scholarly journals Assignment of the 1H and 13C spectra of aspidocarpine and assignment of the structure and stereochemistry of the von Braun reaction product of aspidocarpine by 2D nmr spectroscopy

1987 ◽  
Vol 65 (1) ◽  
pp. 200-204 ◽  
Author(s):  
Stewart McLean ◽  
William F. Reynolds ◽  
Xingpei Zhu
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Cyanogen Bromide ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
2D Nmr Spectra

The 13C and 1H spectra of aspidocarpine and the spectra, structure, and stereochemistry of the product of its von Braun reaction with cyanogen bromide have been totally assigned by a combination of homonuclear (COSY-45) and direct and indirect heteronuclear shift-correlated 2D nmr spectra.

scholarly journals Phenylpropanoids and Polyacetylenes from Ligusticum mutellina (Apiaceae) of Tyrolean Origin

2002 ◽  
Vol 70 (1) ◽  
pp. 101-109 ◽  
Author(s):  
Spitaler Renate ◽  
Ellmerer-Müller Ernst-Peter ◽  
Zidorn Christian ◽  
Stuppner Hermann
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Close Inspection ◽  
1H And 13C Nmr ◽  
Nmr Data ◽  
First Time

Roots of Ligusticum mutellina (L.) CRANTZ afforded five major compounds, the phenylpropanoids trans-isoelemicin (1), sarisan (2), and trans-isomyristicin (3), and the polyacetylenes falcarindiol (4) and falcarindiol-3-O-acetate (5). Structures were assigned by 1D- and 2D-NMR spectroscopy. Close inspection of the NMR spectra of falcarindiol-3-O-acetate (5) and comparison with the literature revealed that published NMR data for this compound are most probably attributable to cis or trans Δ2-isofalcarindiol-1-O-acetate (6a/6b). 1H and 13C NMR data for falcarindiol-3-O-acetate are given and trans-isoelemicin (1), sarisan (2), and trans-isomyristicin (3), falcarindiol (4), and falcarindiol-3-O-acetate (5) are reported for the first time from Ligusticum mutellina. Chemosystematic and ethnopharmacological implications of the findings are discussed briefly.

scholarly journals Assessment of Astaxanthin Accumulation in Hepatocytes of Atlantic Salmon Fed Different Diets Using NMR Spectroscopy

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1769
Author(s):  
Elena Shumilina ◽  
Alessandra Ciampa ◽  
Trine Ytrestøyl ◽  
Alexander Dikiy
Keyword(s):  
Nmr Spectroscopy ◽  
Atlantic Salmon ◽  
Nmr Spectra ◽  
2D Nmr ◽  
Fish Feed ◽  
Marine Phospholipids ◽  
2D Nmr Spectra ◽  
Farmed Atlantic Salmon ◽  
Short Time ◽  
Detection And Quantification

This study aimed to assess the astaxanthin (Ax) accumulation in hepatocytes isolated from farmed Atlantic salmon fed different diets (rich marine, poor, poor with marine phospholipids (MPL) and poor with docosahexaenoic acid (DHA)). Nuclear magnetic resonance (NMR) spectroscopy was used for the Ax detection and quantification. The use of the 13C-enriched Ax allowed the assessment of short-time Ax metabolism. The substitution of fish oil and meal in fish feed on plant analogs and the addition of MPL caused further catabolism and decrease of Ax accumulation in hepatocytes from 17 to about 6 mg/kg or to almost zero in the case of DHA addition. Signals assignment of the native and 13C-enriched astaxanthin in acetone were performed using 1D and 2D NMR spectra.

scholarly journals Ultrafast 2D 1H-1H NMR spectroscopy of DNP-hyperpolarised substrates for the analysis of mixtures

2021 ◽  
Author(s):  
Kawarpal Singh ◽  
Corentin Jacquemmoz ◽  
Patrick Giraudeau ◽  
Lucio Frydman ◽  
Jean-Nicolas Dumez
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
1H Nmr Spectroscopy ◽  
Nmr Spectra ◽  
2D Nmr ◽  
Multiple Quantum ◽  
Dynamic Nuclear Polarisation ◽  
Nuclear Polarisation ◽  
2D Nmr Spectra

We show that TOCSY and multiple-quantum (MQ) 2D NMR spectra can be obtained for mixtures of substrates hyperpolarised by dissolution dynamic nuclear polarisation (D-DNP). This is achieved by combining optimised...

scholarly journals Challenges in the decomposition of 2D NMR spectra of mixtures of small molecules

2019 ◽  
Vol 218 ◽  
pp. 459-480 ◽  
Author(s):  
Afef Cherni ◽  
Elena Piersanti ◽  
Sandrine Anthoine ◽  
Caroline Chaux ◽  
Laetitia Shintu ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Small Molecules ◽  
Blind Source Separation ◽  
Nmr Spectra ◽  
Source Separation ◽  
2D Nmr ◽  
Blind Identification ◽  
2D Nmr Spectra

In this paper we present a general approach for the blind identification of compounds from solutions using NMR spectroscopy and blind source separation algorithms.

