References of "Frederich, Michel"
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See detailPolyphenol Content and Modulatory Activities of Some Tropical Dietary Plant Extracts on the Oxidant Activities of Neutrophils and Myeloperoxidase
Tsumbu, César Ndele ULg; Deby-Dupont, Ginette; Tits, Monique ULg et al

in International Journal of Molecular Sciences (2012), 13(1), 628-650

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See detailUNDERSTANDING THE INTERACTIONS BETWEEN ARTEMISININ AND CYCLODEXTRINS: SPECTROSCOPIC STUDIES AND MOLECULAR MODELING
Zime Diawara, Hermine; Dive, Georges ULg; Piel, Géraldine ULg et al

in Journal of Inclusion Phenomena and Molecular Recognition in Chemistry (2012), 74(1), 305-315

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See detailLC–SPE–NMR–MS analysis of Strychnos usambarensis fruits from Rwanda
Cao, Martine ULg; Muganga, Raymond; Nistor, Iolanda ULg et al

in Phytochemistry Letters (2012), 5(0), 170-173

The novelty of the present work lies in the characterization of akagerine and palicoside in Strychnos usambarensis fruits by a hyphenated analytical method combining high-performance liquid chromatography ... [more ▼]

The novelty of the present work lies in the characterization of akagerine and palicoside in Strychnos usambarensis fruits by a hyphenated analytical method combining high-performance liquid chromatography coupled with solid-phase extraction (SPE), mass spectrometry (HPLC–MS) and NMR spectroscopy. Akagerine was already known in S. usambarensis roots but palicoside is described for the first time in the species. [less ▲]

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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 ▲]

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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 ▲]

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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

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See detail17-O-Actetyl-10-hydroxycorynantheol, a selective antiplasmodial alkaloid isolated from Strychnos usambarensis leaves
Cao, Martine ULg; Muganga, Raymond ULg; Tits, Monique ULg et al

Conference (2011, December 13)

In the course of our investigations on Strychnos usambarensis leaves in order to isolate isostrychnopentamine, the main alkaloid responsible for the antiplasmodial activity of the plant, a new tertiary ... [more ▼]

In the course of our investigations on Strychnos usambarensis leaves in order to isolate isostrychnopentamine, the main alkaloid responsible for the antiplasmodial activity of the plant, a new tertiary indolic alkaloid has been isolated: 17-O-acetyl, 10-hydroxycorynantheol 1. Its structure was determined by means of spectroscopic and spectrometric methods such as UV, IR, CD, NMR and ESI-MS. 17-O-acetyl, 10-hydroxycorynantheol 1 is one of the most active monomeric indole alkaloid known to date showing an in vitro activity against Plasmodium falciparum close to 5 µM and a high selectivity. [less ▲]

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See detail17-O-Acetyl,10-hydroxycorynantheol, a Selective Antiplasmodial Alkaloid Isolated from Strychnos usambarensis Leaves
Cao, Martine ULg; Muganga, Raymond ULg; Tits, Monique ULg et al

in Planta Medica (2011), 77

In the course of our investigations on Strychnos usambarensis leaves in order to isolate isostrychnopentamine, the main alkaloid responsible for the antiplasmodial activity of the plant, a new tertiary ... [more ▼]

In the course of our investigations on Strychnos usambarensis leaves in order to isolate isostrychnopentamine, the main alkaloid responsible for the antiplasmodial activity of the plant, a new tertiary indolic alkaloid has been isolated: 17-O-acetyl, 10-hydroxycorynantheol 1. Its structure was determined by means of spectroscopic and spectrometric methods such as UV, IR, CD, NMR and ESI-MS. 17-O-acetyl, 10-hydroxycorynantheol 1 is one of the most active monomeric indole alkaloid known to date showing an in vitro activity against Plasmodium falciparum close to 5 µM and a high selectivity. [less ▲]

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See detailIntroduction à la métabolomique
Frederich, Michel ULg

Conference (2011, May 18)

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See detail17-O-acetyl, 10-hydroxycorynantheol, a selective antiplasmodial alkaloid isolated from Strychnos usambarensis leaves
Cao, Martine ULg; Muganga, Raymond ULg; Tits, Monique ULg et al

Conference (2011, May 13)

