scholarly journals Chiral discrimination of α-hydroxy acids and N-Ts-α-amino acids induced by tetraaza macrocyclic chiral solvating agents by using 1H NMR spectroscopy

2017 ◽  
Vol 15 (7) ◽  
pp. 1642-1650 ◽  
Author(s):  
Caixia Lv ◽  
Lei Feng ◽  
Hongmei Zhao ◽  
Guo Wang ◽  
Pericles Stavropoulos ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Chiral Discrimination ◽  
Hydroxy Acids ◽  
H Nmr

Several α-hydroxy acids and N-Ts-α-amino acids were effectively discriminated in the presence of tetraaza macrocyclic chiral solvating agents (TAMCSAs) 1a–1d by 1H NMR spectroscopy.

Conformational study on ribonucleoside O-phosphonylmethyl derivatives by 1H NMR spectroscopy

1985 ◽  
Vol 50 (8) ◽  
pp. 1899-1905 ◽  
Author(s):  
Milena Masojídková ◽  
Jaroslav Zajíček ◽  
Miloš Buděšínský ◽  
Ivan Rosenberg ◽  
Antonín Holý
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Conformational Study ◽  
H Nmr ◽  
Conformational Properties

Conformational properties of ribonucleoside 5'-O-phosphonylmethyl derivatives have been determined by 1H NMR spectroscopy and compared with those of natural nucleosides and 5'-nucleotides.

Discrimination of Enantiomers of Amides with Two Stereogenic Centers Enabled by Chiral Bisthiourea Derivatives Using 1H NMR Spectroscopy

2021 ◽  
Author(s):  
Hanchang Zhang ◽  
Hongmei Zhao ◽  
Jie Wen ◽  
Zhanbin Zhang ◽  
Pericles Stavropoulos ◽  
...  
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Chiral Recognition ◽  
Stereogenic Centers

Enantiomers of a few new amides containing two stereogenic centers have been derived from D- and L-α-amino acids as guests for chiral recognition by 1H NMR spectroscopy. A variety of...

scholarly journals Assessment of 1H NMR Spectroscopy for Specific Metabolite Fingerprinting of Angelica sinensis

2008 ◽  
Vol 3 (5) ◽  
pp. 1934578X0800300
Author(s):  
Dongmin Su ◽  
Jinglan Han ◽  
Shishan Yu ◽  
Hailin Qin
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Authentic Sample ◽  
Angelica Sinensis ◽  
Metabolite Fingerprinting ◽  
H Nmr ◽  
Pure Compounds ◽  
Polar Extracts

The 1H NMR fingerprints of fractionated non-polar extracts (CSPD A) from the roots of Angelica sinensis of six different specimens were assigned by comparison with the 1H NMR spectra of the isolated pure compounds. The 1H NMR fingerprints showed exclusively characteristic resonance signals of the major constituents of the plant. The 1H NMR fingerprint established for an authentic sample of A. sinensis can be used for authenticating A. sinensis species.

Low-field 1H-NMR spectroscopy for compositional analysis of multicomponent polymer systems

The Analyst ◽  
2019 ◽  
Vol 144 (5) ◽  
pp. 1679-1686 ◽  
Author(s):  
Sneha B. Chakrapani ◽  
Michael J. Minkler ◽  
Bryan S. Beckingham
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Compositional Analysis ◽  
Polymer Systems ◽  
H Nmr ◽  
Low Field ◽  
Multicomponent Polymer

A low-field, 60 MHz, 1H NMR spectrometer yields quantitatively comparable results to 400 MHz spectrometers for the compositional analysis of multicomponent polymer systems.

Light induced E–Z isomerization in a multi-responsive organogel: elucidation from 1H NMR spectroscopy

2015 ◽  
Vol 51 (53) ◽  
pp. 10680-10683 ◽  
Author(s):  
Sanjoy Mondal ◽  
Priyadarshi Chakraborty ◽  
Partha Bairi ◽  
Dhruba P. Chatterjee ◽  
Arun K. Nandi
Keyword(s):  
Mechanical Properties ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Nmr Spectra ◽  
H Nmr ◽  
Imine Bond

Light induced E–Z isomerization along imine bond in a multiresponsive organogel of anthracene attached 3,4,5-tris(dodecyloxy)benzohydrazide gelator altering morphology, fluorescence and mechanical properties is elucidated from 1H NMR spectra.

scholarly journals Aromatic amino acids play a harmonizing role in prostate cancer: A metabolomics-based cross-sectional study

2021 ◽  
pp. 741-750
Author(s):  
Ziba Akbari ◽  
Roghayeh Taghipour Dijojin ◽  
Zahra Zamani ◽  
Reza Haji Hosseini ◽  
Mohammad Arjmand
Keyword(s):  
Prostate Cancer ◽  
Amino Acids ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Aromatic Amino Acids ◽  
Proton Nuclear Magnetic Resonance ◽  
Least Squares Regression ◽  
Cross Sectional ◽  
Metabolomics Data

