References of "Frederich, Michel"
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See detailBiologically active bisbenzylisoquinoline alkaloids from the root bark of Epinetrum villosum
Otshudi, A. L.; Apers, S.; Pieters, L. et al

in Journal of Ethnopharmacology (2005), 102(1), 89-94

Methanol and water extracts of the root of Epinetrum villosum (Exell) Troupin (Menispermaceae) were found to exhibit antimicrobial and antiplasmodial activities. Investigation of the active methanol ... [more ▼]

Methanol and water extracts of the root of Epinetrum villosum (Exell) Troupin (Menispermaceae) were found to exhibit antimicrobial and antiplasmodial activities. Investigation of the active methanol fraction led to the isolation of four bisbenzylisoquinoline alkaloids, i.e., cycleanine, cycleanine N-oxide, isochondodendrine and cocsoline. Structures were established by spectroscopic methods. Cocsoline displayed antibacterial and antifungal activities (MIC values of 1000-15.62 and 31.25 mu g/ml, respectively). Isochondodendrine was found to have the most potent antiplasmodial activity (IC50 = 0- 10 mu g/ml), whereas the IC50 on HCT-116 human colon carcinoma cells was 17.5 mu g/ml (selectivity index 175). Cycleanine acted against HIV-2 (EC50 = 1.83 mu g/ml) but was at least 10-fold less active against HIV-1. Cycleanine N-oxide showed no activity towards all tested microorganisms. (C) 2005 Elsevier Ireland Ltd. All rights reserved. [less ▲]

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See detailIn vitro screening of some Strychnos species for antiplasmodial activity
Philippe, Geneviève ULg; Angenot, Luc ULg; De Mol, Patrick ULg et al

in Journal of Ethnopharmacology (2005), 97(3), 535-539

The antiplasmodial activity of crude extracts of 19 species of Strychnos (Loganiaceae) was assessed in vitro against a chloroquine-susceptible strain of Plasmodium falciparum. For each species, ethyl ... [more ▼]

The antiplasmodial activity of crude extracts of 19 species of Strychnos (Loganiaceae) was assessed in vitro against a chloroquine-susceptible strain of Plasmodium falciparum. For each species, ethyl acetate (EtOAc) extracts were analysed and, for the most active species, methanolic (MeOH) extracts were also tested. Among them, Strychnos variabilis De Wild. seemed to be very promising (inhibitory concentration 50% (IC50) < 5 microg/ml) whereas two other species, Strychnos gossweileri Exell and Strychnos mellodora S. Moore, could be interesting (IC50 < 15 microg/ml) in further antimalarial studies. [less ▲]

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See detailAbout the toxicity of some Strychnos species and their alkaloids
Philippe, Geneviève ULg; Angenot, Luc ULg; Tits, Monique ULg et al

in Toxicon (2004), 44(4), 405-416

Poisons are widespread in plants and animals and humankind has often tried to turn them to its own advantage. Owing to their poisonous properties, some species of Strychnos genus have been employed mainly ... [more ▼]

Poisons are widespread in plants and animals and humankind has often tried to turn them to its own advantage. Owing to their poisonous properties, some species of Strychnos genus have been employed mainly in hunting and fishing, as an adjunct to weapons used not only in the search of food and clothes, but also for preventing depredation by wild animals. They have been employed for martial and criminal purposes and also as a means of determining guilt or innocence. By their nature, poisons such as strychnine and curate affect the functioning of the victim's body; this also means that they have been, and are, an important source of pharmacological tools and medicines all over the world. With such potentially dangerous substances, care in medication is essential to avoid complications by overdose. All these points are approached in the present review. (C) 2004 Elsevier Ltd. All rights reserved. [less ▲]

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See detailMetabolomic analysis of Strychnos nux-vomica, Strychnos icaja and Strychnos ignatii extracts by H-1 nuclear magnetic resonance spectrometry and multivariate analysis techniques
Frederich, Michel ULg; Choi, Young Hae; Angenot, Luc ULg et al

in Phytochemistry (2004), 65(13), 1993-2001

H-1 Nuclear magnetic resonance spectrometry and multivariate analysis techniques were applied for the metabolic profiling of three Strychnos species: Strychnos nux-vomica (seeds, stem bark, root bark ... [more ▼]

