One-dimensional 13C NMR and HPLC-1H NMR techniques for observing carbon-13 and deuterium labelling in biosynthetic studies

2003 ◽  
Vol 2 (1-2) ◽  
pp. 31-43 ◽  
Author(s):  
Bernd Schneider ◽  
Jonathan Gershenzon ◽  
Gerson Graser ◽  
Dirk Hölscher ◽  
Bettina Schmitt
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Deuterium Labelling ◽  
One Dimensional ◽  
Nmr Techniques ◽  
Biosynthetic Studies

scholarly journals One-Dimensional 13C NMR Is a Simple and Highly Quantitative Method for Enantiodiscrimination

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1785 ◽  
Author(s):  
Peter Lankhorst ◽  
Jozef van Rijn ◽  
Alexander Duchateau
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Quantitative Method ◽  
Enantiomeric Excess ◽  
Nmr Spectrum ◽  
One Dimensional ◽  
Nmr Method ◽  
Relative Standard ◽  
Excess Value ◽  
Chiral Solvating Agent

The discrimination of enantiomers of mandelonitrile by means of 1D 13C NMR and with the aid of the chiral solvating agent (S)-(+)-1-(9-anthryl)-2,2,2-trifluoroethanol (TFAE) is presented. 1H NMR fails for this specific compound because proton signals either overlap with the signals of the chiral solvating agent or do not show separation between the (S)-enantiomer and the (R)-enantiomer. The 13C NMR method is validated by preparing artificial mixtures of the (R)-enantiomer and the racemate, and it is shown that with only 4 mg of mandelonitrile a detection limit of the minor enantiomer of 0.5% is obtained, corresponding to an enantiomeric excess value of 99%. Furthermore, the method shows high linearity, and has a small relative standard deviation of only 0.3% for the minor enantiomer when the relative abundance of this enantiomer is 20%. Therefore, the 13C NMR method is highly suitable for quantitative enantiodiscrimination. It is discussed that 13C NMR is preferred over 1H NMR in many situations, not only in molecules with more than one chiral center, resulting in complex mixtures of many stereoisomers, but also in the case of molecules with overlapping multiplets in the 1H NMR spectrum, and in the case of molecules with many quaternary carbon atoms, and therefore less abundant protons.

scholarly journals Phytochemical screening of Colocasia gigantea and Colocasia affinis (Family: Araceae) using 1H-NMR and 13C-NMR techniques

2020 ◽  
Author(s):  
Safaet Alam ◽  
Mohammad Rashedul Haque
Keyword(s):  
Stearic Acid ◽  
1H Nmr ◽  
13C Nmr ◽  
Ornamental Plant ◽  
Phytochemical Screening ◽  
Separation Techniques ◽  
H Nmr ◽  
The World ◽  
Nmr Techniques ◽  
C Nmr

AbstractColocasia affinis and Colocasia gigantea are two of commonly found species under Colocasia genus. Folkloric use of these plants ascertains their ethnopharmacological importance and these plants are eaten as vegetables in several regions all around the world while Colocasia gigantea has planted as an ornamental plant too. Phytochemical screening of dichloromethane fractions of these plants using several separation techniques along followed by 1H-NMR and 13C-NMR techniques provide flavonoids and some other phyto compounds. However, in total 7 compounds were isolated from these plants i.e. penduletin (1), 7,8 -(3”,3”-dimethyl-pyrano)-4’-hydroxy flavonol (2), mixture of 7,8 -(3’’,3’’-dimethyl-pyrano)-4’-hydroxy flavonol from C. affinis and mixture of α-amyrin and β-amyrin (3), penduletin (5), monoglyceride of stearic acid (6) from C. gigantea.

scholarly journals Synthesis and complete NMR spectral assignments of new benzylamino coumarin derivative

2020 ◽  
Vol 10 (2) ◽  
pp. 12-16
Author(s):  
Vidoslav Dekić ◽  
Niko Radulović ◽  
Milenko Ristić ◽  
Biljana Dekić ◽  
Novica Ristić
Keyword(s):  
Spectral Analysis ◽  
Ethyl Acetate ◽  
1H Nmr ◽  
Resonance Assignment ◽  
13C Nmr ◽  
Spatial Orientation ◽  
Good Yield ◽  
Coumarin Derivative ◽  
Two Dimensional ◽  
Nmr Techniques

This research involves the reaction of 4-chloro-3-nitrocoumarin and (4-methoxyphenyl)methanamine, whereby a novel coumarin derivative 4-[(4-methoxybenzyl) amino]-3-nitro-2H-chromen-2-one was obtained in good yield. The reaction was carried out in ethyl acetate, in the presence of triethylamine. Also, a detailed spectral analysis of a new coumarin derivative is presented. Resonance assignment was achieved using one( 1H NMR and 13C NMR) and two-dimensional NMR techniques (1H1H-COSY, NOESY, HSQC, and HMBC). The NOESY correlations of protons from arylamino substituent and coumarin core indicate their spatial orientation.

