Studies of Erythrina alkaloids: VII—13C NMR spectral studies of some Erythina alkaloids

Chawla, Amit Kumar; Chunchatprasert, S.; Jackson, Anthony H.

doi:10.1002/omr.1270210110

Cited by 35 publications

(36 citation statements)

References 7 publications

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“…Our data for erysotrine (1), erysodine (2), erythraline (3), erytharbine (4), and erysotrine N-oxide (5), backed up by two-dimensional experiments, lead to assignments that are in complete agreement with those published in the reviews of Chawla et al 1 and Amer et al, 2 and in most of the later papers, which follow a common pattern. The only assignments we have identified diverging from this scheme are in the previously cited article on E. fusca alkaloids by Calle et al, 25 where the 13 C NMR assignments of C-1 (135.5 ppm) and C-2 (123.2 ppm) of 8-oxoerysodine, using only one-dimensional spectra, are inverted, and in a paper by Flausino et al, 27 using 1 H-1 H COSY, HMQC and HMBC, who arrived at a similar conclusion for 11a-hydroxyerythravine (in pyridine-d 5 ) and 11a-hydroxyerysotrine (in CDCl 3 ): d 135.0 and 131.5 (C-1), 124.5 and 125.5 (C-2), plus 124.4 and 123.5 (C-7), respectively.…”

Section: Figure 2 (A) Hmbc Correlations and (B) Noesy Correlations Fsupporting

confidence: 87%

“…However, in the 1960's 1 H NMR began to be used routinely in the structure elucidation of natural products, and in 1983 a seminal paper was published in which the 13 C NMR spectra of 20 Erythrina alkaloids were described and interpreted. 1 A 1991 review collected the spectroscopic data of all the members of this family known at that date, 2 including the 1 H NMR assignments of 66 of them and the 13 C NMR assignments of 27 compounds (which include the 20 13 C NMR interpretations published in 1983). More recent work, based on 1 H-1 H COSY, NOESY and 1 H-13 C 2D spectra (e.g.…”

Section: Introductionmentioning

confidence: 99%

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STRUCTURAL REASSIGNMENT OF EPIERYTHRATIDINE, AN ALKALOID FROM Erythrinafusca, BASED ON NMR STUDIES AND COMPUTATIONAL METHODS

García‐Beltrán

Soto‐Delgado

Iturriaga-Vásquez

et al. 2012

J. Chil. Chem. Soc.

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The diene Erythrina alkaloids erysotrine (1), erysodine (2), erythraline (3), erytharbine (4), and erysotrine N-oxide (5), plus the hydroxylated dihydro derivative of 1, epierythratidine (6) were isolated from seeds of Erythrina fusca Lour., and their 1 H and 13 C NMR spectra were completely assigned using 2D experiments (H-H COSY, HMQC, HMBC and H-H NOESY). Our assignments for 1-5 agree well with the literature, but the present work shows that the published interpretation of the spectra of 6 must be revised. A combined study based on NMR data and quantum-mechanical calculations using DFT/GIAO indicate that 6 is the correct structure of epierythratidine.

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Section: Figure 2 (A) Hmbc Correlations and (B) Noesy Correlations Fsupporting

confidence: 87%

Section: Introductionmentioning

confidence: 99%

STRUCTURAL REASSIGNMENT OF EPIERYTHRATIDINE, AN ALKALOID FROM Erythrinafusca, BASED ON NMR STUDIES AND COMPUTATIONAL METHODS

García‐Beltrán

Soto‐Delgado

Iturriaga-Vásquez

et al. 2012

J. Chil. Chem. Soc.

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“…13) These facts indicated that a sodium sulfate group was located at C-15. The nuclear Overhauser effect spectroscopy (NOESY) correlations ( Fig.…”

