References of "Tchinda Tiabou, Alembert"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailTerpenoids from Phaulopsis imbricata (Acanthaceae)
Kengne, A.B.O.; Tene, M.; Tchinda Tiabou, Alembert ULg et al

in Journal of Medicinal Plants Research (2016), 10(10), 122-129

The whole plant of Phaulopsis imbricata (Forssk.) Sweet (Acanthaceae) was collected at Bansoa, Cameroon, shade dried and extracted by maceration in methanol. This study was carried out to isolate ... [more ▼]

The whole plant of Phaulopsis imbricata (Forssk.) Sweet (Acanthaceae) was collected at Bansoa, Cameroon, shade dried and extracted by maceration in methanol. This study was carried out to isolate secondary metabolites from this plant species that has not been investigated so far. Two lupane-type triterpenoids, one β-type carotenoid, one eudesmane-type sesquiterpenoid, and one sterol glycoside were isolated from the dried methanol extract using solvent partitioning, column chromatography and re-crystallization. They were identified as lupeol, betulin, (all-E)-lutein, cryptomeridiol, and sitosterol 3- O-β-D-glucopyranoside, respectively. The structures of the isolated compounds were elucidated on the basis of spectroscopic methods including 1D- and 2D- nuclear magnetic resonance (NMR), infrared (IR) and mass spectrometry (MS). This is the first report of these compounds from the genus Phaulopsis. To the best of our knowledge, P. imbricata is also the first species of the genus to be phytochemically studied. [less ▲]

Detailed reference viewed: 23 (8 ULg)
Full Text
Peer Reviewed
See detailChemical constituents from Erythrina droogmansiana (Fabaceae), radical scavenging and antibacterial potential of some extracts and compounds
Talla, Emmanuel; Yaya Gbaweng, Joël; Mokale, Laurel et al

in Natural Products : An Indian Journal (2016), 12(1), 12-20

A new ceramide, droogmansiamide (1), was isolated from methanolic extract of roots wood of Erythrina droogmansiana, with eight known compounds namely 3-(3’,4’-methylenedioxyphenyl)-2,3-epoxypropanol (2 ... [more ▼]

A new ceramide, droogmansiamide (1), was isolated from methanolic extract of roots wood of Erythrina droogmansiana, with eight known compounds namely 3-(3’,4’-methylenedioxyphenyl)-2,3-epoxypropanol (2), erythrinasinate A (3), erythrinasinate B (4), abyssinone-IV-4'-methylether (5), erythrabyssin (6), phaseollidin (7), 4’-methoxylicoflavanone (8) and abyssinone-V-4'-methylether (9) respectively from methanolic extract of roots wood and EtOAc extract of roots bark of the same plant. Their structures were elucidated using spectroscopic methods (MS, NMR and IR) and by comparison with some data found in literature. Free radical scavenging (DPPH) and antibacterial potentials of extracts and compounds were also evaluated in this work. For radical scavenging, results showed that it is phaseollidin (7) which is responsible of radical scavenging potential in the ethyl acetate extract of roots barks with value of 1.31 mg/ml; for antibacterial, one of the tested compounds abyssinone-IV-4'-methylether (5) exhibited antibacterial activities against two strains: Providencia stuartiiATCC 29916 and Enterobacter aerogenes ATCC 13048 with MIC values of 25μg/ml. [less ▲]

Detailed reference viewed: 37 (3 ULg)
See detailEthnopharmacology and malaria in Africa
Frederich, Michel ULg; Jansen, Olivia ULg; Muganga, raymond et al

Conference (2015, July 12)

According to the last World Malaria Report [1], there were 584 000 deaths for 198 millions malaria cases worldwide in 2013. Particularly, the disease caused an estimated 437 000 African children died ... [more ▼]

