References of "Frederich, Michel"
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See detailA new ent-clerodane diterpenoid from Crassocephalum bauchiense Huch. (Asteraceae).
Tchinda, Alembert T.; Mouokeu, Simplice R.; Ngono, Rosalie A. N. et al

in Natural product research (2015), 29(21), 1990-1994

A phytochemical investigation of the whole plant of Crassocephalum bauchiense Huch. resulted in the isolation of a new clerodane diterpenoid, ent-2beta,18,19-trihydroxycleroda-3,13-dien-16,15-olide (1 ... [more ▼]

A phytochemical investigation of the whole plant of Crassocephalum bauchiense Huch. resulted in the isolation of a new clerodane diterpenoid, ent-2beta,18,19-trihydroxycleroda-3,13-dien-16,15-olide (1), together with two known flavonoids 3',5-dihydroxy-4',5',6,7,8-pentamethoxyflavone (2) and 4',5-dihydroxy-3',5',6,7,8-pentamethoxyflavone (3). The compounds were tested against the chloroquine-sensitive 3D7 strain of Plasmodium falciparum. Compound 2 showed weak activity (IC50 = 10.1 g/mL) whilst compounds 1 and 3 were inactive. The structures of the compounds were elucidated by using detailed spectral analyses, especially 1H and 13C NMR, 1H-1H COSY, NOESY, HMBC and HR-ESI-MS. [less ▲]

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See detailTerritoires périurbains : développement, enjeux et perspectives dans les pays du Sud. Une introduction générale
Halleux, Jean-Marie ULg; Courtejoie, Fabienne ULg; Dawance, Sophie ULg et al

in Bogaert, Jan; Halleux, Jean-Marie (Eds.) Territoires périurbains Développement, enjeux et perspectives dans les pays du Sud (2015)

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See detailSteroidal Glycosides from the Flowers of Allium leucanthum
Mskhiladze, Lasha; Chincharadze, David; Mshvildadze, Vakhtang et al

in Chemistry of Natural Compounds (2015), 51(5), 900-904

Furostanol and spirostanol glycosides 1 and 2 were isolated from the flowers of Allium leucanthum, a Caucasian endemic species that grows in Georgia. The structures were established on the base of ... [more ▼]

Furostanol and spirostanol glycosides 1 and 2 were isolated from the flowers of Allium leucanthum, a Caucasian endemic species that grows in Georgia. The structures were established on the base of chemical evidence and spectral analyses ( 1 H, 13 C NMR, 1 H– 1 H COSY, 1 H– 13 C COSY, HMBC, and HR-MS) data. Compound 1 (leucofuranoside A) was reported for the first time and was identified as 26-O-β-Dglucopyranosyl-(25R)-5α-furostane-3β,6β-diol-3-O-β-D-glucopyranosyl-(1→2)-O-β-D-xylopyranosyl-(1→3)-O-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside. Compound 2 was identified as (25R)-5α-spirostane-3β,6β-diol-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside and described for the first time in the genus Allium. [less ▲]

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See detailNetamines O-S, Five New Tricyclic Guanidine Alkaloids from the Madagascar Sponge Biemna laboutei, and Their Antimalarial Activities.
Gros, Emmanuelle; Martin, Marie-Therese; Sorres, Jonathan et al

in Chemistry & biodiversity (2015), 12(11), 1725-33

In our continuing program to isolate new compounds from the Madagascar sponge Biemna laboutei, five new tricyclic guanidine alkaloids, netamines O - S (1-5, resp.), have been identified together with the ... [more ▼]

In our continuing program to isolate new compounds from the Madagascar sponge Biemna laboutei, five new tricyclic guanidine alkaloids, netamines O - S (1-5, resp.), have been identified together with the known compounds netamine E (6) and mirabilin J (7). The structures of all new netamines were assigned on the basis of spectroscopic analyses. Their relative configurations were established by analysis of ROESY data and comparison with literature data. Netamines O, P, and Q, which were isolated in sufficient quantities, were tested for their cytotoxic activities against KB cells and their activities against the malaria parasite Plasmodium falciparum. Netamines O and Q were found to be moderately cytotoxic. Netamines O, P, and Q exhibited antiplasmodial activities with IC50 values of 16.99+/-4.12, 32.62+/-3.44, and 8.37+/-1.35 muM, respectively. [less ▲]