Section: Resultsmentioning

confidence: 98%

Erythrinan Alkaloids from Seeds of Erythrina velutina

Ozawa

Kishida

Ohsaki

2011

CHEMICAL & PHARMACEUTICAL BULLETIN

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In the course of our search for biologically and structurally unique compounds from medicinal plants in tropical and subtropical regions, 1) we have continued to investigate the constituents of Erythrina species. The genus Erythrina (Leguminosae) consists of more than a hundred species of trees, shrubs and herbaceous plants that are widely distributed throughout tropical and warm regions of the world. 2)Erythrina velutina WILLD. is commonly called Mulungu in Brazil, and its bark is used as a remedy for insomnia, convulsion, nervous cough and rheumatism in the north of Brazil. 3)Phytochemical analyses have demonstrated that Erythrina plants accumulate Erythrinan alkaloids,4,5) benzylisoquinoline alkaloids, 6) isoflavonoids 7) and pretocarpanes.8) The Erythrinan alkaloids are characterized by their unique tetracyclic spiro-amine framework. Therefore, their structures with various biological properties have recently attracted attention as a synthetic target. 9,10) In previous papers, we described the isolation and structural characterization of an indole derivative, hypaphorine, and its sleep-inducing effect on normal mice, 11) as well as the isolation and structural characterization of a new Erythrinan alkaloid, erysodine N-oxide, together with known compounds, and the evaluation of the isolated compounds in terms of the enhanced activity for tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL). 12) In this paper, we describe the isolation and structural elucidation of four new Erythrinan alkaloids (1-4), including novel sulfated alkaloids from the high polarity portion extracted with n-BuOH, of the seeds of Erythrina velutina. The new constituents isolated from E. velutina were elucidated by spectroscopic methods, including 1 H-and 13 C-NMR, high resolution (HR)-MS and comparison with data in the literature. Results and DiscussionThe seeds of E. velutina were crushed and then extracted with MeOH and 80% MeOH. These MeOH-soluble materials were successively partitioned between petroleum ether, EtOAc and 3% tartaric acid. Each water-soluble material was adjusted to pH 10 with Na 2 CO 3 and then partitioned between CHCl 3 and n-BuOH to obtain alkaloidal portions. The nBuOH-soluble materials were subjected to amino-silica-gel and silica-gel column chromatography. The obtained fractions were further purified using a silica-gel column and silica-gel HPLC to afford four new compounds 1-4 and a known compound, hypaphorine.Compound , suggesting the presence of a sulfate group. The UV spectrum showed l max (MeOH) at 226 (log e 4.20) and 277 (log e 3.39) nm. The gross structure of 1 was deduced from detailed analysis of the 1 H-and 13 C-NMR-aided 2D-NMR experiments ( 1 H-1 H correlation spectroscopy (COSY), heteronuclear single quantum coherence (HSQC) and heteronuclear multiple bond connectivity (HMBC)), which indicated the presence of four methylenes, one sp 3 quaternary carbon, one sp 3 oxy-methine, three sp 2 methines, one sp 2 quaternary carbon, two aromatic methine carbons, two aromatic quaternary carb...

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“…Phytochemical study of alkaloidal CHCl 3 and n-BuOH extracts of Erythrina crista-galli led to the isolation of two new alkaloids, cristanines A (1) and B (2), together with ten known Erythrinan alkaloids, including erythratine (3), 17) crystamidine (4), 3,11) erysovine (5), erythraline (7), 8-oxoerythraline (8), 18) erythrinine (9), 8-oxo-erythrinine (10), 19) erythratidine (11) and epi-erythratidine (12) 18) as well as one indole alkaloid, hypaphorine (13).…”

Section: Resultsmentioning

confidence: 99%

Structures of New Erythrinan Alkaloids and Nitric Oxide Production Inhibitors from Erythrina crista-galli

Ozawa

Kawamata

Etoh

et al. 2010

CHEMICAL & PHARMACEUTICAL BULLETIN

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Two new Erythrinan alkaloids, cristanines A and B (1, 2), were isolated from the bark of Erythrina cristagalli L. together with nine known Erythrinan alkaloids (3-5, 7-12) and an indole alkaloid (13). The structures of the compounds, cristanines A (1) and B (2), were elucidated by spectroscopic methods. Three of the twelve compounds isolated showed significant inhibitory activity on lipopolysaccharide induced nitric oxide (NO) production.

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Studies of Erythrina alkaloids: VII—¹³C NMR spectral studies of some Erythina alkaloids

Cited by 35 publications

References 7 publications

STRUCTURAL REASSIGNMENT OF EPIERYTHRATIDINE, AN ALKALOID FROM Erythrinafusca, BASED ON NMR STUDIES AND COMPUTATIONAL METHODS

STRUCTURAL REASSIGNMENT OF EPIERYTHRATIDINE, AN ALKALOID FROM Erythrinafusca, BASED ON NMR STUDIES AND COMPUTATIONAL METHODS

Erythrinan Alkaloids from Seeds of Erythrina velutina

Structures of New Erythrinan Alkaloids and Nitric Oxide Production Inhibitors from Erythrina crista-galli

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