scholarly journals Fast profiling of metabolite mixtures using chemometric analysis of a speeded-up 2D heteronuclear correlation NMR experiment

RSC Advances ◽  
2017 ◽  
Vol 7 (47) ◽  
pp. 29860-29870 ◽  
Author(s):  
Rakesh Sharma ◽  
Navdeep Gogna ◽  
Harpreet Singh ◽  
Kavita Dorai
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Chemometric Analysis ◽  
Two Dimensional ◽  
Metabolite Fingerprinting ◽  
Heteronuclear Correlation ◽  
One Dimensional

One-dimensional (1D) NMR spectra of mixtures of metabolites suffer from severe overlap of spectral resonances and hence recent research in NMR-based metabolomics focuses on using two-dimensional (2D) NMR experiments for metabolite fingerprinting.

scholarly journals New 3-Hydroxyquinaldic Acid Derivatives from Cultures of the Marine Derived Actinomycete Streptomyces cyaneofuscatus M-157

Marine Drugs ◽  
2018 ◽  
Vol 16 (10) ◽  
pp. 371 ◽  
Author(s):  
Francisco Ortiz-López ◽  
Elsa Alcalde ◽  
Aida Sarmiento-Vizcaíno ◽  
Caridad Díaz ◽  
Bastien Cautain ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
2D Nmr ◽  
Two Dimensional ◽  
Amino Acid Residues ◽  
Trace Level ◽  
One Dimensional ◽  
2D Nmr Spectra ◽  
Ic50 Values ◽  
New Compounds ◽  
Tof Ms

Fractionation of the bioactive extract of a culture of the marine derived actinomycete Streptomyces cyaneofuscatus M-157 led to the isolation of the known 3-hydroxyquinaldic acid (4), its amide (5) and three new derivatives (1–3) containing different amino acid residues. The structures of the new molecules (1–3), including their absolute configuration, were determined by the analysis of their ESI-TOF MS and one-dimensional (1D) and two-dimensional (2D) NMR spectra and advanced Marfey’s analysis of their hydrolyzation products. Compound 3 spontaneously dimerized in solution to give the disulfide derivative 6. Unfortunately, none of the new compounds isolated confirmed the antimicrobial activity found in the bacterial extract, perhaps indicating that such antibacterial activity might be due to presence in the extract at the trace level of larger bioactive 3-hydroxyquinaldic acid derivatives from which compounds 1–3 are biosynthetic precursors. Cytotoxicity tests confirmed the moderate and weak IC50 values of 15.6 and 51.5 µM for compounds 5 and 1, respectively.

scholarly journals A New Chlorinated Phenolic Compound From the Antarctic Lichen, Pertusaria dactylina

2020 ◽  
Vol 15 (3) ◽  
pp. 1934578X2090288
Author(s):  
Man H. Koo ◽  
Min J. Kim ◽  
Jae E. Seo ◽  
Ji H. Kim ◽  
Se J. Han ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Phenolic Compound ◽  
Fast Atom Bombardment ◽  
2D Nmr ◽  
Antimicrobial Activities ◽  
Inhibitory Effect ◽  
Two Dimensional ◽  
One Dimensional ◽  
The Antarctic

A new chlorinated phenolic compound, methyl-3-chloro-2-hydroxy-4-methoxy-6-pentylbenzoate (1) and 4 known compounds (2-5) were isolated from the Antarctic lichen, Pertusaria dactylina ( Pertusariaceae). The structure of the new compound was determined by means of One-dimensional and two dimensional nuclear magnetic resonance (1D and 2D NMR) and high-resolution fast atom bombardment mass spectrometry (HRFABMS) experiments. The antimicrobial activities of compounds 1 to 5 against Staphylococcus aureus and Candida albicans were evaluated. The results showed that compound 1 exhibited a weak inhibitory effect against C. albicans with an IC50 value of 67 ± 7 μg/mL.

scholarly journals Two New Spiro-Heterocyclic γ-Lactams from A Marine-Derived Aspergillus fumigatus Strain CUGBMF170049

