scholarly journals 1H AND 13C NMR SPECTRA OF STRYCHNOS ALKALOIDS: SELECTED NMR UPDATES

2020 ◽  
Vol 1 (14) ◽  
pp. 77-94
Author(s):  
Valentin Semenov ◽  
Dmitriy Samul'cev ◽  
Leonid Krivdin
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Mean Absolute Error ◽  
Chemical Shifts ◽  
Absolute Error ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
13C Nmr Chemical Shifts ◽  
Nmr Data ◽  
Distinguished Group

The PBE0/pcSseg-2//pcseg-2 calculations of 1H and 13C NMR chemical shifts were performed for a classical series of 12 Strychnos alkaloids (except for the earlier studied parent strychnine), namely akuammicine, isostrychnine, rosibiline, tsilanine, spermostrychnine, diaboline, cyclostrychnine, henningsamide, strychnosilidine, strychnobrasiline, holstiine, and icajine. It was found that calculated 1H and 13C NMR chemical shifts demonstrated markedly good correlations with available experimental data characterized by a mean absolute error of 0.22 ppm for the range of 8 ppm for protons and 1.97 ppm for the range of 180 ppm for carbons. Complimentary, present results provide essential NMR update and fill a gap in the NMR data of this distinguished group of the vitally important natural products.

Determination of second-order association constants by global analysis of 1H and 13C NMR chemical shifts.

Steroids ◽  
2003 ◽  
Vol 68 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Wajih Al-Soufi ◽  
Pedro Ramos Cabrer ◽  
Aida Jover ◽  
Rosane M. Budal ◽  
José Vázquez Tato
Keyword(s):  
13C Nmr ◽  
Chemical Shifts ◽  
Global Analysis ◽  
Association Constants ◽  
Second Order ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
13C Nmr Chemical Shifts

Assignment of 1H and 13C NMR chemical shifts of a d-mannan composed of α-(1 → 2) and α-(1 → 6) linkages obtained from Candida kefyr IFO 0586 strain

1995 ◽  
Vol 267 (2) ◽  
pp. 299-306 ◽  
Author(s):  
Hidemitsu Kobayashi ◽  
Masahiko Watanabe ◽  
Mariko Komido ◽  
Kyoko Matsuda ◽  
Tomoko Ikeda-Hasebe ◽  
...  
Keyword(s):  
13C Nmr ◽  
Chemical Shifts ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
13C Nmr Chemical Shifts ◽  
Candida Kefyr

The determination of the stereochemistry of epoxides located at the 5,6-positions of decalinic systems: An empirical method based on 13C NMR chemical shifts

2002 ◽  
Vol 80 (7) ◽  
pp. 774-778 ◽  
Author(s):  
Raquel M Cravero ◽  
Guillermo R Labadie ◽  
Manuel González Sierra
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Empirical Method ◽  
Nmr Chemical Shifts ◽  
13C Nmr Chemical Shifts ◽  
Empirical Rule ◽  
C Nmr

The 13C NMR spectra of a series of 5,6-epoxides in decalinic systems were studied. The interpretation of the chemical shifts allowed us to formulate an empirical rule to predict the epoxide stereochemistry. A discussion of the scope and limitations of this method and its extension to larger carbon skeletons is also presented.Key words: epoxide stereochemistry, 13C NMR, NMR, decalinic systems, oxiranes.

scholarly journals 1H and 13C NMR spectral assignments of an amino acid-coumarin hybrid

2013 ◽  
Vol 11 (1) ◽  
pp. 101-107
Author(s):  
Vidoslav Dekic ◽  
Biljana Dekic ◽  
Niko Radulovic
Keyword(s):  
Spectral Analysis ◽  
Amino Acid ◽  
13C Nmr ◽  
Chemical Shifts ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
13C Nmr Chemical Shifts ◽  
Complete Assignment ◽  
Acid Derivate ◽  
Coumarin Amino Acid

Synthesis and detailed spectral analysis of a new 4-substituted coumarin-amino acid derivate are presented in this paper. A new glycine derivate of (3-nitro-2-oxo-2H-chromen-4-yl)amino]acetate was prepared by condensation of 4-chloro-3-nitrocoumarin and ethyl glycinate hydrochloride. The complete assignment of 1H and 13C NMR chemical shifts of the synthesized compound was carried out by the aid of a combination of 1D (1H and 13C NMR) and 2D (1H-1H-COSY, NOESY, HSQC and HMBC) NMR experiments.

Interpretation of 13C NMR chemical shifts of Hantzsch's pyridines and 1,4-dihydropyridines

1984 ◽  
Vol 49 (10) ◽  
pp. 2393-2399 ◽  
Author(s):  
Antonín Kurfürst ◽  
Petr Trška ◽  
Igor Goljer
Keyword(s):  
13C Nmr ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
Correlation Equations ◽  
Pyridine Derivatives ◽  
Nmr Chemical Shifts ◽  
13C Nmr Chemical Shifts ◽  
C Nmr

1H and 13C NMR spectra of twelve 1,4-dihydropyridines I and twelve corresponding pyridine derivatives II have been measured in hexadeuteriodimethyl sulphoxide and interpreted. Correlation equations are given for the chemical shifts of the atoms in the heterocyclic rings of the two series of compounds.

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