H-1 Nuclear magnetic resonance spectrometry and multivariate analysis techniques were applied for the metabolic profiling of three Strychnos species: Strychnos nux-vomica (seeds, stem bark, root bark), Strychnos ignatii (seeds), and Strychnos icaja (leaves, stem bark, root bark, collar bark). The principal component analysis (PCA) of the H-1 NMR spectra showed a clear discrimination between all samples, using the three first components. The key compounds responsible for the discrimination were brucine, loganin, fatty acids.. and Strychnos icaja alkaloids such as icajine and sungucine. The method was then applied to the classification of several "false angostura" samples. These samples were, as expected, identified as S. nux-vomica by PCA, but could not be clearly discriminated as root bark or stem bark samples after further statistical analysis. (C) 2004 Published by Elsevier Ltd. [less ▲]

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See detailIn vitro and in vivo antimalarial properties of isostrychnopentamine, an indolomonoterpenic alkaloid from Strychnos usambarensis
Frederich, Michel ULg; Tits, Monique ULg; Goffin, Eric ULg et al

in Planta Medica (2004), 70(6), 520-525

Isostrychnopentamine (ISP) is an asymmetric indolomonoterpenic alkaloid isolated from the leaves of Strychnos usambarensis. The in vitro antiplasmodial activities against five Plasmodium falciparum cell ... [more ▼]

Isostrychnopentamine (ISP) is an asymmetric indolomonoterpenic alkaloid isolated from the leaves of Strychnos usambarensis. The in vitro antiplasmodial activities against five Plasmodium falciparum cell lines were evaluated: ISP possessed an in vitro IC (50) near 0.1 microM against all P. falciparum cell lines tested (chloroquine-resistant and chloroquine-sensitive lines) and showed antiplasmodial selectivity compared to cytotoxicity on human cell lines. The stage-dependent susceptibility to a short exposure of ISP was then investigated. The ring stage was shown to be the most sensitive one, but all stages were affected by ISP treatment. By means of fluorescence microscopy, it was shown that ISP was not accumulated inside the food vacuole of the parasite. Finally, the in vivo antimalarial activities against the P. berghei NK173 and P. vinckei petteri murine strains were determined. The ED (50) in vivo was about 30 mg/kg/day by the intraperitoneal route (after 4 days treatment). [less ▲]

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See detailLC/MS/NMR analysis of isomeric divanilloylquinic acids from the root bark of Fagara zanthoxyloides Lam
Ouattara, Badiore; Angenot, Luc ULg; Guissou, Pierre et al

in Phytochemistry (2004), 65(8), 1145-1151

Gradient HPLC coupled to DAD/UV, MS/MS and NMR has been applied to the rapid structure determination of three new isomeric divanilloylquinic acids from Fagara zanthoxyloides collected in Burkina Faso: 3,4 ... [more ▼]

Gradient HPLC coupled to DAD/UV, MS/MS and NMR has been applied to the rapid structure determination of three new isomeric divanilloylquinic acids from Fagara zanthoxyloides collected in Burkina Faso: 3,4-O-divanilloylquinic acid, 3,5-O-divanilloylquinic acid and 4,5-O-divanilloylquinic acid. Furthermore these new compounds named burkinabins A-C could play a useful role in sickle cell disease, as the active agents of Fagara zanthoxyloides are said to be unidentified aromatic compounds with carboxylic acid grouping (Adesanya, S.A., Sofowora, A., 1983. Biological standardisation of Zanthoxylum roots for antisickling activity. Planta Med. 48, 27-33). (C) 2004 Elsevier Ltd. All rights reserved. [less ▲]

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See detailChrysopentamine, an antiplasmodial anhydronium base from Strychnos usambarensis leaves
Frederich, Michel ULg; Cristino, Assunção; Choi, Young Hae et al

in Planta Medica (2004), 70(1), 72-76

A new derivative of strychnopentamine was isolated from the leaves of Strychnos usambarensis. This compound, named chrysopentamine, was identified by detailed spectroscopic methods (UV, IR, HR-ESI-MS, 1D ... [more ▼]

A new derivative of strychnopentamine was isolated from the leaves of Strychnos usambarensis. This compound, named chrysopentamine, was identified by detailed spectroscopic methods (UV, IR, HR-ESI-MS, 1D and 2D NMR). Chrysopentamine presented an original hydroxy substitution on C-14 and an aromatization of the ring D of strychnopentamine leading to anhydronium base proper-ties and exhibited strong antiplasmodial properties (IC50 less than 1 muM). [less ▲]