Marine Drugs ◽  
2019 ◽  
Vol 17 (5) ◽  
pp. 289 ◽  
Author(s):  
Xiuli Xu ◽  
Jiahui Han ◽  
Yanan Wang ◽  
Rui Lin ◽  
Haijin Yang ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Circular Dichroism ◽  
Aspergillus Fumigatus ◽  
2D Nmr ◽  
Two Dimensional ◽  
One Dimensional ◽  
Helvolic Acid ◽  
Circular Dichroïsm

Two new spiro-heterocyclic γ-lactam derivatives, cephalimysins M (1) and N (2), were isolated from the fermentation cultures of the marine-derived fungus Aspergillus fumigatus CUGBMF17018. Two known analogues, pseurotin A (3) and FD-838 (4), as well as four previously reported helvolic acid derivatives, 16-O-propionyl-16-O-deacetylhelvolic acid (5), 6-O-propionyl-6-O-deacetylhelvolic acid (6), helvolic acid (7), and 1,2-dihydrohelvolic acid (8) were also identified. One-dimensional (1D), two-dimensional (2D) NMR, HRMS, and circular dichroism spectral analysis characterized the structures of the isolated compounds.

scholarly journals Synthesis, Fluorescence and NMR Spectroscopic Studies of a Novel Phosphinoxido-18-crown-6 Ether Containing an Anthracene Fluorophore Unit

2019 ◽  
Vol 64 (1) ◽  
pp. 37-45 ◽  
Author(s):  
Hajnalka Szabó-Szentjóbi ◽  
Anna Márton ◽  
Dávid Pál ◽  
Gergő Dargó ◽  
Áron Szigetvári ◽  
...  
Keyword(s):  
Nmr Spectra ◽  
Spectroscopic Studies ◽  
Primary Amines ◽  
Methyl Groups ◽  
Amino Acid Esters ◽  
Two Dimensional ◽  
Fluorescent Chemosensors ◽  
One Dimensional ◽  
Stereogenic Centers ◽  
Acid Esters

The synthesis of the (R,R) and (S,S) enantiomers of a new enantiopure monophospha-18-crown-6 ether (1), which contains an anthracene fluorophore unit and methyl groups at its stereogenic centers, was accomplished. The structure of one enantiomer ((S,S)-1) was studied using one-dimensional (1H, 13C{1H}, and 31P{1H}) and two-dimensional NMR spectra. Because (R,R)-1 and (S,S)-1 can act as new fluorescent chemosensors, we examined their enantiomeric differentiation abilities toward the enantiomers of protonated chiral primary amines and amino acid esters (PEA, 1-NEA, PGME, PAME) using UV-Vis and fluorescence spectroscopies. These monophospha-crown ethers showed moderate enantiomeric discrimination abilities.

scholarly journals Fluorescence Assay for the Determination of d-Panthenol Based on Novel Ring-Fused 2-Pyridone Derivative

2020 ◽  
Vol 21 (21) ◽  
pp. 8386
Author(s):  
Wiktor Kasprzyk ◽  
Tomasz Świergosz ◽  
Filip Koper
Keyword(s):  
Citric Acid ◽  
Nmr Spectra ◽  
Chemical Structure ◽  
Accurate Determination ◽  
Pharmaceutical Formulations ◽  
Two Dimensional ◽  
One Dimensional ◽  
Fluorescent Method ◽  
Derivatizing Agent

Herein, a novel fluorescent method for the determination of d-panthenol (DP) level in solutions with no separate hydrolysis step has been revealed based on the utilization of citric acid (CA) as a derivatizing agent. Consequently, the essential parameters of the derivatization process were established, resulting in the development of sensitive, repeatable, and accurate determination of panthenol. The method was approved, and its usefulness in characterizing the concentration of DP in pharmaceutical formulations and selectivity in the determination of DP were validated. The chemical structure of the new fluorophore formulating in the reaction in DP with CA, i.e., 6-oxo-3,4-dihydro-2H,6H-pyrido[2,1-b][1,3]oxazine-8-carboxylic acid (ODPC), was elucidated using detailed NMR experiments: one-dimensional (1H, 13C) as well as two-dimensional NMR spectra (1H-1H COSY, 1H-13C HSQC, 1H-13C HMBC, 1H-15N HSQC, 1H-15N HMBC).

