A 7,8-dihydro-8-hydroxypalmatine from Enantia chlorantha

Wafo, Pascal; Nyasse, Barthélémy; Fontaine, C.

doi:10.1016/s0031-9422(98)00382-3

Cited by 34 publications

(27 citation statements)

References 3 publications

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“…The proper detection of the OH signal is also important in the cases when pseudobases are claimed to be novel alkaloids. 23 Recently, pseudobases of the protoberberine alkaloids palmatine 24 and 2,3,9,10-dimethylenedioxy-1-hydroxyprotoberberine 25 have been reported to be isolated from plants. However, in both cases, the NMR spectra in CDCl 3 lacked the signals of OH hydrogens.…”

Section: Resultsmentioning

confidence: 99%

Structural studies of benzophenanthridine alkaloid free bases by NMR spectroscopy

Sečkářová

Marek

Dostál

et al. 2001

Magnetic Reson in Chemistry

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The free bases of eight quaternary benzo[c]phenanthridine alkaloids (chelerythrine, sanguilutine, chelirubine, chelilutine, sanguirubine, sanguinarine, nitidine and fagaronine) were investigated by 1 H and 13 C NMR spectroscopy. The pseudobases (the 6-hydroxy-5,6-dihydro derivatives) were found to be the only products of the alkalization of these alkaloids using sodium carbonate in DMSO-d 6 solution. This observation differs from the measurements of preparative free bases in CDCl 3 solution, where the structures of the bimolecular aminoacetals were unequivocally confirmed. According to the results obtained, in biological systems, in the presence of excess of water and ions, free bases of the investigated alkaloids are assumed to adopt the pseudobase (6-hydroxy derivative) structure. In contrast, in less polar media (C 6 D 6 , CDCl 3 ), the formation of the bimolecular aminoacetal structure is preferred.

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Section: Resultsmentioning

confidence: 99%

Structural studies of benzophenanthridine alkaloid free bases by NMR spectroscopy

Sečkářová

Marek

Dostál

et al. 2001

Magnetic Reson in Chemistry

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“…This plant is commonly found in the forest and coastal areas of West Africa, and the Democratic Republic of Congo (Vivien and Faure, 1985;Iwu, 1993). Wafo et al (1999) reported the antiviral activity of aqueous extract of the dried stem bark of the plant, while the potentials of the plant extract in relieving pyrogen-induced fever in albino rats was reported by Agbaje and Onabanjo (1988). In Cameroon, stem bark extract is used to treat jaundice and urinary tract infections (Adjanohoun et al, 1996).…”

Section: Introductionmentioning

confidence: 95%

Antibacterial potentials of aqueous extract of Enantia chlorantha stem bark

Adesokan¹,

Akanji²,

Yakubu³

2007

Afr. J. Biotechnol.

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The antibacterial potentials of aqueous extract of Enantia chlorantha stem bark at varying concentrations of 50, 100 and 150 mg/ml was investigated by measuring the zones of inhibition produced after incubation on nutrient agar. Staphylococcus aureus and Bacillus substilis, Escherichia coli, Salmonella typhymurium and Pseudomonas aeruginosa were used as test organisms. The results revealed that the zones of inhibition on the bacterial isolates increased (P < 0.05) as the concentration of the plant extract increased. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration produced by the extract on the gram positive bacteria were significantly lower (P < 0.05) than the gram negative bacteria. The results revealed that the aqueous extract of Enantia chlorantha stem bark possessed antibacterial activities on the clinical isolates with more antibacterial effect on the gram-positive than the gram-negative bacteria. The identified alkaloids might be responsible for the antibacterial activities.

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“…Previous studies showed that a protoberberine-type alkaloid (7,8-dihydro-8-hydroxypalmatine (PAL)) (Wafo et al, 1999) prepared from the stem bark of E. chlorantha possessed prophylactic antiulcer effects and healing effects on chronic acetic acid-induced gastric ulcers (Tan et al, 2000). The same compound was recently found to possess in vitro and in vivo anti-Helicobacter properties Tan et al, 2006).…”

Section: Discussionmentioning

confidence: 99%