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See detailNMR assignments of the major Cannabinoids and cannabiflavonoids isolated from flowers of Cannabis sativa
Choi, Y. H.; Hazekamp, A.; Peltenburg-Looman, A. M. G. et al

in Phytochemical Analysis (2004), 15(6, NOV-DEC), 345-354

The complete H-1- and C-13-NMR assignments of the major Cannabis constituents, Delta(9)-tetrahydrocannabinol, tetrahydrocannabinolic acid, A-tetrahydrocannabinol, cannabigerol, cannabinol, cannabidiol ... [more ▼]

The complete H-1- and C-13-NMR assignments of the major Cannabis constituents, Delta(9)-tetrahydrocannabinol, tetrahydrocannabinolic acid, A-tetrahydrocannabinol, cannabigerol, cannabinol, cannabidiol, cannabidiolic acid, cannflavin A and cannflavin B have been determined on the basis of one- and two-dimensional NMR spectra including H-1- and (13)-NMR, H-1-H-1-COSY, HMQC and HMBC. The substitution of carboxylic acid on the cannabinoid nucleus (as in tetrahydrocannabinolic acid and cannabidiolic acid) has a large effect on the chemical shift of H-1" of the C5 side chain and 2'-OH. It was also observed that carboxylic acid substitution reduces intermolecular hydrogen bonding resulting in a sharpening of the H-5' signal in cannabinolic acid in deuterated chloroform. The additional aromaticity of cannabinol causes the two angular methyl groups (H-8 and H-9) to show identical H-1-NMR shifts, which indicates that the two aromatic rings are in one plane in contrast to the other cannabinoids. For the cannabiflavonoids, the unambiguous assignments of C-3' and C-4' of cannflavin A and B were determined by HMBC spectra. Copyright (C) 2004 John Wiley Sons, Ltd. [less ▲]

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See detailAlkaloid accumulation in Catharanthus roseus cell suspension cultures fed with stemmadenine
El-Sayed, M.; Choi, Y. H.; Frederich, Michel ULg et al

in Biotechnology Letters (2004), 26(10), 793-798

Feeding stemmadenine to Catharanthus roseus cell suspension culture resulted in the accumulation of catharanthine, tabersonine and condylocarpine. Condylocarpine is not an intermediate in the pathway to ... [more ▼]

Feeding stemmadenine to Catharanthus roseus cell suspension culture resulted in the accumulation of catharanthine, tabersonine and condylocarpine. Condylocarpine is not an intermediate in the pathway to catharanthine or tabersonine when it is fed to the cultures. The results support the hypothesis that stemmadenine is an intermediate in the pathway to catharanthine and tabersonine. [less ▲]

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See detailFirst and second generations of COX-2 selective inhibitors
De leval, X.; Julémont, F.; Benoit, V. et al

in Mini Reviews in Medicinal Chemistry (2004), 4

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See detailNew developments on thromboxane and prostacyclin modulators. Part I: thromboxane modulators
Dogné, Jean-Michel ULg; De leval, X.; Hanson, Julien ULg et al

in Current Medicinal Chemistry (2004), 11

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See detailQuantitative analysis of strychnine and brucine in Strychnos nux-vomica using H-1-NMR
Frederich, Michel ULg; Choi, Y. H.; Verpoorte, R.

in Planta Medica (2003), 69(12), 1169-1171

A quantitative analysis using H-1-NMR (Q-NMR) has been developed for the determination of strychnine and brucine in Strychnos nux-vomica seeds and stems. The advantages of the method are that no reference ... [more ▼]

A quantitative analysis using H-1-NMR (Q-NMR) has been developed for the determination of strychnine and brucine in Strychnos nux-vomica seeds and stems. The advantages of the method are that no reference alkaloids are needed for calibration curves, the quantification could be directly realized on a crude extract, strychnine and brucine could easily be distinguished, an overall profile of the preparation (including non alkaloid compounds) could be directly obtained, and a very significant time-gain could be achieved, in comparison to conventional HPLC methods, for instance. [less ▲]

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See detailQuantification of tagitinin C in Tithonia diversifolia by reversed-phase high-performance liquid chromatography.
Goffin, Eric ULg; da Cunha, Antonio Proenca; Ziemons, Eric ULg et al

in Phytochemical Analysis (2003), 14(6), 378-80

A simple, rapid and reliable reversed-phase high-performance liquid chromatographic method for the determination of tagitinin C, an anti-plasmodial sesquiterpene lactone isolated from the aerial parts of ... [more ▼]