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See detailPROXIMATE ANALYSIS OF SEEDS FROM SOME FIELD BORDER FLOWERING STRIPS
Paul, Aman ULg; Frederich, Michel ULg; Uyttenbroeck, Roel ULg et al

in Scientific Bulletin. Series F. Biotechnologies (2015), XIX

Field border flowering strips are commonly grown throughout the world mainly to enhance biodiversity. However besides their basic function they can also yield numerous compounds which could be interesting ... [more ▼]

Field border flowering strips are commonly grown throughout the world mainly to enhance biodiversity. However besides their basic function they can also yield numerous compounds which could be interesting for wide range of industries such as food, pharmaceutical, etc. With the aim of valorization, proximate compositional analysis of seeds from some commonly grown flowering strips: Galium verum, Hypericum perforatum, Leontodon hispidus, Lotus corniculatus, Lythrum salicaria, Origanum vulgare and Trifolium pratense was realized. The protein content of residue left after the lipid extraction was also determined for exploring possibilities of its utilization as a protein source. Results suggest that seeds from some of these plants can be a potential source to render food compounds. [less ▲]

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See detailSemisynthesis and in Vitro Photodynamic Activity Evaluations of Halogenated and Glycosylated Derivatives of Pheophorbide a
Cieckiewicz, Ewa ULg; Mathieu, Véronique; Angenot, Luc ULg et al

in European Journal of Organic Chemistry (2015), 2015(27), 6061--6074

The present work focuses on the semisynthesis of halogenated and glycosylated derivatives of pheophorbide a (Pha). Because of the low reaction yields enocuntered en route to halogenated derivatives, we ... [more ▼]

The present work focuses on the semisynthesis of halogenated and glycosylated derivatives of pheophorbide a (Pha). Because of the low reaction yields enocuntered en route to halogenated derivatives, we then focused only on the semisynthesis of glycosylated derivatives of Pha with the aim at enhancing the Pha specificity for cancer cells by introducing β-galactose moieties expected to bind gal-1. We applied LC-SPE-NMR/MS, to facilitate the direct identification of glycosylated derivatives. The transposition of these analytical methods to a preparative scale facilitated the isolation of glycosylated compounds in quantities sufficient to evaluate in vitro photodynamic efficacies. The in vitro growth inhibitory activity of semisynthesized compounds was then evaluated using the MTT colorimetric assay in the presence and absence of light. However, this pharmacological evaluation method seems to be unable to efficiently yield information about carbohydrate effects in relation to possible compound specificities for gal-1 overexpressed by B16F10 cancer cells. [less ▲]

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See detailStructure-activity relationship of hybrids of Cinchona alkaloids and bile acids with in vitro antiplasmodial and antitrypanosomal activities.
Leverrier, Aurelie; Bero, Joanne; Cabrera, Julian et al

in European journal of medicinal chemistry (2015), 100

In this work, a series of hybrid compounds were tested as antiparasitic substances. These hybrids were prepared from bile acids and a series of antiparasitic Cinchona alkaloids by the formation of a ... [more ▼]

In this work, a series of hybrid compounds were tested as antiparasitic substances. These hybrids were prepared from bile acids and a series of antiparasitic Cinchona alkaloids by the formation of a covalent C-C bond via a decarboxylative Barton-Zard reaction between the two entities. The bile acids showed only weak antiparasitic properties, but all the hybrids exhibited high in vitro activities (IC50: 0.48-5.39 muM) against Trypanosoma brucei. These hybrids were more active than their respective parent alkaloids (up to a 135 fold increase in activity), and displayed good selectivity indices. Aditionally, all these compounds inhibited the in vitro growth of a chloroquine-sensitive strain of Plasmodium falciparum (3D7: IC50: 36.1 nM to 8.72 muM), and the most active hybrids had IC50s comparable to that of artemisinin (IC50: 36 nM). Some structure-activity relationships among the group of 48 hybrids are discussed. The increase in antiparasitic activity may be explained by an improvement in bioavailability, since the more lipophilic derivatives showed the lowest IC50s. [less ▲]