scholarly journals SYNTHESIS AND COMPLETE NMR SPECTRAL ASSIGNMENTS OF NEW BENZYLAMINO COUMARIN DERIVATIVE

2020 ◽  
Vol 10 (2) ◽  
Author(s):  
Vidoslav Dekić ◽  
Niko Radulović ◽  
Milenko Ristić ◽  
Biljana Dekić ◽  
Novica Ristić
Keyword(s):  
Spectral Analysis ◽  
Ethyl Acetate ◽  
1H Nmr ◽  
Resonance Assignment ◽  
13C Nmr ◽  
Spatial Orientation ◽  
Good Yield ◽  
Coumarin Derivative ◽  
Two Dimensional ◽  
Nmr Techniques

This research involves the reaction of 4-chloro-3-nitrocoumarin and (4-methoxyphenyl)methanamine, whereby a novel coumarin derivative 4-[(4-methoxybenzyl) amino]-3-nitro-2H-chromen-2-one was obtained in good yield. The reaction was carried out in ethyl acetate, in the presence of triethylamine. Also, a detailed spectral analysis of a new coumarin derivative is presented. Resonance assignment was achieved using one- (1H NMR and 13C NMR) and two-dimensional NMR techniques (1H-1H-COSY, NOESY, HSQC, and HMBC). The NOESY correlations of protons from arylamino substituent and coumarin core indicate their spatial orientation.

scholarly journals How to Read and Interpret 1H-NMR and 13C-NMR Spectrums

2021 ◽  
Vol 6 (2) ◽  
pp. 267-298
Author(s):  
Ramdhan Gunawan ◽  
Asep Bayu Dani Nandiyanto
Keyword(s):  
Nuclear Magnetic Resonance ◽  
1H Nmr ◽  
13C Nmr ◽  
Chemical Compound ◽  
Nmr Spectra ◽  
Spectroscopic Technique ◽  
Complex Compounds ◽  
Resonance Spectroscopy ◽  
13C Nmr Spectra ◽  
Nmr Techniques

Nuclear magnetic resonance spectroscopy or NMR is a chemical instrument that can be used to evaluate the structure of a chemical compound other than FTIR, GC-MS, and HPLC. NMR spectroscopy commonly used for compound analysis is 1H-NMR and 13C-NMR. Techniques can be used to determine the structure conformation, the number of protons, and the number of carbons in the structure of a chemical compound. So far, there have been many publications related to the use of this spectroscopic technique. However, the steps in reading and interpreting the spectra of both 1H-NMR and 13C-NMR are not described in detail. Thus, in this paper, we described the steps in reading and interpreting the 1H-NMR and 13C-NMR spectra based on the level of difficulties: (1) simple compounds, (2) fairly complex compounds, (3) more complex compounds, and (4) very complex compounds.

Synthesis and Biological Evaluation of Various New Substituted 1,3,4-oxadiazole-2-thiols

2008 ◽  
Vol 59 (4) ◽  
Author(s):  
Gabriela Laura Almajan ◽  
Stefania Felicia Barbuceanu ◽  
Ioana Saramet ◽  
Mihaela Dinu ◽  
Cristian Vasile Doicin ◽  
...  
Keyword(s):  
Biological Activity ◽  
Plant Growth ◽  
1H Nmr ◽  
Elemental Analysis ◽  
13C Nmr ◽  
Biological Evaluation ◽  
Ethyl Chloroacetate ◽  
Low Concentrations ◽  
Synthesis And Biological Evaluation

5-[4-(4X-phenylsulfonyl)phenyl]-1,3,4-oxadiazole-2-thiols, X=H, Cl, Br, reacted with ethyl chloroacetate to give S-alkylated compounds. Aminomethylation of the thione form of oxadiazoles yielded N(3)-derivatives. All the products have been characterized by elemental analysis, IR, 1H-NMR and 13C-NMR. The plant-growth regulating effects of the title compounds were examined. From the biological activity results, we found that most compounds showed weak stimulatory activities at low concentrations.

Synthesis and Spectral Characterization of New S-Alkylated 1,2,4-Triazoles as Potential Biological Agents

2017 ◽  
Vol 68 (10) ◽  
pp. 2436-2439
Author(s):  
Stefania Felicia Barbuceanu ◽  
Laura Ileana Socea ◽  
Constantin Draghici ◽  
Elena Mihaela Pahontu ◽  
Theodora Venera Apostol ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Spectral Data ◽  
1H Nmr ◽  
Elemental Analysis ◽  
13C Nmr ◽  
Ethyl Bromide ◽  
Spectral Characterization ◽  
Basic Medium ◽  
Phenacyl Bromide

In the work we presented the behavior of 5-(4-(4-X-phenylsulfonyl)phenyl)-4-(n-propyl)-2H-1,2,4-triazole-3(4H)-thiones (X= Cl or Br) with some alkylation agents. Thus, new S-alkylated 1,2,4-triazole derivatives were synthesized by reaction of the corresponding 1,2,4-triazole-3-thione derivatives with different �-halogenated compounds (ethyl bromide, ethyl chloroacetate or phenacyl bromide), in basic medium. The structures of synthesized compounds were elucidated by spectral data (1H-NMR, 13C-NMR, mass spectrometry) and elemental analysis.

