  
Nuclear Magnetic

The first in vivo detection of a vitamin with nuclear magnetic resonance (NMR) is reported for mammalian liver. Vitamin C, also known as ascorbic acid, was monitored noninvasively in rat liver by “whole body”13C NMR spectroscopy at high field after infusion of [1,2-13C2]glucose into anesthetized rats. Generally, the carbon resonances of ascorbic acid overlap with those of other highly abundant cellular metabolites, thus precluding their observation in situ. This problem was resolved by taking advantage of the13C-13C spin couplings introduced by the two covalently bound13C nuclei in [1,2-13C2]glucose. During glucose metabolism, [5,6-13C2]ascorbic acid was synthesized, which also exhibited characteristic13C homonuclear spin couplings. This feature enabled the spectral discrimination of ascorbic acid from overlapping singlet resonances of other metabolites. Quantitative analysis of the spin-coupling patterns provided an estimate of the turnover rate of hepatic ascorbic acid in vivo (1.9 ± 0.4 nmol ⋅ min−1 ⋅ g−1) and a novel approach toward a better understanding of optimal ascorbic acid requirements in humans. The results obtained in vivo were confirmed with high-resolution proton and13C NMR spectroscopy of liver extracts.

Serum analysis by1H Nuclear Magnetic Resonance spectroscopy: a new tool for distinguishing neuromyelitis optica from multiple sclerosis

2013 ◽  
Vol 20 (5) ◽  
pp. 558-565 ◽  
Author(s):  
F-M Moussallieh ◽  
K Elbayed ◽  
JB Chanson ◽  
G Rudolf ◽  
M Piotto ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Neuromyelitis Optica ◽  
Demyelinating Diseases ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
H Nmr ◽  
Nuclear Magnetic

Background:Neuromyelitis optica (NMO) and multiple sclerosis (MS), two inflammatory demyelinating diseases, are characterized by different therapeutic strategies. Currently, the only biological diagnostic tool available to distinguish NMO from MS is the specific serum autoantibody that targets aquaporin 4, but its sensitivity is low.Objective:To assess the diagnostic accuracy of metabolomic biomarker profiles in these two neurological conditions, compared to control patients.Methods:We acquired serum spectra (47 MS, 44 NMO and 42 controls) using proton nuclear magnetic resonance (1H-NMR) spectroscopy. We used multivariate pattern recognition analysis to identify disease-specific metabolic profiles.Results:The1H-NMR spectroscopic analysis evidenced two metabolites, originating probably from astrocytes, scyllo-inositol and acetate, as promising serum biomarkers of MS and NMO, respectively. In 87.8% of MS patients, scyllo-inositol increased 0.15 to 3-fold, compared to controls and in 74.3% of NMO patients, acetate increased 0.4 to 7-fold, compared to controls. Using these two metabolites simultaneously, we can discriminate MS versus NMO patients (sensitivity, 94.3%; specificity, 90.2%).Conclusion:This study demonstrates the potential of1H-NMR spectroscopy of serum as a novel, promising analytical tool to discriminate populations of patients affected by NMO or MS.

The structures and reactions of stannylene acetals from carbohydrate-derived trans-diols. Part I. In the absence of added nucleophiles

1990 ◽  
Vol 68 (7) ◽  
pp. 1007-1019 ◽  
Author(s):  
T. Bruce Grindley ◽  
Rasiah Thangarasa
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Magnetic Resonance Spectroscopy ◽  
Chemical Shifts ◽  
The Other ◽  
Resonance Spectroscopy ◽  
Pyranose Ring ◽  
Regioselective Reactions ◽  
C Nmr

Di-n-butylstannylene acetals of benzyl 4,6-O-benzylidene-α- and -β-D-glucopyranoside and galactopyranoside have been prepared and studied in solution by 1H, 13C, and 119Sn nuclear magnetic resonance spectroscopy. The species present in solution have been identified from the 119Sn nmr spectral data, by comparison of the 13C nmr chemical shifts of the stannylene acetals and their precursor diols and also by analysis of the products of reactions performed without added nucleophiles. The orientations of the two substituents on the carbons in the pyranose ring attached to the carbons in the stannylene ring determine the structures adopted by the stannylene acetal in solution. If one substituent is axial and the other equatorial, the stannylene acetal exists as a single symmetrical dimer in which the two oxygen atoms in the two 1,3,2-dioxastannolane rings adjacent to the axial substituents are dicoordinate. A stannylene acetal with two adjacent equatorial substituents exists as a non-interconverting mixture of dimers; one with two adjacent axial substituents is present as a rapidly interconverting mixture of dimers, trimers, and tetramers. Benzoylation and benzylation of the latter two types of stannylene acetals have been performed and have been shown to be only slightly regioselective in contrast to the known highly regioselective reactions of the first type. Only when single dimers are present are regiospecific or highly regioselective reactions obtained. The causes of the variation in the species present and of the reaction regioselectivity for different stannylene acetals are discussed. Keywords: stannylene acetals, 1,3,2-dioxastannolanes, 119Sn NMR spectroscopy, regioselective reactions, carbohydrates.

scholarly journals Metabolomics comparison of rumen fluid and milk in dairy cattle using proton nuclear magnetic resonance spectroscopy

2021 ◽  
Vol 34 (2) ◽  
pp. 213-222
Author(s):  
Jun Sik Eom ◽  
Eun Tae Kim ◽  
Hyun Sang Kim ◽  
You Young Choi ◽  
Shin Ja Lee ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Magnetic Resonance ◽  
Dairy Cattle ◽  
Metabolic Diseases ◽  
Rumen Fluid ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
H Nmr ◽  
Nuclear Magnetic

Objective: The metabolites that constitute the rumen fluid and milk in dairy cattle were analyzed using proton nuclear magnetic resonance (<sup>1</sup>H-NMR) spectroscopy and compared with the results obtain for other dairy cattle herds worldwide. The aim was to provide basic dataset for facilitating research on metabolites in rumen fluid and milk.Methods: Six dairy cattle were used in this study. Rumen fluid was collected using a stomach tube, and milk was collected using a pipeline milking system. The metabolites were determined by <sup>1</sup>H-NMR spectroscopy, and the obtained data were statistically analyzed by principal component analysis, partial least squares discriminant analysis, variable importance in projection scores, and metabolic pathway data using Metaboanalyst 4.0.Results: The total numbers of metabolites in rumen fluid and milk were measured to be 186 and 184, and quantified as 72 and 109, respectively. Organic acid and carbohydrate metabolites exhibited the highest concentrations in rumen fluid and milk, respectively. Some metabolites that have been associated with metabolic diseases (acidosis and ketosis) in cows were identified in rumen fluid, and metabolites associated with ketosis, somatic cell production, and coagulation properties were identified in milk.Conclusion: The metabolites measured in rumen fluid and milk could potentially be used to detect metabolic diseases and evaluate milk quality. The results could also be useful for metabolomic research on the biofluids of ruminants in Korea, while facilitating their metabolic research.

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