References of "Angenot, Luc"
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See detailPlantes toxiques et champignons vénéneux de notre environnement
Angenot, Luc ULg

Scientific conference (1998, June 13)

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See detailStrychnochrysine, a New Bisindole Alkaloid from the Roots of Strychnos Nux-Vomica
Biala, Rose Gadi; Tits, Monique ULg; Penelle, Jacques et al

in Journal of Natural Products (1998), 61(1), 139-41

The reinvestigation of Strychnos nux-vomica resulted in the isolation of a colored monoquaternary bisindole alkaloid from the roots. The structure of this new orange substance, strychnochrysine (1), was ... [more ▼]

The reinvestigation of Strychnos nux-vomica resulted in the isolation of a colored monoquaternary bisindole alkaloid from the roots. The structure of this new orange substance, strychnochrysine (1), was defined by detailed spectroscopic methods. [less ▲]

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See detailThe DNA intercalating alkaloid cryptolepine interferes with topoisomerase II and inhibits primarily DNA synthesis in B16 melanoma cells.
Bonjean, K.; De Pauw, Marie-Claire ULg; Defresne, Marie-Paule ULg et al

in Biochemistry (1998), 37(15), 5136-46

Cryptolepine hydrochloride is an indoloquinoline alkaloid isolated from the roots of Cryptolepis sanguinolenta. It is characterized by a multiplicity of host-mediated biological activities, including ... [more ▼]

Cryptolepine hydrochloride is an indoloquinoline alkaloid isolated from the roots of Cryptolepis sanguinolenta. It is characterized by a multiplicity of host-mediated biological activities, including antibacterial, antiviral, and antimalarial properties. To date, the molecular basis for its diverse biological effects remains largely uncertain. Several lines of evidence strongly suggest that DNA might correspond to its principal cellular target. Consequently, we studied the strength and mode of binding to DNA of cryptolepine by means of absorption, fluorescence, circular, and linear dichroism, as well as by a relaxation assay using DNA topoisomerases. The results of various optical and gel electrophoresis techniques converge to reveal that the alkaloid binds tightly to DNA and behaves as a typical intercalating agent. In DNAase I footprinting experiments it was found that the drug interacts preferentially with GC-rich sequences and discriminates against homo-oligomeric runs of A and T. This study has also led to the discovery that cryptolepine is a potent topoisomerase II inhibitor and a promising antitumor agent. It stabilizes topoisomerase II-DNA covalent complexes and stimulates the cutting of DNA at a subset of preexisting topoisomerase II cleavage sites. Taking advantage of the fluorescence of the indoloquinoline chromophore, fluorescence microscopy was used to map cellular uptake of the drug. Cryptolepine easily crosses the cell membranes and accumulates selectively into the nuclei rather than in the cytoplasm of B16 melanoma cells. Quantitative analyses of DNA in cells after Feulgen reaction and image cytometry reveal that the drug blocks the cell cycle in G2/M phases. It is also shown that the alkaloid is more potent at inhibiting DNA synthesis rather than RNA and protein synthesis. Altogether, the results provide direct evidence that DNA is the primary target of cryptolepine and suggest that this alkaloid is a valid candidate for the development of tumor active compounds. [less ▲]

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See detail3 ',4 ',5 ',6 ' tetradehydrolongicaudatine Y, an anhydronium base from Strychnos usambarensis
Frederich, Michel ULg; Quetin-Leclercq, J.; Biala, R. G. et al

in Phytochemistry (1998), 48(7), 1263-1266

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See detailQualitative and quantitative evaluation of bisindole usambarane alkaloids in Strychnos usambarensis roots by high performance liquid chromatography diode-array
Frederich, Michel ULg; Tits, Monique ULg; Angenot, Luc ULg

in Phytochemical Analysis [=PCA] (1998), 9(2), 63-66

A high performance liquid chromatographic method for the simultaneous determination of bisindole usambarane alkaloids from the roots of Strychnos usambarensis using a diode-array detector is proposed, The ... [more ▼]

A high performance liquid chromatographic method for the simultaneous determination of bisindole usambarane alkaloids from the roots of Strychnos usambarensis using a diode-array detector is proposed, The system, consisting of a RP-8 Select B column and a linear gradient elution with acetonitrile and acetate buffer allowed the separation of all the alkaloids in 20 min, Usambarensine was found to be the major tertiary alkaloid present in the roots, In order to demonstrate the possibility of quantifying the bisindole alkaloids in crude roots extracts, the quantitative evaluation of 3',4'-dihydrousambarensine, usambarensine and N-b-methylusambarensine was carried out. (C) 1998 John Wiley & Sons, Ltd. [less ▲]

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See detailDirect Quantitative Analysis of Linamarin in Cassava by High-Performance Thin Layer Chromatography
Bodart, Patricia; Penelle, Jacques; Angenot, Luc ULg et al

in Journal of Planar Chromatography- Modern TLC (1998), 11(January/February), 38-42

A simple, rapid and accurate HPTLC quantitative procedure is presented for the direct determination of linamarin. A cassava sample was extracted with boiling 80% v/v methanol and the extract and linamarin ... [more ▼]