In the course of our investigations on Strychnos usambarensis leaves in order to isolate isostrychnopentamine, the main alkaloid responsible for the antiplasmodial activity of the plant, a new tertiary ... [more ▼]

In the course of our investigations on Strychnos usambarensis leaves in order to isolate isostrychnopentamine, the main alkaloid responsible for the antiplasmodial activity of the plant, a new tertiary indolic alkaloid has been isolated: 17-O-acetyl, 10-hydroxycorynantheol 1. Its structure was determined by means of spectroscopic and spectrometric methods such as UV, IR, CD, NMR and ESI-MS. 17-O-acetyl, 10-hydroxycorynantheol 1 is one of the most active monomeric indole alkaloid known to date showing an in vitro activity against Plasmodium falciparum close to 5 µM and a high selectivity. [less ▲]

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See detailEspectroscopia aplicada
Ziemons, Eric ULg; Frederich, Michel ULg; Fillet, Marianne ULg et al

Scientific conference (2011, May)

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See detailPharmacognosie volume III
Frederich, Michel ULg; Tits, Monique ULg; Angenot, Luc ULg

Learning material (2011)

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See detailPharmacognosie volume II
Frederich, Michel ULg; Tits, Monique ULg; Angenot, Luc ULg

Learning material (2011)

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See detailAntiplasmodial, anti-inflammatory and cytotoxic activities of various plant extracts from the Mascarene Archipelago.
Jonville, Marie ULg; Kodja, H.; Strasberg, D. et al

in Journal of Ethnopharmacology (2011), 136

AIM OF THE STUDY: Antiplasmodial activity, inhibition of nitric oxide (NO) overproduction, and anti-proliferative activity were investigated in vitro to evaluate the bioactive potential of the traditional ... [more ▼]

AIM OF THE STUDY: Antiplasmodial activity, inhibition of nitric oxide (NO) overproduction, and anti-proliferative activity were investigated in vitro to evaluate the bioactive potential of the traditional pharmacopoeia of the Mascarene Archipelago, which is known for its biodiversity and for the richness of its endemic flora. MATERIALS AND METHODS: A total of 45 methanol (MeOH) and dichloromethane (DCM) extracts were prepared from 19 plant species collected on Reunion and Mauritius Islands. Ninety-six-well microplate assays were performed on chloroquine sensitive Plasmodium falciparum 3D7 strain, on LPS-stimulated Raw 264.7 murine macrophages and on A-549, DLD-1 and WS1 human cells. Activity was evaluated through spectrophotometric methods. RESULTS: Activity was attributed to plant extracts expressing IC(50)<50mug/ml for antiplasmodial response, IC(50)<100mug/ml for cytotoxicity, and IC(50)<130mug/ml for anti-inflammatory reaction. The majority of the extracts tested (69%) exhibited potency in at least one of these three types of activity. This is the first report describing promising antiplasmodial activity (IC(50)<15mug/ml) for Psiadia dentata DCM extract and Terminalia bentzoe MeOH bark extract. NO inhibition assay revealed seven interesting plants, described for the first time as anti-inflammatory: Aphloia theiformis, Buddleja salviifolia, Eupatorium riparium, Hiptage benghalensis, Psiadia arguta, Psiadia dentata, and Scutia commersonii. Finally, anti-proliferative activity was observed for two endemic species, Geniostoma borbonicum and Nuxia verticillata. CONCLUSION: Using the criterion of endemism as part of the criteria for traditional medicinal use raises the chances of finding original active principles. In our case, 86% of the endemic plants tested displayed pharmacological interest. [less ▲]

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See detailQuality control of Citri reticulatae pericarpium: Exploratory analysis and discrimination.
Tistaert, Christophe; Thierry, Line; Szandrach, Andrzej et al

in Analytica Chimica Acta (2011), 705(1-2), 111-22

Extracts of Citri reticulatae pericarpium (PCR) are commonly used in the Traditional Chinese Medicine. The quality control of PCR is currently performed by single marker analysis, which can hardly ... [more ▼]

