Journal ArticleDOI
13C-NMR. Analysis of the Roxburghines†
TLDR
The 13C shifts of the alkaloids roxburghine B, C, D and E were determined in this paper, and they confirmed the following configurations for the last three bases: C(18α)-normal, C( 18α)-pseudo, and C((18β)-epi-allo) respectively.Abstract:
The 13C shifts of the alkaloids roxburghine B, C, D and E are determined. They confirm the following configurations for the last three bases: C(18α)-normal, C(18α)-pseudo and C(18β)-pseudo, respectively. Roxburghine B is shown to be a C(18β)-epi-allo isomer.read more
Citations
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Journal ArticleDOI
13C NMR spectroscopy of indole derivatives
TL;DR: The chemical shifts of 298 naturally occurring and synthetic compounds containing the indole chromophoric group are listed in this paper, where substitutions on the heteroaromatic five-membered ring are discussed.
Book ChapterDOI
The Use of Carbon-13 Nuclear Magnetic Resonance Spectroscopy in Natural Products Chemistry
F. W. Wehrli,T. Nishida +1 more
TL;DR: In this article, the authors used broadband excitation and Fourier transform methods to record 13C n. m. r. spectra on sample quantities down to the submilligram level.
Journal ArticleDOI
Aromatic chemical shifts in ar-hydroxy- and -methoxy-substituted indole alkaloids; reference data and substituent-induced chemical shifts for ten different chromophoric groups
TL;DR: In this article, substituent-induced chemical shifts have been calculated for various types of ar-hydroxy- and -methoxy-substituted indole alkaloids.
Book ChapterDOI
Nuclear Magnetic Resonance of Alkaloids
TL;DR: In this paper, the authors describe characteristic features of the NMR spectra of alkaloids, illustrated by examples taken predominantly from papers published during the period January 1969-June 1972.
Journal ArticleDOI
13C NMR analysis of anthraquinones as models for anthracycline Antibiotics
TL;DR: In this article, the effect of substituents OH, OMe, OAc, and COMe on the chemical shifts has been studied for monosubstituted and some 1,5-and 1,8-disubstitized 9,10-AQ compounds.
References
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Journal ArticleDOI
Carbon-13 magnetic resonance. XXIII. Methyldecalins
Journal ArticleDOI
The structure of roxburghines A-E, new indole alkaloids from an Uncaria Sp.
TL;DR: The structural elucidation of roxburghines A–E, new diastereoisomeric indole alkaloids C 31 H 32 N 4 O 2, isolated from the leaves and stems of an Uncaria Sp.
Journal ArticleDOI
Mass spectrometry in the analysis of steroid drugs and their metabolites: electron-impact-induced fragmentation of ring D.
TL;DR: Certain steroid drugs, their metabolites, and related model compounds which possess a 17‐hydroxy group can be converted to trimethylsilyl ethers which give characteristic ions of type [128 + R]+in their mass spectra, where R is the mass of the other 17‐substituent.
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