A simple, rapid and accurate HPTLC quantitative procedure is presented for the direct determination of linamarin. A cassava sample was extracted with boiling 80% v/v methanol and the extract and linamarin were applied to silicagel HPTLC plates prewashed by development with methanol.The plates were first developed to a distance of 30mm with ethyl acetate-acetone-water, 40+50+10 (v/v), then to a distance of 85 mm with ethyl acetate-formic acid-water, 60+10+10 (v/v). the spots were visualized by dipping the plate into a solution af aniline (2%), and phosphoric acid 15% in acetone, then heating at 105°C for 60 min. Densitometric quantification was effected at lambda= 525 nm by transmission scanning. The method was validated for accuracy, intraday, and interday reproducibility of peak area, linearity, and detection limit. [less ▲]

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See detailDirect quantitative analysis of linamarin in cassava by high performance thin-layer chromatography
Bodart, Patricia; Muzembe, K. F.; Penelle, Jacques et al

Conference (1997, April)

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See detailAlfred-Charles GILKINET
Lecomte, Jean; Angenot, Luc ULg

in Annuaire 1997 de l'Académie Royale de belgique (1997)

Alfred-Charles GILKINET est né à Ensival en 1845 et décédé à Manhay en 1926. Il fut Correspondant de la Classe des sciences en 1875 et Directeur en 1897. Il était Pharmacien, Docteur en sciences et ... [more ▼]

Alfred-Charles GILKINET est né à Ensival en 1845 et décédé à Manhay en 1926. Il fut Correspondant de la Classe des sciences en 1875 et Directeur en 1897. Il était Pharmacien, Docteur en sciences et Paléobotaniste. Il fut Professeur de Pharmacie à l'Université de lLège et directeur de l'Institut de pharmacie (le premier construit en Belgique) dont il avait obtenu la construction en 1883 à l'angle de la rue Fusch et de la rue Courtois dans le quartier du jardin Botanique de Liège.Il fut admis à l'éméritat en 1919 à l'âge de 74 ans! [less ▲]

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See detailCharacterization of non pigmented B16 melanoma cell-derived cytotoxic factors.
Siwek, B.; De Pauw, Marie-Claire ULg; Quetin-Leclercq, J. et al

in Chemico-Biological Interactions (1997), 103(1), 59-73

We analyzed and tried to characterize substance(s) responsible for cytotoxic activities detected in culture media conditioned by non pigmented B16 melanoma cells (NPB16). The different cytological tests ... [more ▼]

We analyzed and tried to characterize substance(s) responsible for cytotoxic activities detected in culture media conditioned by non pigmented B16 melanoma cells (NPB16). The different cytological tests used showed that ultrafiltrated conditioned media (CM U1 fraction) contained several cytotoxic factors with a Mw lower than 1000 Da. These factors seemed to act either directly or indirectly on cell membranes, mitochondria, on the cell cycle and on protein and DNA synthesis. A cytotoxic activity could be found even after high dilution of CM U1. These cytotoxic factors were rapidly released by B16 cells in culture, independently of cell confluence. Their activities in the treated cells were also very fast and the cytotoxic effects were irreversible after only a few hours of treatment. These factors were not intermediate products during melanogenesis, neither polyamines, nor proteases. At least one of them seemed to be a small acidic and basic stable peptide without disulfide bounds but not heat stable. The synthesis of at least one of these cytotoxic factors was inhibited by cycloheximide and the cytotoxic activity was partially destroyed by pronase and trypsin, but not by pepsin. The cytotoxicity was not modified by copper complexants or free radical inhibitors (bovine serum albumin (BSA), tyrosine, superoxyde dismutase (SOD), catalase, vitamin E). Furthermore the levels of glutathione peroxydase activity and reduced glutathione did not change after treatment by CM U1 as compared to controls. [less ▲]

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See detailGlucoindole alkaloids from stem bark of Strychnos mellodora
Brandt, Viviane; Tits, Monique ULg; Angenot, Luc ULg

Conference (1996, May)

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See detailGlucoindole alkaloids from stem bark of Strychnos mellodora
Brandt, V; Tits, Monique ULg; Angenot, Luc ULg

Poster (1996, February)

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See detailGlucoindole Alkaloids from Stem Bark of Strychnos Mellodora
Tits, Monique ULg; Brandt, V.; Wauters, Jean-Noël ULg et al

in Planta Medica (1996), 62(1), 73-4

Three glucoindole alkaloids, dolichantoside (1), strictosidine (2), and palicoside (3), have been identified in the stem bark of Strychnos mellodora (Loganiaceae), collected in Zimbabwe. The chiroptical ... [more ▼]

Three glucoindole alkaloids, dolichantoside (1), strictosidine (2), and palicoside (3), have been identified in the stem bark of Strychnos mellodora (Loganiaceae), collected in Zimbabwe. The chiroptical (CD) data are compared. [less ▲]

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See detailPharmacologie - Suivre la Flèche
Lambert, Philippe; Angenot, Luc ULg

Article for general public (1996)

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See detail9-Methoxygeissoschizol, an alkaloid from bark of strychnos guianensis
Mavar-Manga, Hélène; Quetin-Leclercq, Joëlle; Llabres, Gabriel ULg et al

in Phytochemistry (1996), 43(5), 1125-1127

The isolation and structure determination of 9-methoxygeissoschizol from the stem bark of Strychnos guianensis is described. Elucidation of its structure is mainly based on NMR studies.

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