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See detailNuclear magnetic resonance: a key metabolomics platform in the drug discovery process.
Leenders, Justine ULg; Frederich, Michel ULg; De Tullio, Pascal ULg

in Drug discovery today. Technologies (2015), 13

Metabolomics is an innovative tool that is now emerging in the drug discovery process. Indeed, its ability to follow the dynamic perturbations in the metabolome resulting from pathologies but also from ... [more ▼]

Metabolomics is an innovative tool that is now emerging in the drug discovery process. Indeed, its ability to follow the dynamic perturbations in the metabolome resulting from pathologies but also from drug treatment and or/toxicity is of value for the development of new therapeutic approaches. Nuclear magnetic resonance (NMR) spectroscopy, which is an important analytical technique for several steps of the lead discovery, validation and optimization processes, has been described, together with mass spectrometry (MS) as one of the major platform that could be used for metabolomics studies. This review highlights why NMR could be considered a key tool for the application of metabolomics in drug discovery. [less ▲]

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See detailAntrocarines A-F, antiplasmodial ergostane steroids from the stem bark of Antrocaryon klaineanum.
Douanla, Pascal D.; Tabopda, Turibio Kuiate; Tchinda, Alembert T. et al

in Phytochemistry (2015), 117

During a study on the chemistry and biological activity of Antrocaryon klaineanum Pierre, six new sterols including 4,24(28)-ergostadiene-6alpha,7alpha-diol (1), 6alpha-methoxy-4,24(28)-ergostadiene ... [more ▼]

During a study on the chemistry and biological activity of Antrocaryon klaineanum Pierre, six new sterols including 4,24(28)-ergostadiene-6alpha,7alpha-diol (1), 6alpha-methoxy-4,24(28)-ergostadiene-7alpha,20S-diol (2), 6alpha-methoxy-4,24(28)-ergostadien-7alpha-ol (3), 20S-hydroxy-24(28)-ergosten-3-one (4), 7alpha-hydroxy-4,24(28)-ergostadien-3-one (5), and 24(28)-ergostene-3beta,6alpha-diol (6) were characterized by physical and spectroscopic means. The known steroids 7 and 8 were also isolated. The crude extract and the isolated compounds were evaluated for their ability to inhibit the 3D7 strain of Plasmodium falciparum. Compounds 2, 3, and 8 showed potent activity while that of the crude extract was moderate. [less ▲]

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See detailCarbon Multiplicity Editing in Long-Range Heteronuclear Correlation NMR Experiments: A Valuable Tool for the Structure Elucidation of Natural Products.
Sauri, Josep; Frederich, Michel ULg; Tchinda, Alembert T. et al

in Journal of natural products (2015), 78(9), 2236-41

A recently developed NMR method to simultaneously obtain both long-range heteronuclear correlations and carbon multiplicity information in a single experiment, ME-selHSQMBC, is demonstrated as a ... [more ▼]

A recently developed NMR method to simultaneously obtain both long-range heteronuclear correlations and carbon multiplicity information in a single experiment, ME-selHSQMBC, is demonstrated as a potentially useful technique for chemical shift assignment and structure elucidation of natural products presenting complicated NMR spectra. Carbon multiplicities, even for C/CH2 and odd for CH/CH3 resonances, can be distinguished directly from the relative positive/negative phase of cross-peaks. In addition, connectivity networks can be further extended by incorporating a TOCSY propagation step. Staurosporine (1) and sungucine (2) are utilized as model compounds to demonstrate these techniques. [less ▲]

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See detailIdentification of Cytotoxic and Antioxidant Compounds from Allium gramineum Flowers
Mskhiladze, Lasha; Chincharadze, David; Tits, Monique ULg et al

in International Journal of Pharmaceutical Sciences and Drug Research (2015), 7

The present study evaluates the in vitro anticancer, antiplasmodial and antioxidant activity of the ethanolic crude extract from the flowers of Allium gramineum growing in Georgia and of one flavonol and ... [more ▼]

