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Maître de Conférences
Activité scientifique
Profil chercheur
Enseignant-chercheur à l’Université de Yaoundé I. Grade : Maître de Conférences.
Publications scientifiques
Miraine K. Ndacnou, Pantaléon Ambassa, Jean‐Bosco Saha Tchinda, Eddy Leonard Ngonkeu Mangapche, Félix Keumedjio, Didier Begoude Boyoguemo
Industrial Crops and Products
Victor Kuete, Dominique Ngnintedo, Ghislain W. Fotso, Oğuzhan Karaosmanoğlu, Bonaventure T. Ngadjui, Félix Keumedjio et 3 autre(s)
BMC Complementary and Alternative Medicine
BACKGROUND: Despite the remarkable progress in cancer therapy in recent years, this disease still remains a serious public health concern. The use of natural products has been and continues to be one of the most effective ways to fight malignancies. The cytotoxicity of 14 compounds from African medicinal plants was evaluated in four human carcinoma cell lines and normal fibroblasts. The tested samples included: β-spinasterol (1), friedelanone (2), 16β-hydroxylupeol (3), β-amyrin acetate (4), lupeol acetate (5), sequoyitol (6), rhamnitrin (7), europetin 3-O-rhamnoside (8), thonningiol (9), glyasperin F (10), seputhecarpan B (11), seputhecarpan C (12), seputhecarpan D (13) and rheediaxanthone A (14). METHODS: The neutral red uptake (NR) assay was used to evaluate the cytotoxicity of samples; caspase-Glo assay, flow cytometry for cell cycle analysis and mitochondrial membrane potential (MMP) as well as spectrophotometry to measure levels of reactive oxygen species (ROS) were performed to detect the mode of action of compounds 9 and 13 in MCF-7 breast adenocarcinoma cells. RESULTS: values varied from 0.36 μM (against MCF7 cells) to 5.65 μM (towards colon carcinoma DLD-1 cells) for 9, from 9.78 μM (against MCF7 cells) to 67.68 μM (against HepG2 cells) for 13 and 0.18 μM (towards HepG2 cells) to 72 μM (towards Caco-2 cells) for the reference drug, doxorubicin. Compounds 9 and 13 induced cell cycle arrest in Go/G1 whilst doxorubicin induced arrest in G2/M. The two molecules (9 and 13) also induced apoptosis in MCF-7 cells through activation of caspases 3/7 and 9 as well as enhanced ROS production. CONCLUSION: Compounds 9 and 13 are good cytotoxic phytochemicals that should be explored more in future to develop a cytotoxic drug to fight human carcinoma.
Armelle T. Mbaveng, Ghislain W. Fotso, Dominique Ngnintedo, Victor Kuete, Bonaventure T. Ngadjui, Félix Keumedjio et 2 autre(s)
Phytomedicine
Dominique Ngnintedo, Ghislain W. Fotso, Victor Kuete, Frederic Nana, Louis P. Sandjo, OÄuzhan KaraosmanoÄlu et 5 autre(s)
Figshare
Additional file 1. Comparision of 1H and 13C NMR spectra of seputhecarpan C 1 and seputhecapan B (Fotso et al, 2013). These spectra clearly show the presence of an additional methoxyle group in seputhecarpan C.
Dominique Ngnintedo, Ghislain W. Fotso, Victor Kuete, Frederic Nana, Louis P. Sandjo, OÄuzhan KaraosmanoÄlu et 5 autre(s)
Figshare
Additional file 1. Comparision of 1H and 13C NMR spectra of seputhecarpan C 1 and seputhecapan B (Fotso et al, 2013). These spectra clearly show the presence of an additional methoxyle group in seputhecarpan C.