A simple, rapid and reliable reversed-phase high-performance liquid chromatographic method for the determination of tagitinin C, an anti-plasmodial sesquiterpene lactone isolated from the aerial parts of Tithonia diversifolia, has been developed. The assay has been used to quantify tagitinin C in various extracts of the aerial parts of T. diversifolia. [less ▲]

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See detailAntiplasmodial and cytotoxic alkaloids from Strychnos species
Frederich, Michel ULg

Conference (2003, March 14)

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See detailIsostrychnopentamine, an indolomonoterpenic alkaloid from Strychnos usambarensis, induces cell cycle arrest and apoptosis in human colon cancer cells
Frederich, Michel ULg; Bentires-Alj, M.; Tits, Monique ULg et al

in Journal of Pharmacology and Experimental Therapeutics (2003), 304(3), 1103-1110

Isostrychnopentamine (ISP) is an indolomonoterpenic alkaloid that is present in the leaves of Strychnos usambarensis, a well known African shrub or little tree. The roots contain quaternary alkaloids ... [more ▼]

Isostrychnopentamine (ISP) is an indolomonoterpenic alkaloid that is present in the leaves of Strychnos usambarensis, a well known African shrub or little tree. The roots contain quaternary alkaloids, which are used to make a curare-like arrow poison. However, tertiary alkaloids isolated from the same plant possess cytotoxic activities against mammalian cells and protozoa. The effect of ISP has been investigated on the growth and viability of HCT-116 colon cancer cells during their exponentially growing phase. ISP induced apoptotic cell death as shown by the translocation of phosphatidylserine from the inner layer to the outer layer of the plasma membrane, chromatin condensation, DNA fragmentation, and caspase-3 and -9 activation. ISP provoked also cell cycle arrest in the G(2)-M phase. We also showed that the expression of p53 was not modified in ISP-treated cells, but that p21 was induced in a p53-independent manner. Finally, we demonstrated that ISP did not affect the catalytic activity of human topoisomerases I and II. In conclusion, ISP, which promotes cell death by a p53-independent apoptotic pathway, could be an interesting lead for cancer chemotherapy. [less ▲]

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See detailApoptosis induction in human cancer cells by sungucine from Strychnos icaja root
Frederich, Michel ULg; Bentires-Ali, M.; Tits, Monique ULg et al

in Naunyn-Schmiedeberg's Archives of Pharmacology (2003), 367(3), 260-265

Sungucine (SG) and isosungucine (ISG) are bisindole alkaloids characterized by a 5'-23 link between the two parts of the compounds, which are till now specific to Strychnos icaja. In this work, SG and ISG ... [more ▼]

Sungucine (SG) and isosungucine (ISG) are bisindole alkaloids characterized by a 5'-23 link between the two parts of the compounds, which are till now specific to Strychnos icaja. In this work, SG and ISG were submitted to the NCI's in vitro 60 human tumor cell line screen, where SG showed interesting selectivity (6X) against the tested leukemia cell lines. In HL60-treated cells, apoptosis was demonstrated by observation of apoptotic bodies formation, and phosphatidylserine exposition at cell surface. In HeLa-treated cells, the analysis of cellular cycle by flow cytometry showed G1 accumulation and a small sub-G1 peak that could be related to DNA fragmentation characteristic of apoptosis. The eventual role of p53 was analyzed using wild-type HCT-116 colon cancer cells. Nevertheless, p53 and Bax expression were not modified in SG-treated cells. The cleavage of PARP by caspase-3 protease proved that apoptosis was also induced in this line. These results demonstrate that SG induces apoptosis, but also necrosis, in human cancer cell lines. [less ▲]

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See detailIndolomonoterpenic alkaloids from Strychnos icaja roots
Philippe, Geneviève ULg; De Mol, Patrick ULg; Zeches-Hanrot, M. et al

in Phytochemistry (2003), 62(4), 623-629

In the course of our search for new antiplasmodial alkaloids from Strychnos icaja, we have isolated five alkaloids: three monomers, protostrychnine and genostrychnine, previously described in Strychnos ... [more ▼]

In the course of our search for new antiplasmodial alkaloids from Strychnos icaja, we have isolated five alkaloids: three monomers, protostrychnine and genostrychnine, previously described in Strychnos nux-vomica, pseudostrychnine, already found in the leaves of the plant, a new bisindolic alkaloid, named strychnogucine C, and the first naturally occurring trimeric indolomonoterpenic alkaloid: strychnohexamine. This latter trimeric alkaloid presented an antiplasmodial activity against the FCA Plasmodium falciparum line near I muM. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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