The present study evaluates the in vitro anticancer, antiplasmodial and antioxidant activity of the ethanolic crude extract from the flowers of Allium gramineum growing in Georgia and of one flavonol and two steroidal glycosides which were isolated from this plant. The flowers were extracted with ethanol and this total extract was subjected to successive bioguided fractionations to provide glycosides 1-3. Their structures were elucidated on the basis of NMR and ESI-MS spectrometric data in comparison with the existing literature and have been identified as: isorhamnetin-3-O-β-D-glucopyranoside (1), diosgenin-3-O-α-rhamnopyranosyl-(1→2)-β-D-glucopyranoside (Prosapogenin A of dioscin) (2), diosgenin-3-O-α-rhamnopyranosyl-(1→2)-[β-D-glucopyranosyl-(1→4)-]-β-D-glucopyranoside (Deltonine) (3). The ethanolic extract has been shown to strongly inhibit the growth of breast adenocarcinoma cell lines, with an IC50 of 4.5 ± 0.7μg/mL for MDAMB-231 and 4.8 ± 0.9μg/mL for MCF-7 cells. The cytotoxic activity was related to 2 and 3 which exhibited potent cytotoxicity, with an IC50 of ± 3μM. Concerning antiplasmodial activities, only weak activities were observed using the ethanolic extract and the two saponins. The flavonoid was almost inactive. Finally, the radical-scavenging activity of the ethanolic extract was tested in presence of ABTS·+ solution. A decrease of the absorbance intensity was observed, with an IC50 value of 22.1 ± 0.6μg/mLwhile trolox, used as Standard drug, showed a pronounced activity (IC50 = 12.7±0.5μM). The glycoside 1 showed the lowest IC50 value of 20.1 ± 0.8μM while both 2 and 3 exhibited very weak radical scavenging activity. [less ▲]

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See detailThe emergence of metabolomics as a key discipline in the drug discovery process
Fillet, Marianne ULg; Frederich, Michel ULg

in Drug Discovery Today: Technologies (2015)

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See detailLes nouveaux outils de diagnostic et de pronostic de la myopathie atypique
Habyarimana, Jean ULg; BOEMER, François ULg; Amory, Hélène ULg et al

in Proceeding de la 41ème Journée de la Recherche équine (2015)

In equines, ingestion of hypoglycin A, a toxin produced in the seeds (samaras) of sycamore maple (Acer pseudoplatanus) tree alters the energetic metabolism of muscle cells and results in atypical myopathy ... [more ▼]

In equines, ingestion of hypoglycin A, a toxin produced in the seeds (samaras) of sycamore maple (Acer pseudoplatanus) tree alters the energetic metabolism of muscle cells and results in atypical myopathy (AM). This alterations leads to a characteristic biochemical profile of acylcarnitines (AC) that enables to confirm the diagnosis of AM. This study aims at validating a methodology for the dosage of hypoglycin A in vegetal extracts but also in blood. In addition, the biochemical profile in AC has been determined in AM cases (5 survivors and 13 deceased) and in 5 horses suffering from exercise-induced myopathy. The AC profiles of these horses have been compared to the one of healthy horses (n = 35). This study showed that hypoglycin A was present in seeds and spring seedlings of sycamore and also in blood of AM cases horses. In addition, the establishment of AC profile contributes to the diagnostic and helps to assess the prognosis of AM cases. [less ▲]

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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

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See detailINVESTIGATION OF TWO IMPROVED TRADITIONAL MEDICINES: DEVELOPMENT AND VALIDATION OF A LC-UV METHOD FOR THE DOSAGE OF A TRACER COMPOUND
Tshisekedi Tshibangu, Pascal; Kalenda Dibungi, Pascal; Rozet, Eric ULg et al

Poster (2014, June)

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See detailMealworms: Alternate Source of Lipids
Danthine, Sabine ULg; Blecker, Christophe ULg; Paul, Aman ULg et al

Scientific conference (2014, May 16)

The aim of present study was to determine the physicochemical properties of the oil obtained from Tenebrio molitor larvae (mealworms) and explore its potential as edible oil. Five batches of Tenebrio ... [more ▼]

The aim of present study was to determine the physicochemical properties of the oil obtained from Tenebrio molitor larvae (mealworms) and explore its potential as edible oil. Five batches of Tenebrio molitor larvae were investigated for their lipid content and physiochemical properties. Three batches were reared in lab (3 different productions) and two were purchased from a local supplier. The lipids were extracted using a cold extraction technique employing 2:1 ratio chloroform/methanol as solvent. The fatty acid profile was determined using gas chromatography and triacylglycerol profile using HPLC. The thermal properties of the lipid extracts were also analyzed using differential scanning calorimetry. All the samples contained high amount of unsaturated fatty acids. The chemical composition and the thermal properties of the samples varied with the source. With this quantity and quality of lipid content, mealworms offer potential as an important source of edible lipids. [less ▲]