Abdou Tchoukoua, Sandjo Louis Pergaud, Félix Keumedjio, Ngadjui Bonaventure, Tchaleu, Gilbert Kirsch
HAL (Le Centre pour la Communication Scientifique Directe)
Abdou Tchoukoua, Louis P. Sandjo, Félix Keumedjio, Bonaventure T. Ngadjui, Gilbert Kirsch
Chemistry of Natural Compounds
Frédéric Nana, Louis P. Sandjo, Félix Keumedjio, Pantaléon Ambassa, Rizwana Malik, Victor Kuete et 3 autre(s)
Journal of the Brazilian Chemical Society
Chemical investigation of the stem bark of Ficus glumosa (Moraceae) yielded two new ceramides (2R,7E)-2-hydroxy-N-[(2S,3S,4R)-1,3,4-trihydroxyhexadecan-2-yl]hexacos-7-enamide and (2R)-N-{(2S,3S,4R,9Z)-1-O-[(β-D-glucopyranosyl]-3,4-dihydroxyheptadec-9-en-2-yl}-2-hydroxypentacosanamide together with twenty one known compounds. The structures were established using NMR data, mass spectrometry, chemical transformation and by comparison with the reported data. Twenty one compounds were further tested against the prostate cancer PC-3 cell line and six of them revealed cytotoxic effect. Dongnoside E was the most active compound with an IC50 0.75 µmol L-1 against the cancer cells line PC-3 while the reference drug doxorubicin displayed 0.91 µmol L-1. This compound also proved to inhibit the cell growth of the fibrosarcoma cancer HT1080 (IC50 0.7 µmol L-1).
Frédéric Nana, Louis P. Sandjo, Félix Keumedjio, Victor Kuete, Bonaventure T. Ngadjui
Natural Product Research
A new aldol ester named 17-O-triacontanoylheptadecanal (1) was isolated from the aerial part of Mimosa invisa (Mimosaceae) together with eight known compounds identified as β-sitosterol (2), α-amyrine (3), lupeol (4), 4'-O-methylepinumisoflavone (5), alpinumisoflavone (6), betulinic acid (7), 3-O-β-D-glucopyranoside of sitosterol (8) and epirobinetinidol (9). The structures of compounds were determined on the basis of NMR and mass spectrometry data as well as by comparing the data reported in the literatures. The antimicrobial activities of the crude extract and compounds 1 and 9 were investigated against seven microbial species. The natural products showed moderate activities compared to that of the crude extract.
Louis P. Sandjo, Abdou Tchoukoua, Hippolyte Nga Ntede, Mehdi Yemloul, Enrico Perspicace, Félix Keumedjio et 3 autre(s)
Journal of the American Oil Chemists Society
Abstract To highlight the role of plants in traditional healing, the leaves and the stems of cultivated Triumfetta cordifolia were phytochemically studied yielding a new nor‐ursane type ( 1 ), a new ceramide ( 2 ) and a new piperidinic ceramide derivative ( 3 ) named, respectively, 2α,19α‐dihydroxy‐3‐oxo‐23‐nor‐urs‐12‐en‐28‐oic acid, (2 R )‐2‐hydroxy‐ N ‐[(2 S ,3 S ,4 R ,26 E )‐1,3,4‐trihydroxy‐26‐triaconten‐2‐yl] tetradecanamide and (2 R ,8 Z )‐2‐hydroxy‐{(2 S ,3 R ,5 R,6S )‐3,5‐dihydroxy‐6‐[(1 E ,5 Z )‐hexadeca‐1,5‐dienyl]‐2‐(β‐ d ‐glucopyranosyloxy)methyl piperidine‐1‐yl} tetracos‐8‐enamide ( 3 ). These were obtained together with lupeol ( 4 ), stigmasterol ( 5 ), 3‐ O ‐ β ‐ d ‐glucopyranoside of β ‐sitosterol ( 6 ), tormentic acid ( 7 ) from stems and heptadecanoic acid ( 8 ), β ‐carotene ( 9 ), oleanolic acid ( 10 ), and 24‐hydroxytormentic acid ( 11 ) from leaves. The structures were determined on the basis of NMR data ( 1 H‐, 13 C‐, 2D‐NMR analyses), mass spectrometry and confirmed by chemical transformations as well as comparison of spectral data with those reported in the literature. The FRAP method was used to evaluate the antioxidant activity of fractions collected from flash chromatography and isolated compounds. Among the fractions, four reduced Fe III ‐TPTZ to Fe II ‐TPTZ while isolated pure compounds showed no activity.
