13C NMR des alcaloïdes des Strychnos: Les dérivés de l'harmane et de l'usambarensine

Coune, Claude; Angenot, Luc; Denoel, J.

doi:10.1016/0031-9422(80)83024-x

Cited by 33 publications

(13 citation statements)

References 11 publications

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“…The structures of harmol ( 3 ), THH ( 5 ), harmaline ( 6 ) (Coune et al, 1980; Atta-ur-Rehman and Tayyaba, 1972), harmine ( 7 ), (−)-2 R ,3 R –epicatechin ( 8 ) (Balde et al, 1991; Sun et al, 2006) and (−)-2 R ,3 R –epicatechin-4β8-(−)-2 R ,3 R –epicatechin (procyanidin B2) ( 9 ) (Barrett et al, 1979; Korver and Wilkins, 1971; Khan et al, 1997) were determined by physical and spectroscopic data ( 1 H and 13 C NMR, 2D NMR experiments, and MS) as well as by direct comparison, except for 9 , with their respective authentic samples. The 1 H and 13 C NMR spectra of harmaline ( 6 ) in CD 3 OD exhibited an equilibrium between imine-enamine tautomeric forms (Coune et al, 1980; Atta-ur-Rehman and Tayyaba, 1972).…”

Section: Resultsmentioning

confidence: 99%

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Banisteriopsis caapi, a unique combination of MAO inhibitory and antioxidative constituents for the activities relevant to neurodegenerative disorders and Parkinson's disease

Samoylenko

Rahman

Tekwani

et al. 2010

Journal of Ethnopharmacology

122

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Aim of the study-Parkinson's disease is a neurological disorder mostly effecting the elder population of the world. Currently there is no definitive treatment or cure for this disease. Therefore, in this study the composition and constituents of the aqueous extract of B. caapi for monoamine oxidases (MAO) inhibitory and antioxidant activities were assessed, which are relevant to the prevention of neurological disorders, including Parkinsonism.Materials and methods-The aqueous extract of B. caapi stems was standardized and then fractionated using reversed-phase (RP) chromatography. Pure compounds were isolated either by reversed-phase (RP) chromatography or centrifugal preparative TLC, using a Chromatotron ® . Structure elucidation was carried out by 1D and 2D NMR, Mass, IR and Circular Dichroism spectroscopy and chemical derivatization. Chemical profiling of the extract was carried out with RP-HPLC. The inhibitory activity of MAO-A, MAO-B, acetylcholinesterase, butyrylcholinesterase and catechol-O-methyl transferase enzymes, as well as antioxidant and cytotoxic activities of both B. caapi extract and isolated compounds were evaluated.Results-An examination of the aqueous extracts of B. caapi cultivar Da Vine yielded two new alkaloidal glycosides, named banistenoside A (1) and banistenoside B (2), containing "azepino[1,2-a]tetrahydro-β-carboline" unique carbon framework. One additional new natural tetrahydronorharmine (4), four known β-carbolines harmol (3), tetrahydroharmine (5), harmaline (6) and harmine (7), two known proanthocyanidines (−)-epicatechin (8) This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 10-13, 17, 18) were also prepared. Harmaline (6) and harmine (7) showed potent in vitro inhibitory activity against recombinant human brain monoamine oxidase (MAO) -A and -B enzymes (IC 50 2.5 and 2.0 nM, and 25 and 20 µM, respectively), and (−)-epicatechin (8) and (−)-procyanidin B2 (9) showed potent antioxidant and moderate MAO-B inhibitory activities (IC 50 <0.13 and 0.57 µg/mL, and 65 and 35 µM). HPLC analysis revealed that most of the dominant chemical and bioactive markers (1, 2, 5, 7-9) were present in high concentrations in dried bark of large branch. Analysis of regular/commercial B. caapi dried stems showed a similar qualitative HPLC pattern, but relatively low content of dominant markers 1, 2, 7, and 9, which led to decreased MAO inhibitory and antioxidant potency. NIH Public AccessAuthor Manuscript J Ethnopharmacol. Author manuscript; available in PMC 2011 February 3.Conclusion-Collectively, these results give additional basis to the existing claim of B. caapi stem extract...

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Section: Resultsmentioning

confidence: 99%

“…The 1 H and 13 C NMR spectra of harmaline ( 6 ) in CD 3 OD exhibited an equilibrium between imine-enamine tautomeric forms (Coune et al, 1980; Atta-ur-Rehman and Tayyaba, 1972). The imine was predominant in DMSO-d 6 (aprotic solvent), while both the tautomers were detected in CD 3 OD/ trifluroacetic acid (1 drop) as mixtures in the NMR spectra.…”

Section: Resultsmentioning

confidence: 99%

Banisteriopsis caapi, a unique combination of MAO inhibitory and antioxidative constituents for the activities relevant to neurodegenerative disorders and Parkinson's disease