Complete assignments in 1H and 13C NMR Spectra of uraphine and 6-oxocorumdephine using 2D NMR spectroscopy

2012 ◽  
Vol 48 (4) ◽  
pp. 717-718
Author(s):  
T. M. Gabbasov ◽  
E. M. Tsyrlina ◽  
L. V. Spirikhin ◽  
M. S. Yunusov
Keyword(s):  
Nmr Spectroscopy ◽  
13C Nmr ◽  
Nmr Spectra ◽  
2D Nmr ◽  
13C Nmr Spectra ◽  
2D Nmr Spectroscopy ◽  
1H And 13C Nmr

scholarly journals Morin as a Preservative for Delaying Senescence of Banana

Biomolecules ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 52 ◽  
Author(s):  
Hong Zhu ◽  
Jiali Yang ◽  
Yueming Jiang ◽  
Jun Zeng ◽  
Xuesong Zhou ◽  
...  
Keyword(s):  
Amino Acids ◽  
Principal Component Analysis ◽  
Nuclear Magnetic Resonance ◽  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Nutritional Value ◽  
Principal Component ◽  
2D Nmr ◽  
Climacteric Fruit ◽  
2D Nmr Spectra

Banana is a climacteric fruit with desirable palatability and high nutritional value. It ripens rapidly accompanied with metabolite changes during postharvest storage. In this work, morin was applied to treat banana to delay senescence. Nuclear magnetic resonance (NMR) spectroscopy was used to monitor the changes of metabolite composition and levels in banana. The results showed that morin significantly delayed the changes of color and firmness. 1D and 2D NMR spectra reflected that the levels and composition of metabolites were changed with the senescence initiation. The principal component analysis revealed that the first principal components responsible for banana senescence were carbohydrates, amino acids, lipids and phenolics. Morin treatment delayed the transformation of starch to glucose, fructose and sucrose, accelerated the accumulations of alanine and γ-Amino-butyrate (GABA), postponed the generations of valine and l-aspartic acid, suppressed the degradation of saponin a. It indicated that morin was effective in delaying banana senescence.

Triazene derivatives of (1,x)-diazacycloalkanes. Part VIII. Synthesis and characterization of a series of 1,4-di[2-aryl-1-diazenyl]-2-methylpiperazines1

2007 ◽  
Vol 85 (3) ◽  
pp. 189-196 ◽  
Author(s):  
Naomi Hunter ◽  
Reid Tingley ◽  
Brad Peori ◽  
Keith Vaughan
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
Diazonium Salt ◽  
Mass Measurement ◽  
Aromatic Proton ◽  
2D Nmr ◽  
2D Nmr Spectroscopy ◽  
Piperazine Ring ◽  
Methylene Groups ◽  
Type 3

A series of 1,4-di-[2-aryl-1-diazenyl]-2-methylpiperazines (4a–n) have been synthesized by the reaction of 2-methylpiperazine with 2 equiv. of the appropriate diazonium salt. The products have been characterized by IR and NMR spectroscopy, and the molecular composition has been verified by HR-EIMS, with accurate mass measurement of the molecular ion. The presence of a chiral centre at C2 of the piperazine ring in the bistriazene 4 creates a multitude of diastereotopic protons in the methylene groups of the piperazine ring, as evidenced by the complexity of the NMR spectra, which nevertheless can be fully assigned in some cases, such as the tolyl- (4h) and phenyl- (4j) derivatives. These two compounds also show a discrimination between the two N-arydiazenyl groups, as evidenced by the doubling of several aromatic-carbon signals in the 13C NMR spectra. The assignment of the proton and carbon signals in 4h and 4j has been aided by the use of 2D NMR spectroscopy. A DEPT spectrum of 4j clearly discriminates the methylene carbons and also indicates the methine carbons of the piperazine ring. COSY spectra provide clear information about the interactions between diastereotopic protons; when these results are combined with the results of HSQC spectroscopy, the proton and carbon signals can be fully correlated, leading to an unequivocal assignment of the proton and carbon atoms of the piperazine ring. The HSQC spectrum of 4j also gives a complete correlation of the aromatic-proton and -carbon signals. These results compare favorably with the previously reported assignments of proton and carbon signals for triazenes of type 1 and bistriazenes of type 3.Key words: triazene, bistriazene, piperazine, 2-methylpiperazine, diastereotopic protons, diazonium coupling, 2D NMR, COSY, DEPT, HSQC.

scholarly journals 1D and 2D NMR spectroscopy for identification of carbamide-containing biologically active compounds

2021 ◽  
Vol 101 (1) ◽  
pp. 71-81
Author(s):  
A.A. Bakibaev ◽  
◽  
S.Yu. Panshina ◽  
O.V. Ponomarenko ◽  
V.S. Malkov ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Nmr Spectra ◽  
System Analysis ◽  
Chemical Shifts ◽  
2D Nmr ◽  
Biologically Active Compounds ◽  
Biologically Active ◽  
2D Nmr Spectroscopy ◽  
Active Compounds ◽  
Bicyclic Structure

Urea (carbamide) is the main end product of amino acids' metabolism in mammals. Extensive research in the field of urea chemistryhas contributed to the creation of many biologically active and other compounds based on the carbamide fragment NH–CO–NH. The substituting groups of urea directly affect its properties and characteristics which are reflected in the NMR spectral data and this circumstance can be the basis for the identification of urea derivatives. In this work, chemical shifts in the NMR spectra of urea and its acyclic structure, barbituric series, imidazolidinone series and bicyclic structure derivativeswere studied and identi-fied. A system analysis was carried out to determine the effect of the type of substituents on the positions of signals of the NH-CO-NH fragment in the NMR spectra. The possibility of 2D NMR spectroscopy using to simplify the identification procedurefor complex mixtureswas shown in the paper. The combined use of 1D and 2D NMR spectroscopy is convenient and informative to establishthe structure of biologically active compounds. These methods make it possible to determine the presence and type of impurities, as well as to establish thedestruction processes leading to the corresponding impurities.

Sign in / Sign up

Export Citation Format

Share Document