Victor Kuete, Frédéric Nana, Bathélémy Ngameni, Armelle T. Mbaveng, Félix Keumedjio, Bonaventure T. Ngadjui
Journal of Ethnopharmacology
Hervé Martial Poumale Poumale, Rodrigue T. Kengap, Jean Claude Tchouankeu, Félix Keumedjio, Hartmut Laatsch, Bonaventure T. Ngadjui
ChemInform
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
M P Poumale Herve, Towanou Rodrigue, Tchouankeu Jean Claude, Félix Keumedjio, Hartmut Laatsch, T Ngadjui Bonaventure
Zeitschrift für Naturforschung B
Hervé Martial Poumale Poumale, Rodrigue T. Kengap, Jean Claude Tchouankeu, Félix Keumedjio, Hartmut Laatsch, Bonaventure T. Ngadjui
Zeitschrift für Naturforschung B
Abstract Two new pentacyclic triterpenes 8,26-cyclo-urs-21-en-3β, 20β-diol (1) and 3β-acetoxy-8.26- cyclo-ursan-20β-ol (2) together with 3-friedelanone, oleanolic acid, betulinic acid, lupeol acetate, α- and β-amyrine, S.SJ^'-tetrahydroxyflavane, and 3,5,7,3',4'-pentahydroxyflavane were isolated from the stem bark of Ficus cordata (Moraceae). The structures of these secondary metabolites were established using ID and 2D NMR spectra and by comparison with published data or with authentic samples. Compounds 1 and 2 exhibited weak antibacterial and no antifungal activity.
Bathélemy Ngameni, Jean Watchueng, Fabrice Fekam Boyom, Félix Keumedjio, Bonaventure T. Ngadjui, Jiří Gut et 2 autre(s)
ARKIVOC
The ever widening level of Plasmodium falciparum resistance to antimalarials has led to the search of alternative therapies. In this context, any resources that can help alleviate the burden of the deadly malaria; including the search for new plant-derived biologically active ingredients are worthy of investigation. Amongst these, naturally occurring and synthetic chalcones have demonstrated promising potencies. In the present study, two diprenylated chalcones Bartericin A 1 and B 2, and four known natural products, stipulin 3, 4-hydroxylonchocarpin 4, isobavachalcone 5 and kanzonol B 6 were isolated from the twigs of Dorstenia barteri var. subtriangularis (Moraceae) by means of chromatographic methods. The structures of the purified compounds were elucidated by spectroscopic methods, mainly 1D and 2D-NMR spectroscopy. These compounds (1-6) were evaluated in culture against the W2 strain of P. falciparum. The evaluated compounds were found to be active in vitro against P. falciparum, 1, 3 and 4 demonstrating particular potencies with relatively low IC 50 values (2.15 M, 5.13 M and 3.36 M respectively). The observed activities confirmed the chalcones as potential leads for the development of antimalarials.
Bonaventure T. Ngadjui, Jean Watchueng, Félix Keumedjio, Bathélémy Ngameni, Ingrid Konga Simo, Berhanu M. Abegaz
Phytochemistry
Bonaventure T. Ngadjui, Berhanu Abegaz, Félix Keumedjio, Gabriel N. Folefoc, Gilbert W.F Kapche
Phytochemistry
Fabrice Fekam Boyom, Félix Keumedjio, Pierre Michel Jazet Dongmo, BT Ngadjui, P. H. Amvam Zollo, Chantal Menut et 1 autre(s)
Flavour and Fragrance Journal
Abstract Three essential oils obtained by hydrodistillation from the leaves, roots and stem barks of Croton zambesicus Muell. Arg. (Euphorbiaceae) were analysed by GC and GC–MS. This West Tropical African species has many uses, especially as a drug source for the cure of many ailments. The three organs were found to contain 0.17–0.34% yield of oil. The qualitative composition of the three types of oil were found to be similar; those from the leaves and stem bark were found to be rich in monoterpenes (69.6% and 75.2% respectively), while the root bark oil contained 57.0% sesquiterpenes. The root and stem barks oils were found to be rich in oxygen‐containing compounds, with spathulenol (14.0%) and linalool (33.8%) as the major components, respectively. The leaf oil was found to contain mainly hydrocarbons and only 11.6% of oxygenated compounds. Copyright © 2002 John Wiley & Sons, Ltd.
Bonaventure T. Ngadjui, Gabriel G. Folefoc, Félix Keumedjio, Étienne Dongo, Beiban L. Sondengam, Joseph D. Connolly
ChemInform
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
Bonaventure T. Ngadjui, Gabriel G. Folefoc, Félix Keumedjio, Étienne Dongo, Beiban L. Sondengam, Joseph D. Connolly
Phytochemistry
Samuel F. Kimbu, Félix Keumedjio, Lucas B. Sondengam, Joseph D. Connolly
Phytochemistry
Dominique Ngnintedo, Ghislain W. Fotso, Victor Kuete, Frederic Nana, Louis P. Sandjo, OÄuzhan KaraosmanoÄlu et 5 autre(s)
Figshare
Additional file 2. 1H and 13C NMR spectra of seputhecarpan D. 2.