Samoylenko

Rahman

Tekwani

et al. 2010

Journal of Ethnopharmacology

122

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“…The derivatives have been characterized by spectral studies, including IR, UV, EIMS, HREIMS, 1D ( 1 H-NMR and 13 C-NMR; Broad Band decoupled, DEPT), and 2D-NMR (COSY-45, TOCSY, HMQC and HMBC) (See Experimental, Table 2 and Table 3 ) and comparison of the spectral data with reported values of similar compounds [ 13 , 18 , 19 ]. For the 10-acyl analogues (see compound 3 in Table 2 ), the characteristic H-9 and H-12 peaks appeared in the 1 H-NMR spectra as one-proton singlets at ~ δ 8.5 and 7.1, respectively, confirming the substitution at C-10.…”

Section: Resultsmentioning

confidence: 99%

A Simple, Rapid and Mild One Pot Synthesis of Benzene Ring Acylated and Demethylated Analogues of Harmine under Solvent-free Conditions

et al. 2008

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A simple, rapid, solvent-free, room temperature one pot synthesis of benzene ring acylated and demethylated analogues of harmine using acyl halides/acid anhydrides and AlCl3 has been developed. Eight different acyl halides/acid anhydrides were used in the synthesis. The resulting mixture of products was separated by column chromatography to afford 10- and 12-monoacyl analogues, along with 10,12-diacyl-11-hydroxy products. In five cases the corresponding 10-acyl-11-hydroxy analogues were also obtained. Yields from the eight syntheses (29 products in total) were in the 6-34% range and all compounds were fully characterized.

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“…In sulfuric acid solutions, benzene was used as an external standard (coaxial tube). The assignments were made with the aid of the Frequency Offresonance Decoupling Spectra (SFORD) and the I3C nmr data of the alkaloids were taken from the literature (15)(16)(17)(18). Also, to confirm the structural assignments of the sulfonated products the spectra of three model compounds 1, 8, and 9 were recorded in sulfuric acid solutions and DMSO.…”

Section: Methodsmentioning

confidence: 99%

“…The assignments of the 13C resonances of the alkaloids in DMSO were aided by the literature data (15)(16)(17)(18). As there are no data on the 13C chemical shifts of these alkaloids in concentrated sulfuric acid solutions, the following procedure was used to assign the 13C signals in these media; as is known (19,20), the (3-carboline alkaloids are very easily protonated on their pyridinic nitrogen atom (pK, values ranged between 7 and 10).…”

Section: Methodsmentioning

confidence: 99%

Sulfonation reactions of (β-carbolines

Guzman¹,

Almeida²,

Toledo³

et al. 1989

Can. J. Chem.

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Can. J. Chem. 67,720 (1989).The homogeneous sulfonations of P-carboline derivatives norharmane 2, harmane 3, harmine 4, harm01 5, N,N1-dimethylharmane 6, arid harmaline 7 have been studied in 80-90% w/w sulfuric acid solutions at 25OC. Ultraviolet-visible and I3C nuclear magnetic resonance spectra and chemical analysis of the reaction mixtures show that for all the substrates studied only C-6 sulfonated products are obtained. The sulfonation reactions of the benzene unsubstituted substrates 2 , 3 , and 6 and the partially aromatic substrate 7 proceed by direct electrophilic attack of the H3SO4+ cation on the benzene ring of the P-carboline skeleton. Sulfonation of 4 and 5 at the lower sulfuric acid concentrations is effected by the H3S04+ entity. With increasing sulfuric acid concentration there is a gradual changeover of the sulfonating entity from H3S04+ to H2S207. The different mechanisms of sulfonation are discussed. Can. J. Chem. 67, 720 (1989).OpCrant ?I 25"C, dans des solutions ?I 80-90% P/P d'acide sulfurique, on a ttudit les sulfonations homogknes des derives de la P-carboline que sont le norharmane (2), l'harmane (3), l'harmine (4), l'harmol (S), le N,Nf-dimtthylharmane (6) et l'harmaline (7). Les spectres ultraviolet-visible et rksonance magnCtique nucltaire du I3C et les analyses chimiques des mClanges rtactionnels montrent que tous les substrats CtudiCs ne fournissent que les produits substituis en C-6. Les rCactions de sulfonation des substrats qui ne sont pas substituCs sur le noyau benzinique ( 2 , 3 et 6) ou qui ne sont que partiellement aromatiques (7) se produisent par une attaque Clectrophile directe du cation H3S04+ sur le noyau benzknique du squelette de la P-carboline. La sulfonation des composCs 4 et 5 aux concentrations les plus faibles d'acide sulfurique se produisent sous l'effet de l'entitt H3SO4+ Avec une augmentation de la concentration d'acide sulfurique, il se produit un changement graduel de I'entitC responsable de la sulfonation, de H3S04+ ?I H2S207. On discute des divers mtcanismes de sulfonation.

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13C NMR des alcaloïdes des Strychnos: Les dérivés de l'harmane et de l'usambarensine

Cited by 33 publications

References 11 publications

Banisteriopsis caapi, a unique combination of MAO inhibitory and antioxidative constituents for the activities relevant to neurodegenerative disorders and Parkinson's disease

Banisteriopsis caapi, a unique combination of MAO inhibitory and antioxidative constituents for the activities relevant to neurodegenerative disorders and Parkinson's disease

A Simple, Rapid and Mild One Pot Synthesis of Benzene Ring Acylated and Demethylated Analogues of Harmine under Solvent-free Conditions

Sulfonation reactions of (β-carbolines

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