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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 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 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 detailAntioxidant and Antiradical Activities of Manihot esculenta Crantz (Euphorbiaceae) Leaves and Other Selected Tropical Green Vegetables Investigated on Lipoperoxidation and Phorbol-12-myristate-13-acetate (PMA) Activated Monocytes
Tsumbu, César Ndele ULg; Deby-Dupont, Ginette; Tits, Monique ULg et al

in Nutrients (2011), 3(9), 818-838

Abelmoschus esculentus (Malvaceae), Hibiscus acetosella (Malvaceae), Manihot esculenta Crantz (Euphorbiaceae) and Pteridium aquilinum (Dennstaedtiaceae) leaves are currently consumed as vegetables by ... [more ▼]

Abelmoschus esculentus (Malvaceae), Hibiscus acetosella (Malvaceae), Manihot esculenta Crantz (Euphorbiaceae) and Pteridium aquilinum (Dennstaedtiaceae) leaves are currently consumed as vegetables by migrants from sub-Saharan Africa living in Western Europe and by the people in the origin countries, where these plants are also used in the folk medicine. Manihot leaves are also eaten in Latin America and some Asian countries. This work investigated the capacity of aqueous extracts prepared from those vegetables to inhibit the peroxidation of a linoleic acid emulsion. Short chain, volatile C-compounds as markers of advanced lipid peroxidation were measured by gas chromatography by following the ethylene production. The generation of lipid hydroperoxides, was monitored by spectroscopy using N-N′-dimethyl-p-phenylene-diamine (DMPD). The formation of intermediate peroxyl, and other free radicals, at the initiation of the lipid peroxidation was investigated by electron spin resonance, using α-(4-pyridyl-1-oxide)-N-tert-butylnitrone as spin trap agent. The ability of the extracts to decrease the cellular production of reactive oxygen species (ROS) in “inflammation like” conditions was studied by fluorescence technique using 2′,7′-dichlorofluorescine-diacetate as fluorogenic probe, in a cell model of human monocytes (HL-60 cells) activated with phorbol ester. Overall the extracts displayed efficient concentration-dependent inhibitory effects. Their total polyphenol and flavonoid content was determined by classic colorimetric methods. An HPLC-UV/DAD analysis has clearly identified the presence of some polyphenolic compounds, which explains at least partially the inhibitions observed in our models. The role of these plants in the folk medicine by sub-Saharan peoples as well as in the prevention of oxidative stress and ROS related diseases requires further consideration. [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 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 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 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 detailLC-SPE-NMR-MS analysis of Strychnos usambarensis fruits from Rwanda
Cao, Martine ULg; Tits, Monique ULg; Muganga, Raymond et al

in Planta Medica (2010, September), 76(12), 1241-1242

Detailed reference viewed: 64 (19 ULg)
See detailPharmacognosie volume I
Frederich, Michel ULg; Tits, Monique ULg; Angenot, Luc ULg

Learning material (2010)

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See detailAntioxidant activity of Passiflora edulis and Passiflora alata fruits
Yariwake, J.; Zeraik, M.; Serteyn, Didier ULg et al

in Planta Medica (2010, September), 76(12), 1274-1275

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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

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See detailAnti-inflammatory potency of the traditionally used antimalarial plant Fagraea fragrans
Jonville, Marie ULg; Baghdikian, Béatrice; Ollivier, Evelyne et al

in Planta Medica (2010, September), 76(12), 1171

Detailed reference viewed: 43 (4 ULg)