Dominique Ngnintedo, Ghislain W. Fotso, Victor Kuete, Frederic Nana, Louis P. Sandjo, OÄuzhan KaraosmanoÄlu et 5 autre(s)
Figshare
Additional file 2. 1H and 13C NMR spectra of seputhecarpan D. 2.
Dominique Ngnintedo, Ghislain W. Fotso, Victor Kuete, Frederic Nana, Louis P. Sandjo, Oğuzhan Karaosmanoğlu et 5 autre(s)
Figshare
Additional file 3. 1H and 13C NMR spectra of pythylopyrone A 3 showing the signals of the additional γ,γ-dimethylallyle group in position 4 of the molecule.
Dominique Ngnintedo, Ghislain W. Fotso, Victor Kuete, Frederic Nana, Louis P. Sandjo, Oğuzhan Karaosmanoğlu et 5 autre(s)
Figshare
Additional file 3. 1H and 13C NMR spectra of pythylopyrone A 3 showing the signals of the additional γ,γ-dimethylallyle group in position 4 of the molecule.
Dominique Ngnintedo, Ghislain W. Fotso, Victor Kuete, Frederic Nana, Louis P. Sandjo, Oğuzhan Karaosmanoğlu et 5 autre(s)
Figshare
Additional file 4. 1H and 13C NMR spectra of mundulea lactone 4 as well as all the 2D NMR data justifying the revision of the NMR assignment of this compound as shown in Table 2.
Dominique Ngnintedo, Ghislain W. Fotso, Victor Kuete, Frederic Nana, Louis P. Sandjo, Oğuzhan Karaosmanoğlu et 5 autre(s)
Figshare
Additional file 4. 1H and 13C NMR spectra of mundulea lactone 4 as well as all the 2D NMR data justifying the revision of the NMR assignment of this compound as shown in Table 2.
Dominique Ngnintedo, Ghislain W. Fotso, Victor Kuete, Frédéric Nana, Louis P. Sandjo, Oğuzhan Karaosmanoğlu et 5 autre(s)
Chemistry Central Journal
Ptycholobium is a genus related to Tephrosia which comprises only three species. Compared to Tephrosia , which has been phytochemically and pharmacologically studied, Ptycholobium species have only few or no reports on their chemical constituents. Moreover, no studies on the cytotoxic activities of its secondary metabolites have been previously documented. From the non polar fractions of the roots bark of Ptycholobium contortum (syn Tephrosia contorta ), two new pterocarpans: seputhecarpan C 1 and seputhecarpan D 2 and a new pyrone derivative, ptycholopyrone A 3 were isolated. Alongside, five known compounds identified as 3-α,α-dimethylallyl-4-methoxy-6-styryl-α-pyrone or mundulea lactone 4 , glyasperin F 5 , seputhecarpan A 6 , seputheisoflavone 7 and 5- O -methyl-myo-inositol or sequoyitol 8 were also obtained. Their structures were established by the mean means of spectroscopic data in conjunction to those reported in literature. The NMR assignment of the major compound mundulea lactone 4 is revised in this paper. In addition, the cytotoxicity of the isolated metabolites was evaluated on two lung cancer cell lines A549 and SPC212. 8 was not active while compounds 1, 2, 4–7 displayed antiproliferative effects against the two carcinoma cell lines with IC 50 values below 75 µM. IC 50 values below 10 µM were obtained for 4, 6 and 7 on SPC212 cells. Based on the obtained results, Ptycholobium contortum turns to be a rich source of phenolic metabolites among them some bearing prenyl moieties. This study reports for the first time the isolation of pyrone derivatives 3 and 4 from Ptycholobium genus. The cytotoxicity observed for the isolate is also reported for the first time and shows that 4, 6 and 7 could be chemically explored in order to develop a hit candidate against lung cancer. Two new pterocarpans and a new pyrone derivative with cytotoxic activities from ptycholobium contortum (N.E.Br.) Brummitt (Leguminosae): revised NMR assignment of mundulea lactone.
Profil chercheur
Publications scientifiques
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