scholarly journals Identification of Lignin and Polysaccharide Modifications in Populus Wood by Chemometric Analysis of 2D NMR Spectra from Dissolved Cell Walls

2009 ◽  
Vol 2 (5) ◽  
pp. 933-942 ◽  
Author(s):  
Mattias Hedenström ◽  
Susanne Wiklund-Lindström ◽  
Tommy Öman ◽  
Fachuang Lu ◽  
Lorenz Gerber ◽  
...  
Keyword(s):  
Cell Walls ◽  
Nmr Spectra ◽  
2D Nmr ◽  
Chemometric Analysis ◽  
2D Nmr Spectra

scholarly journals Cross-Peaks in Simple 2D NMR Experiments from Chemical Exchange of Transverse Magnetization

2019 ◽  
Author(s):  
Chris Waudby ◽  
Tom Frenkiel ◽  
John Christodoulou
Keyword(s):  
Chemical Shift ◽  
Chemical Exchange ◽  
Exchange Process ◽  
2D Nmr ◽  
Two Dimensional ◽  
One Dimensional ◽  
Exchange Processes ◽  
Rich Information ◽  
Multiple Chemical

Two-dimensional correlation measurements such as COSY, NOESY, HMQC and HSQC experiments are central to small molecule and biomolecular NMR spectroscopy, and commonly form the basis of more complex experiments designed to study chemical exchange occurring during additional mixing periods. However, exchange occurring during chemical shift evolution periods can also influence the appearance of such spectra. While this is often exploited through one-dimensional lineshape analysis ('dynamic NMR'), the analysis of exchange across multiple chemical shift evolution periods has received less attention. Here we report that chemical exchange-induced cross-peaks can arise in even the simplest two-dimensional NMR experiments. These cross-peaks can have highly distorted phases that contain rich information about the underlying exchange process. The quantitative analysis of such peaks, from a single 2D spectrum, can provide a highly accurate characterization of underlying exchange processes.

Two single-enantiomer amidophosphoesters: a database study on the chirality of (O)2P(O)(N)-based structures

2019 ◽  
Vol 75 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Fahimeh Sabbaghi ◽  
Mehrdad Pourayoubi ◽  
Marek Nečas ◽  
Krishnan Damodaran
Keyword(s):  
Hydrogen Bond ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Two Dimensional ◽  
One Dimensional ◽  
Space Groups ◽  
Structural Database ◽  
Graph Set ◽  
Hydrogen Bonded

The crystal structures of two single-enantiomer amidophosphoesters with an (O)2P(O)(N) skeleton, i.e. diphenyl [(R)-(+)-α-methylbenzylamido]phosphate, (I), and diphenyl [(S)-(−)-α-methylbenzylamido]phosphate, (II), both C20H20NO3P, are reported. In both structures, chiral one-dimensional hydrogen-bonded architectures, along [010], are mediated by N—H...OP interactions. The statistically identical assemblies include the noncentrosymmetric graph-set motif C(4) and the compounds crystallize in the chiral space group P21. As a result of synergistic co-operation from C—H...O interactions, a two-dimensional superstructure is built including a noncentrosymmetric R 4 4(22) hydrogen-bonded motif. A Cambridge Structural Database survey was performed on (O)2P(O)(N)-based structures in order to review the frequency of space groups observed in this family of compounds; the hydrogen-bond motifs in structures with chiral space groups and the types of groups inducing chirality are discussed. The 2,3 JX –P (X = H or C) coupling constants from the NMR spectra of (I) and (II) have been studied. In each compound, the two diastereotopic C6H5O groups are different, which is reflected in the different chemical shifts and some coupling constants.

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