According to the last World Malaria Report [1], there were 584 000 deaths for 198 millions malaria cases worldwide in 2013. Particularly, the disease caused an estimated 437 000 African children died before their fifth birthday, still in 2013. Malaria is caused by a parasite, Plasmodium sp. and transmitted by Anopheles mosquitoes. The problem of parasite resistance towards common available medicines such as chloroquine, mefloquine, quinine, is increasing. In this context, the vegetal kingdom remains the main source of pharmacologically active compounds against this parasitic infection as attested by the famous quinine, isolated from Cinchona sp., artemisinin extracted from Artemisia annua and also atovaquone derived from lapachol found in several Bignoniaceae. All these substances are related to plants with traditional use against fever and malaria. Beside these well-known examples, various new antiplasmodial compounds are frequently discovered from Nature, particularly following an ethnopharmacological approach, as reviewed by several authors in recent years [2-6]. Then, the pharmacological and phytochemical study of plants from traditional pharmacopoeias can be of first interest not only to discover new antimalarial “lead compounds”, but also to valorize local vegetal species whose efficacy and safety would have been demonstrated in laboratory and clinical investigations [7]. As demonstrated in several works from Willcox [8], better knowledge of plants from traditional pharmacopoeias and local valorization of validated traditional remedies in Improved Traditional Medicine (ITM) could allow the access to effective, standardized, available and affordable therapeutics for management of malaria by local populations. After this introductive section, the second part of the talk will be dedicated to the presentation of some results obtained in Liège with Dicoma tomentosa from Burkina-Faso [9], Strychnos icaja from Cameroun [10] and Terminalia mollis from Rwanda [11]. 1. WHO, World Malaria Report 2014, December 2014, Geneva (http://www.who.int/malaria/publications/world_malaria_report_2014/en/). 2. Batista R, Silva Ade J Jr, de Oliveira AB: Plant-derived antimalarial agents: new leads and efficient phytomedicines. Part II. Non-alkaloidal natural products. Molecules 2009, 14:3037-72. 3. Bero J, Frédérich M, Quetin-Leclercq J : Antimalarial compounds isolated from plants used in traditional medicine. Journal of Pharmacy and Pharmacology 2009, 61:1401–1433. 4. Bero J and Quetin-Leclercq J: Natural products published in 2009 from plants traditionally used to treat malaria. Planta Medica 2011, 77:631-40. 5. Kaur K, Jain M, Kaur T, Jain R: Antimalarials from nature. Bioorganic & Medicinal Chemistry 2009, 17:3229–3256. 6. Nogueira CR and Lopes LMX: Antiplasmodial Natural Products. Molecules 2011, 16:2146-2190 7. Ginsburg H and Deharo E: A call for using natural compounds in the development of new antimalarial treatments – an introduction. Malaria Journal 2011, 10 (suppl. 1):S1 8. Willcox M, Graz B, Falquet J, Diakite C, Giani S, Diallo D: A “reverse pharmacology” approach for developing an antimalarial phytomedicine. Malaria journal 2011, 10(suppl1):S8 9. Jansen, O., Tits, M., Angenot, L., Nicolas, J.-P., De Mol, P., Nikiema, J.-B., & Frédérich, M : Anti-plasmodial activity of Dicoma tomentosa (Asteraceae) and identification of urospermal A-15-O-acetate as the main active compound. Malaria Journal 2012, 11, 289. 10. Tchinda, A. T., Jansen, O., Nyemb, J.-N., Tits, M., Dive, G., Angenot, L., & Frédérich, M. Strychnobaillonine, an unsymmetrical bisindole alkaloid with an unprecedented skeleton from Strychnos icaja roots. Journal of Natural Products 2014, 77(4), 1078–82. 11. Muganga, R., Angenot, L., Tits, M., & Frédérich, M : In vitro and in vivo antiplasmodial activity of three Rwandan medicinal plants and identification of their active compounds. Planta Medica 2013, 80(6), 482-489. [less ▲]

Detailed reference viewed: 125 (11 ULg)
Full Text
Peer Reviewed
See detailMultiplicity editing in long-range heteronuclear correlation NMR experiments: Application to natural products
Sauri, Josep; Sistare, E.; Frederich, Michel ULg et al

Poster (2015, February)

Detailed reference viewed: 28 (6 ULg)
Full Text
Peer Reviewed
See detailTwo new aromadendrane sesquiterpenes from the stem bark of Alafia multiflora
Tchinda Tiabou, Alembert ULg; Tsala, David E.; Nnanga, Nga et al

in Natural Product Communications (2014), 9(12), 1673-1675

Detailed reference viewed: 47 (15 ULg)
Full Text
Peer Reviewed
See detailAntiplasmodial anthraquinones and hemisynthetic derivatives from the leaves of Tectona grandis (Verbenaceae)
Kopa, T.K.; Tchinda Tiabou, Alembert ULg; Tala, M.F. et al

in Phytochemistry Letters (2014), 8

Chemical investigation of the methanol extract of the leaves of Tectona grandis led to the isolation of one new anthraquinone derivative, grandiquinone A (3-acetoxy-8-hydroxy-2-methylanthraquinone) (1 ... [more ▼]

