ChemInform Abstract: pH Dependence of the Stability of Boric Acid and Borate Esters of Amino Acids and Amino Diols in Aqueous Medium as Studied by 11B and 1H NMR Spectroscopy.

ChemInform ◽  
1989 ◽  
Vol 20 (37) ◽  
Author(s):  
J. VAN HAVEREN ◽  
J. A. PETERS ◽  
J. G. BATELAAN ◽  
A. P. G. KIEBOOM ◽  
H. VAN BEKKUM
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
Boric Acid ◽  
Aqueous Medium ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Ph Dependence ◽  
Borate Esters ◽  
The Stability

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 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.

scholarly journals CRYSTAL STRUCTURE AND TAUTOMERISM OF ALKYLAMINO-β-KETOENOLS IN SOLUTIONS

2019 ◽  
Vol 85 (8) ◽  
pp. 73-82
Author(s):  
VIKTOR CHERNII
Keyword(s):  
Mass Spectrometry ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Trifluoroacetic Acid ◽  
1H Nmr Spectroscopy ◽  
Keto Group ◽  
Polymethine Chain ◽  
X Ray Diffraction ◽  
The Stability ◽  
Crystalline System

The structure of alkylamino-β-ketoenols obtained by opening of the pyran cycle of chalcones based on dehydracetic acid was studied by X-ray diffraction, IR, 1H NMR spectroscopy and chromatography-mass spectrometry. The infrared spectra of the compounds appear to be typical of β-ketoenols. The crystalline structure (2Z,5Z,7E,9E)-6-hydroxy-2-(methylami-no)-10-phenylethoxy-2,5,7,9-tetraene-4-one was first determined. A comparative analysis of it with 2 pre-viously published structures has been carried out. All of these compounds are crystallized in the form of yellow plates in the monoclinic crystalline system (spatial group P21/n), they have a planar arrangement of the polyene chain and β-ketoenol fragment con-jugated to the aromatic ring. It has been established that the planar configuration of the β-ketoenol fragment is stabilized by hydrogen bonds between the hydroxy and keto group and the amino and keto group in the crystalline state. The length of the polymethine chain, the nature of the substituents in the aromatic and aliphatic part of the molecule do not significantly affect the size and geometry of the alkylamino-β-ketoenolate fragment. Approximately the same lengths of bonds, the distance between atoms and the corners indicate that all these com-pounds may have similar chelating properties. Ac-cording to 1H NMR spectroscopy in various deu-terated solvents (benzene, DMSO, chloroform, ace-tone, methanol and trifluoroacetic acid), most of the main signals of the obtained compounds have sa-tellites, which indicates the existence of several isomeric forms in solutions. The analysis of integral intensities of labile protons in 1H NMR spectra does not allow to obtain accurate results regarding the ratio of tautomers in a solution, but for a series of compounds their approximate ratio in chloroform, DMSO and trifluoroacetic acid have been established (from 70:30 in CDCl3 to 90:10 in DMSO and CF3CO2D). The stability of the tautomers in the solutions is confirmed by the data of chromatogra-phy-mass spectrometry.

scholarly journals 1H NMR spectroscopy reveals that mouse Hsp25 has a flexible C-terminal extension of 18 amino acids

FEBS Letters ◽  
1995 ◽  
Vol 369 (2-3) ◽  
pp. 305-310 ◽  
Author(s):  
John A. Carver ◽  
Gennaro Esposito ◽  
Gabriele Schwedersky ◽  
Matthias Gaestel
Keyword(s):  
Amino Acids ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy

Hydrogenolysis of glycerol in aqueous medium over Pt/WO3/zirconium phosphate catalysts studied by 1H NMR spectroscopy

2021 ◽  
Author(s):  
Susmita Bhowmik ◽  
Nagasuresh Enjamuri ◽  
Srinivas Darbha
Keyword(s):  
Nmr Spectroscopy ◽  
Liquid Phase ◽  
Aqueous Medium ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Zirconium Phosphate ◽  
Solvent Suppression

Bifunctional Pt/WO3/zirconium phosphate catalyzes the liquid-phase hydrogenolysis of glycerol in aqueous medium. 1H NMR spectroscopy (solvent suppression pulse program) is employed to monitor this reaction. Propanediols (1,3 + 1,2-PDO) formed...

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