Background: Prostate cancer (PCa) is a common health problem worldwide. The rate of this disease is likely to grow by 2021. PCa is a heterogeneous disorder, and various biochemical factors contribute to the development of this disease. The metabolome is the complete set of metabolites in a cell or biological sample and represents the downstream end product of the omics. Hence, to model PCa by computational systems biology, a preliminary metabolomics-based study was used to compare the metabolome profile pattern between healthy and PCa men. Objective: This study was carried out to highlight energy metabolism modification and assist the prognosis and treatment of disease with unique biomarkers. Materials and Methods: In this cross-sectional research, 26 men diagnosed with stage-III PCa and 26 healthy men with normal PSA levels were enrolled. Urine was analyzed with proton nuclear magnetic resonance (1H-NMR) spectroscopy, accompanied by the MetaboAnalyst web-based platform tool for metabolomics data analysis. Partial least squares regression discriminant analysis was applied to clarify the separation between the two groups. Outliers were documented and metabolites determined, followed by identifying biochemical pathways. Results: Our findings reveal that modifications in aromatic amino acid metabolism and some of their metabolites have a high potential for use as urinary PCa biomarkers. Tryptophan metabolism (p < 0.001), tyrosine metabolism (p < 0.001), phenylalanine, tyrosine and tryptophan biosynthesis (p < 0.001), phenylalanine metabolism (p = 0.01), ubiquinone and other terpenoid-quinone biosynthesis (p = 0.19), nitrogen metabolism (p = 0.21), and thiamine metabolism (p = 0.41) with Q2 (0.198) and R2 (0.583) were significantly altered. Conclusion: The discriminated metabolites and their pathways play an essential role in PCa causes and harmony. Key words: Metabolomics, Prostate cancer, Aromatic amino acids, 1H-NMR spectroscopy.

scholarly journals Branched-Chain Amino Acids Can Predict Mortality in ICU Sepsis Patients

Nutrients ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 3106
Author(s):  
Alexander Christian Reisinger ◽  
Florian Posch ◽  
Gerald Hackl ◽  
Gunther Marsche ◽  
Harald Sourij ◽  
...  
Keyword(s):  
Amino Acids ◽  
Septic Shock ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Outcome Prediction ◽  
Branched Chain Amino Acids ◽  
Proton Nuclear Magnetic Resonance ◽  
Branched Chain ◽  
And Control

Sepsis biomarkers and potential therapeutic targets are urgently needed. With proton nuclear magnetic resonance (1H NMR) spectroscopy, several metabolites can be assessed simultaneously. Fifty-three adult medical ICU sepsis patients and 25 ICU controls without sepsis were prospectively enrolled. 1H NMR differences between groups and associations with 28-day and ICU mortality were investigated. In multivariate metabolomic analyses, we found separate clustering of ICU controls and sepsis patients, as well as septic shock survivors and non-survivors. Lipoproteins were significantly different between sepsis and control patients. Levels of the branched-chain amino acids (BCAA) valine (median 43.3 [29.0–53.7] vs. 64.3 [47.7–72.3] normalized signal intensity units; p = 0.005), leucine (57.0 [38.4–71.0] vs. 73.0 [54.3–86.3]; p = 0.034) and isoleucine (15.2 [10.9–21.6] vs. 17.9 [16.1–24.4]; p = 0.048) were lower in patients with septic shock compared to those without. Similarly, BCAA were lower in ICU non-survivors compared to survivors, and BCAA were good discriminators for ICU and 28-day mortality. In uni- and multivariable logistic regression analyses, higher BCAA levels were associated with decreased ICU- and 28-day mortality. In conclusion, metabolomics using 1H NMR spectroscopy showed encouraging potential for personalized medicine in sepsis. BCAA was significantly lower in sepsis non-survivors and may be used as early biomarkers for outcome prediction.

Conformation studies of isomeric 1-acyloxy-2-(4-methoxybenzyl)-cyclohexanes by 1H NMR spectroscopy

1982 ◽  
Vol 47 (10) ◽  
pp. 2763-2767 ◽  
Author(s):  
Miloš Buděšínský ◽  
David Šaman ◽  
Zdeněk Wimmer
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Chair Conformation ◽  
Acetoxy Group ◽  
Cyclohexane Ring ◽  
H Nmr

The conformation of the cyclohexane ring and the p-methoxybenzyl substituent in the series of isomeric 1-acyloxy-2-(4-methoxybenzyl)cyclohexanes was studied by means of 1H NMR spectroscopy. In all the substances investigated the cyclohexane ring assumes chair conformation. trans-Isomers have both substituents in equatorial positions, while in cis-isomers the p-methoxybenzyl group is always equatorial and the hydroxy or acetoxy group axial.

scholarly journals (—)D-und (+)D-4-Methoxyphenylmethyl- thiophosphinsäure, Überprüfung der Racematspaltung mittels 31P{ 1H}-NMR-Spektroskopie/(—)D-and (+ )D-4-Methoxyphenylmethyl- thiophosphinic Acid, Control of the Resolution by 31P{1H} NMR Spectroscopy

1979 ◽  
Vol 34 (9) ◽  
pp. 1332-1333 ◽  
Author(s):  
Wilhelm Kuchen ◽  
Jurgen Kutter
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Fractional Crystallization ◽  
1H Nmr Spectroscopy ◽  
Optical Purity ◽  
Separation Process ◽  
H Nmr ◽  
Acid Control

Abstract (-)D-and (+)D-4-methoxyphenylmethyl-thiophosphinic acid, quinine salts of (-)D-and (+)D-4-methoxyphenylmethylthiophosphinic acid, checking of resolution by 31P{ 1H} NMR-spectroscopy (-)D-and(+)D-4-CH3OC6H4(CH3)P(S)OH acid were obtained from fractional crystallization of the quinine salt of the racemic acid. 31P{1H} NMR spectroscopy proved to be very useful in checking the separation process as well as the optical purity of the diastereomers and enan­tiomers.

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