Chemical investigation of the methanol extract of the leaves of Tectona grandis led to the isolation of one new anthraquinone derivative, grandiquinone A (3-acetoxy-8-hydroxy-2-methylanthraquinone) (1), along with nine known compounds: 5,8-dihydroxy-2-methylanthraquinone (2), hydroxysesamone (3), 3-hydroxy-2-methylanthraquinone (4), quinizarine (5), betulinic acid (6), ursolic acid (7), tectograndone (8), corosolic acid (9) and sitosterol 3-O-β-d-glucopyranoside (10). Compounds 2 and 3 were isolated for the first time from the leaves of this plant, while 5 has never been reported from the genus Tectona. Hydroxysesamone (3) and tectograndone (8) were subjected to cyclisation and acetylation reactions to afford two hemisynthetic derivatives, 6,9-dihydroxy-2,2-(dimethyldihydropyrano)-3,4-dihydro-2H-benzo[g]chromene-5,10-dione (11) and acetyltectograndone (12) respectively, which are reported here for the first time. The ethyl acetate-soluble portion, some of the isolated compounds and hemisynthetic derivatives were evaluated for their antiplasmodial activity against the multidrug-resistant Dd2 strain of Plasmodium falciparum. Compound 3 showed a prominent activity, while 2, 8, 9, 11 and 12 showed significant in vitro anti-malarial activity. Compound 1 was weakly active in this test. The structures of the compounds were elucidated by spectroscopic methods and comparison of the data with the literature. [less ▲]

Detailed reference viewed: 53 (4 ULg)
Full Text
Peer Reviewed
See detailAntioxidant Activity of Flavonoids Isolated From the Fruits of Xylopia parviflora (A. Rich.) Benth
Tchinda Tiabou, Alembert ULg; Agbor, GA; Tsala, DE et al

in International Journal of Pharmaceutical Sciences and Drug Research (2014), 6

Detailed reference viewed: 34 (6 ULg)
Full Text
Peer Reviewed
See detailAntioxidant Activity of Compounds Isolated from the Root Woods of Erythrina droogmansiana
Yaya, AJG; Feumba, RD; Emmanuel, T et al

in International Journal of Pharmaceutical Sciences and Drug Research (2014), 6(2), 160-163

The aim of this study was to isolate, to characterize secondary metabolites from methanolic extract of the root woods of Erythrina droogmansiana and to assess the antioxidant activity of the crude extract ... [more ▼]

The aim of this study was to isolate, to characterize secondary metabolites from methanolic extract of the root woods of Erythrina droogmansiana and to assess the antioxidant activity of the crude extract and isolated compounds. The phytochemical study led to the isolation of 3-(3’,4’-methelenedioxyphenyl)-2,3-epoxypropanol (1), asperphenamate (2) and three flavonoids namely genistein, diadzein and 4’,5,7-trihydroxy-8-prenylisoflavone. These compounds were characterized using their 1H NMR, 13C NMR, HMBC, HSQC, COSY, mass spectral and the literature. To evaluate antioxidant activity of crude extract and isolated compounds, the radical scavenging (DPPH) and Ferric Reducing Ability Power (FRAP) were performed using ascorbic acid as standard. Compounds 1 and 2 showed moderate radical scavenging potential with IC50 value of 3.14 and 3.31 mg/ml respectively, and moderate reducing power ability with value of 0.14±0.01 mgAAE/mg and 0.21±0.01 mgAAE/mg respectively. The more active compound was genistein (3) with IC50 value of 1.96 mg/ml for the DPPH radical scavenging potential and 0.24±0.02 mgAAE/mg for its ability to reduce iron. [less ▲]