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See detailBelgian Grasshoppers: A Nutritious Food Source
Paul, Aman ULg; Frederich, Michel ULg; Blecker, Christophe ULg et al

Poster (2014, May 14)

Rapid urbanization and rising economies are creating shifts in the composition of global food demand, so it is necessary to explore new sources of food with better nutritional profile. Among the ... [more ▼]

Rapid urbanization and rising economies are creating shifts in the composition of global food demand, so it is necessary to explore new sources of food with better nutritional profile. Among the alternative food that exists are the grasshoppers, about 80 species of which are consumed worldwide. Grasshoppers are not only rich source of proteins and lipids but also some important minor component like vitamins and minerals. Edible species of grasshopper in Belgium were identified and attempts were made for the lab rearing of meadow grasshopper (Chorthippus parallelus). The lipids as well as protein contents of meadow grasshopper (Chorthippus parallelus) & long winged conehead (Conocephalus discolor) were investigated. The fatty acid compositions of these two species were determined by gas chromatography. Some of the physicochemical properties of the lipids extracted were also analyzed. These two grasshopper species could be really nutritious source of food. [less ▲]

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See detailLocusts and Grasshoppers: Future Foods?
Paul, Aman ULg; Frederich, Michel ULg; Uyttenbroeck, Roel ULg et al

Scientific conference (2014, May 08)

Consuming locusts and grasshoppers as food is not a new concept, because some people have been doing it for a long time and there are many references in the religious literature to support this. About 80 ... [more ▼]

Consuming locusts and grasshoppers as food is not a new concept, because some people have been doing it for a long time and there are many references in the religious literature to support this. About 80 locust and grasshopper species are consumed worldwide, and the large majority of grasshopper species are edible. From the nutritional point of view they are an excellent source of proteins, lipids and other minor components like vitamins and minerals. They are an excellent source of amino acids and their lipids contain a large majority of unsaturated fatty acids. Environmentalists have supported human consumption of grasshoppers owing to the facts that they usually appear as pests. Using them as food could help reduce their population and result in limited application of harmful pesticides. Their production usually generates lesser amount of greenhouse gases & ammonia; a lower amount of water is required for their production in comparison to conventional proteins sources. Some species of grasshoppers usually feed on dead organic matter, this reduces the environmental load. In the developing world, catching of grasshoppers and selling them for human consumption has played a key role in improving the livelihood of women and underprivileged children. Eating grasshopper and locust is not a very common practice in temperate areas. However it is a very common practice in the tropical areas of world because of the higher density, bigger size of the insect and yearlong availability in such areas. To encourage their consumption in temperate areas, it is now necessary to perform accurate research regarding food safety (minor components, toxicity, allergens,…) but also to develop value added products to make it easier for people to adapt with entomophagy. Furthermore we have to develop methods for commercial production and organize awareness campaigns to explain about the nutritional and other benefits related to locust & grasshopper consumption as food to people. [less ▲]

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See detailChemical analyses of the seeds from Prunella vulgaris: A chemotaxonomic approach
Paul, Aman ULg; Frederich, Michel ULg; Cieckiewicz, Ewa ULg et al

Poster (2014, April)

Common self-heal (Prunella vulgaris) plants are traditionally sown along the border of crops to enhance the biodiversity. Besides enhancing the biodiversity, they can also be a source of interesting ... [more ▼]

Common self-heal (Prunella vulgaris) plants are traditionally sown along the border of crops to enhance the biodiversity. Besides enhancing the biodiversity, they can also be a source of interesting compounds which could be important for food, pharmaceutical and cosmetic industries. The seeds of Common self-heal were investigated for proteins, fatty acid compositions and polyphenolic compounds. The protein content was analyzed according to Dumas method, the extraction of oil was done using a cold extraction technique employing 2:1 chloroform/methanol as solvent, the fatty acid composition was determined using the gas chromatography and the amount of polyphenolic compounds were estimated using the method as described in European Pharmacopoeia, 8th edition. Common self-heal seeds can be of great commercial importance. [less ▲]

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