Extracts of Citri reticulatae pericarpium (PCR) are commonly used in the Traditional Chinese Medicine. The quality control of PCR is currently performed by single marker analysis, which can hardly describe the complexity of such natural samples. In this study, a fingerprint methodology for PCR based on high-performance liquid chromatography (HPLC) was developed and validated. A total of 69 fingerprints of authenticated PCR samples, commercial PCR samples, mixed peel samples, and other Citrus peels were recorded. Exploratory data analysis allowed optimizing the extraction procedure and detecting mixed peel samples. Once the optimizations were performed and the method validated, discrimination between the authentic PCR samples and all other samples was performed by p-Discriminant Partial Least Squares. The established model was able to differentiate between classes with a high reliability for each sample. Furthermore, evaluation of the score and loading plots of the model indicated nobiletin, tangeretin, naringin and hesperidin as important markers for the quality control of PCR. [less ▲]

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See detailQuality Assessment of Polygonum cuspidatum and Polygonum multiflorum by 1H NMR Metabolite Fingerprinting and Profiling Analysis.
Frederich, Michel ULg; Wauters, Jean-Noël ULg; Tits, Monique ULg et al

in Planta Medica (2011), 77

The quality assessment and control of traditional Chinese medicines (TCM) nowadays receives a great deal of attention worldwide and particularly in Europe with its increasing local use. POLYGONUM ... [more ▼]

The quality assessment and control of traditional Chinese medicines (TCM) nowadays receives a great deal of attention worldwide and particularly in Europe with its increasing local use. POLYGONUM CUSPIDATUM Siebold & Zucc. and POLYGONUM MULTIFLORUM Thunb. are two members of the Polygonaceae family, which are widely used as Chinese medicinal plants. The aim of this study was to achieve an overview of the quality of P. CUSPIDATUM and P. MULTIFLORUM samples available on the Chinese market and to identify important metabolites for their discrimination, using (1)H NMR-based metabolomics. (1)H NMR and multivariate analysis techniques were applied to almost 60 plant samples collected in different places in China. Using (1)H NMR metabolomics, it was possible, without previous evaporation or separation steps, to obtain metabolic fingerprints to distinguish between the species. The important metabolites for discrimination were stilbene derivatives. Finally, a clear distinction between the two species was possible and the discriminant metabolites were identified. [less ▲]

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See detailApplication of a new optimization strategy for the separation of tertiary alkaloids extracted from Strychnos usambarensis leaves
Nistor, Iolanda ULg; Cao, Martine ULg; Debrus, Benjamin ULg et al

in Journal of Pharmaceutical & Biomedical Analysis (2011), 56

The HPLC separation of six alkaloids extracted from Strychnos usambarensis leaves has been developed and optimized by means of a powerful methodology for modelling chromatographic responses, based on ... [more ▼]

The HPLC separation of six alkaloids extracted from Strychnos usambarensis leaves has been developed and optimized by means of a powerful methodology for modelling chromatographic responses, based on three steps, i.e. design of experiments (DoE), independent component analysis (ICA) and design space (DS). This study was the first application of a new optimization strategy to a complex natural matrix. The compounds separated are the isomers isostrychnopentamine and strychnopentamine, 10-hydroxyusambarine and 11-hydroxyusambarine, also strychnophylline and strychnofoline. Three LC parameters have been optimized using a multifactorial design comprising 29 experiments that includes 2 center point replicates. The parameters were the percentage of organic modifiers used at the beginning of a gradient profile which consisted in different proportions of methanol (MeOH) and acetonitrile (MeCN), the gradient time to reach 70% of organic modifiers starting from the initial percentage and the percentage of MeCN found in the mobile phase. Subsequent to the experimental design application, predictive multilinear models were developed and used in order to provide optimal analytical conditions. The optimum assay conditions were: methanol/acetonitrile-sodium pentane sulfonate (pH 2.2; 7.5 mM) (33.4:66.6, v/v) at a mobile phase flow rate of 1mL/min during a 40.6 minutes gradient time. The initial organic phase contained 3.7% MeCN and 96.3% MeOH. The method showed good agreement between the experimental data and predictive value throughout the studied parameters space. Improvement of the analysis time and optimized separation for the compounds of interest was possible due to the original and powerful tools applied. Finally, this study permitted the acquisition of isomers profiles allowing the identification of the optimal collecting period of Strychnos usambarensis. [less ▲]

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See detailNew strategy to in vitro evaluation of antimalarial drugs demonstre advantage of Artemisia annua crude extract on antimalarial effect by its tools to cross intestinal barrier
Melilo de Magalhaes, Pedro; Schneider, Y. J.; Dupont, Isabelle et al

Poster (2010, October 03)

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