Detailed reference viewed: 62 (7 ULg)
Full Text
Peer Reviewed
See detailStrychnobaillonine, an Unsymmetrical Bisindole Alkaloid with an Unprecedented Skeleton from Strychnos icaja Baill. Roots
Tchinda Tiabou, Alembert ULg; Jansen, Olivia ULg; Nyemb, Jean-Noel et al

in Journal of Natural Products (2014), 77

Detailed reference viewed: 47 (10 ULg)
Full Text
Peer Reviewed
See detailAlkaloids from the stem bark of Strychnos icaja
Tchinda Tiabou, Alembert ULg; Tamze, Victorine; Ngono, Annie R N et al

in Phytochemistry Letters (2012), 5(1), 108-113

A comprehensive phytochemical study of the stem bark of Strychnos icaja was done for the first time and led to the isolation of two new monoindole alkaloids 15-hydroxyvomicine (1) and 12-methoxyicajine (2 ... [more ▼]

A comprehensive phytochemical study of the stem bark of Strychnos icaja was done for the first time and led to the isolation of two new monoindole alkaloids 15-hydroxyvomicine (1) and 12-methoxyicajine (2) along with 13 known alkaloids: the monoindoles N-methyl-sec-iso-pseudostrychnine (3), vomicine (4), icajine (5), 19,20-α-epoxy-12-methoxyicajine (6), 19,20-α-epoxy-12,15-dihydroxy-11-methoxyicajine (7), 19,20-α-epoxy-15-hydroxynovacine (8), 15-hydroxyicajine (9), 12-hydroxystrychnine (10), strychnine (11) and the tertiary bisindoles sungucine (12), isosungucine (13), strychnogucine C (14) and bisnordihydrotoxiferine (15). Apart from 10 and 11, the other alkaloids were isolated for the first time from the stem bark of this plant. The hemisynthetic derivative, Nb-chloromethosungucine (16) and the previously reported synthetic compound 3 were isolated from a natural source for the first time. Fractions and some isolated compounds were tested against the chloroquine-sensitive 3D7 strain of Plasmodium falciparum. The bisindole alkaloids were most active with IC50 ranging from 0.72 to 3.41 μg/ml whilst the monomers 1 and 3 were slightly active (IC50 39.92 and 40.27 μg/ml respectively) and 6 inactive. The structures of the compounds were determined based on the analysis of their spectral data. The full 1H and 13C NMR data of compounds 3, 6 and 7 are also reported in the present work for the first time. [less ▲]

Detailed reference viewed: 99 (23 ULg)
Full Text
Peer Reviewed
See detailArdisikivuoside, a new triterpenoid saponin from Ardisia kivuensis (Mysinaceae)
Ndontsa, Blanche; Tchinda Tiabou, Alembert ULg; Teponno, Rémy et al

in Natural Product Communications [=NPC] (2012), 7

Detailed reference viewed: 70 (5 ULg)
Full Text
Peer Reviewed
See detailAntiparasitic activities of two sesquiterpenic lactones isolated from Acanthospermum hispidum D.C
Ganfon; Bero, Joanne; Tchinda Tiabou, Alembert ULg et al

in Journal of Ethnopharmacology (2012), 141(0), 411-417

Ethnopharmacological relevance : Aerial parts of Acanthospermum hispidum D.C. are often used by traditional healers in Benin for various diseases and especially for malaria Aim of the study : Identify ... [more ▼]