Benzimidazole Derivatives as Potential Antimicrobial and Antiulcer Agents: A Mini Review

2019 ◽  
Vol 19 (16) ◽  
pp. 1292-1297 ◽  
Author(s):  
Ali Mohd Ganie ◽  
Ayaz Mahmood Dar ◽  
Fairooz Ahmad Khan ◽  
Bashir Ahmad Dar
Keyword(s):  
Cell Lines ◽  
Cancer Cell ◽  
1H Nmr ◽  
13C Nmr ◽  
Benzimidazole Derivatives ◽  
Spectroscopic Techniques ◽  
One Pot ◽  
Biological Screening ◽  
Elemental Analyses ◽  
Characterization Studies

:Here in we report the number of strategies for the synthesis of differently substituted benzimidazole derivatives. The protocols involved in the syntheses of these derivatives were one-pot or multi-component. The characterization studies of these derivatives were carried by using different spectroscopic techniques (1H NMR, 13C NMR and MS) and elemental analyses. The biological screening studies revealed that these benzimidazole derivatives show potential antibacterial as well as antifungal behavior. These benzimidazole derivatives not only depicted potential antiulcer properties but also showed moderate to good anticancer/cytotoxic behavior against different cancer cell lines.

The Electron Effect of Aromatic Group: Control Conformation of 2-Aromatic Cyclododecanone Derivatives

2020 ◽  
Vol 24 (10) ◽  
pp. 1139-1147
Author(s):  
Yang Mingyan ◽  
Wang Daoquan ◽  
Wang Mingan
Keyword(s):  
1H Nmr ◽  
13C Nmr ◽  
Nmr Spectra ◽  
Coupling Constants ◽  
The Other ◽  
Repulsive Interaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Electron Effect ◽  
Group Control

2-Phenylcyclododecanone and 2-cyclohexylcyclododecanone derivatives were synthesized and characterized by 1H NMR, 13C NMR, HR-ESI-MS and X-ray diffraction. Their preferred conformations were analyzed by the coupling constants in the 1H NMR spectra and X-ray diffraction, which showed the skeleton ring of these derivatives containing [3333]-2-one conformation, and the phenyl groups were located at the side-exo position of [3333]-2-one conformation due to the strong π-π repulsive interaction between the π- electron of benzene ring and π-electron of carbonyl group. The cyclohexyl groups were located at the corner-syn or the side-exo position of [3333]-2-one conformation depending on the hindrance of the other substituted groups. The π-π electron effect played a crucial role in efficiently controlling the preferred conformation of 2-aromatic cyclododecanone and the other 2-aromatic macrocyclic derivatives with the similar preferred square and rectangular conformations.

Synthesis and Anticonvulsant Activity of 3-(alkylamino, alkoxy)-1,3,4,5- Tetrahydro-2H-benzo [b] azepine-2-one Derivatives

2018 ◽  
Vol 17 (6) ◽  
pp. 448-457 ◽  
Author(s):  
Xia Huang ◽  
Tie Chen ◽  
Rong-Bi Han ◽  
Feng-Yu Piao
Keyword(s):  
1H Nmr ◽  
Elemental Analysis ◽  
13C Nmr ◽  
Anticonvulsant Activity ◽  
Mass Spectra ◽  
Maximal Electroshock ◽  
Test Compound ◽  
Maximal Electroshock Test ◽  
Mes Test ◽  
Structure Activity

Background & Objective: A series of novel 3-Substituted-1,3,4,5-Tetrahydro-2H-benzo [b] azepine-2-one Derivatives (4, 5, 7, 10, 12, 5a-j, 8a-e) were synthesized from 1,2,3,4-Tetrahydro-1- naphthalenone. The structures of these compounds were confirmed by IR, 1H NMR, 13C NMR, MASS spectra and elemental analysis. Their anticonvulsant activity was evaluated by the maximal electroshock (MES) test, subcutaneous pentylenetetrazol (scPTZ) test, and their neurotoxicity was evaluated by the rotarod neurotoxicity test. Compound 4 showed the maximum anticonvulsant activity against the maximal electroshock test (ED50=26.4, PI =3.2) and against the subcutaneous pentylenetetrazol test (ED50=40.2, PI =2.1). Conclusion: Possible structure-activity relationship was discussed.

Sign in / Sign up

Export Citation Format

Share Document