Ethnopharmacological relevance : Aerial parts of Acanthospermum hispidum D.C. are often used by traditional healers in Benin for various diseases and especially for malaria Aim of the study : Identify active compounds from extracts of Acanthospermum hispidum D.CV. leaves previously shown to possess antimalarial properties and analyse in vivo activity and toxicity of crude extracts. Materials and methods : Compounds were isolated from aerial part of A. hispidum D.C. and structurally elucidated using extensive spectroscopic analysis. Antiplasmodial activity was evaluated in vitro against a chloroquinosensitive strain of Plasmodium falciparum (3D7) using the measurement of the plasmodial lactate dehydrogenase activity and in vivo against P. berghei berghei by the 4-days suppressive test. Selectivity of extract and purified compounds on Plasmodium parasites were evaluated by using MTT test on J774 macrophage like murine cells and WI38 human normal fibroblasts and also against two other parasites: Trypanosoma brucei brucei and Leishmania mexicana mexicana. Acute and sub-acute toxicities of a crude extract were evaluated on mice. Results : Two known sesquiterpenic lactones were isolated: 1 (15-acetoxy-8β-[(2-methylbutyryloxy)]-14-oxo-4, 5-cis-acanthospermolide) and 2 (9α-acetoxy-15-hydroxy-8β-(2-methylbutyryloxy) -14-oxo-4, 5-trans-acanthospermolide). 1 and 2 showed in vitro antiplasmodial activity against the chloroquino-sensitive strain (3D7) with IC50 of 2.9 ± 0.5 and 2.23 ± 0.09 μM respectively. Only 2 showed a high selectivity index (SI: 18.4) on Plasmodium compared to cytotoxicity against human fibroblasts cell line (WI38). 1 and 2 also showed interesting antiparasitic activities in vitro against Trypanosoma brucei brucei (IC50 of 2.45 ± 0.49 and 6.36 ± 1.42 μM respectively) and Leishmania mexicana mexicana (IC50 of 0.94 ± 0.05 and 2.54 ± 0.19 μM respectively). Furthermore, crude acidic water extract and fractions containing one of the two isolated compounds displayed a weak in vivo antimalarial activity against P. berghei berghei with a long half-life causing a delayed effect. In vivo acute (2000 mg/kg) and sub-acute (1000 mg/kg) toxicity tests on the crude acidic water extract did not show toxicity. Conclusion : Crude acidic water extract, fractions and pure isolated compounds from A.hispidum showed promising in vitro antiplasmodial activity. Despite our study did not show in vivo acute and subacute toxicities of the crude acidic water extract, its weak in vivo antimalarial activity and the in vitro cytoxicity of pure compounds and enriched extracts containing 1 and 2 indicate that the aerial parts of A. hispidum should be used with caution for malaria treatments. [less ▲]

Detailed reference viewed: 43 (2 ULg)
Full Text
Peer Reviewed
See detailAntiplasmodial Alkaloids from the Stem Bark of Strychnos malacoclados.
Tchinda Tiabou, Alembert ULg; Ngono, A. R.; Tamze, V. et al

in Planta Medica (2012), 78

From the stem bark of STRYCHNOS MALACOCLADOS, one new bisindole alkaloid, 3-hydroxylongicaudatine Y ( 1), was isolated along with the known alkaloids vomicine ( 2), bisnordihydrotoxiferine ( 3), divarine ... [more ▼]

From the stem bark of STRYCHNOS MALACOCLADOS, one new bisindole alkaloid, 3-hydroxylongicaudatine Y ( 1), was isolated along with the known alkaloids vomicine ( 2), bisnordihydrotoxiferine ( 3), divarine ( 4), longicaudatine ( 5), longicaudatine Y ( 6), and longicaudatine F ( 7). All the compounds were tested for their antimalarial activity against the chloroquine-sensitive 3D7 and -resistant W2 strains of PLASMODIUM FALCIPARUM. Longicaudatine was the most active compound with IC (50) values of 0.682 and 0.573 microM, respectively. The activity of compounds 1, 3, 4, 6, and 7 against the two strains ranged from 1.191 to 6.220 microM and 0.573 to 21.848 microM, respectively. Vomicine ( 2), the only monomer isolated, was inactive. The alkaloids of the longicaudatine-type ( 1, 5- 7) were more active than those of the caracurine-type ( 3- 4). The presence of the ether bridge in the molecule seems to increase the antiplasmodial activity. Compounds 1, 5, and 7 were tested against the WI-38 human fibroblast cell line. Longicaudatine was the most cytotoxic compound with an IC (50) of 2.721 microM. Longicaudatine F was 40-46 times more active against the two strains of P. FALCIPARUM than against the human fibroblasts and was thus considered as the more selective alkaloid. The structures of the compounds were determined based on the analysis of their spectral data. [less ▲]

Detailed reference viewed: 90 (17 ULg)
Full Text
Peer Reviewed
See detailPhenolic Compounds and Terpenoids from Hypericum lanceolatum
Wabo, H. K.; Kowa, T. K.; Lonfouo, A. H. et al

in Records of Natural Products (2012), 6(2), 94-100

Detailed reference viewed: 61 (9 ULg)
Full Text
Peer Reviewed
See detailBioassay-guided isolation of antiplasmodial Strychnos alkaloids from the stem-bark of Strychnos icaja BAILLON
Tchinda Tiabou, Alembert ULg; Tamze, Victorine; Frederich, Michel ULg et al

in Planta Medica (2010, September), 76(12), 1305

Detailed reference viewed: 73 (1 ULg)