References of "Llabres, Gabriel"
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See detailImproved PRESS sequence for lactate detection in the human vitreous body
Balteau, Evelyne ULg; COLLIGNON, Nathalie ULg; Robe, Pierre ULg et al

in Proceedings of the International Society for Magnetic Resonance in Medicine (2006), 14

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See detailGuanidinium chloride denaturation of the dimeric Bacillus licheniformis Blal repressor highlights an independent domain unfolding pathway
Vreuls, Christelle ULg; Filée, Patrice ULg; Van Melckebeke, H. et al

in Biochemical Journal (2004), 384(Pt 1), 179-190

The Bacillus licheniformis 74911 BlaI repressor is a prokaryotic regulator that, in the absence of a P-lactam antibiotic, prevents the transcription of the blaP gene, which encodes the BlaP beta-lactamase ... [more ▼]

The Bacillus licheniformis 74911 BlaI repressor is a prokaryotic regulator that, in the absence of a P-lactam antibiotic, prevents the transcription of the blaP gene, which encodes the BlaP beta-lactamase. The BlaI repressor is composed of two structural domains. The 82-residue NTD (N-terminal domain) is a DNA-binding domain, and the CTD (C-terminal domain) containing the next 46 residues is a dimerization domain. Recent studies have shown the existence of the monomeric, dimeric and tetrameric forms of BlaI in solution. In the present study, we analyse the equilibrium unfolding of BlaI in the presence of GdmCl (guanidinium chloride) using different techniques: intrinsic and ANS (8-anilinonaphthalene-1-sulphonic acid) fluorescence, far- and near-UV CD spectroscopy, cross-linking, analytical ultracentrifugation, size exclusion chromatography and NMR spectroscopy. In addition, the intact NTD and CTD were purified after proteolysis of BlaI by papain, and their unfolding by GdmCl was also studied. GdmCl-induced equilibrium unfolding was shown to be fully reversible for BlaI and for the two isolated fragments. The results demonstrate that the NTD and CTD of BlaI fold/unfold independently in a four-step process, with no significant cooperative interactions between them. During the first step, the unfolding of the Blal CTD occurs, followed in the second step by the formation of an 'ANS-bound' intermediate state. Crosslinking and analytical ultracentrifugation experiments suggest that the dissociation of the dimer into two partially unfolded monomers takes place in the third step. Finally, the unfolding of the Blal NTD occurs at a GdmCI concentration of approx. 4 M. In summary, it is shown that the Blal CTD is structured, more flexible and less stable than the NTD upon GdmCI denaturation. These results contribute to the characterization of the Blal dimerization domain (i.e. CTD) involved in the induction process. [less ▲]

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See detailDiterpenes from the leaves of Croton Zambesicus
Block, Sébastien; Baccelli, Chiara; Tinant, Bernard et al

in Phytochemistry (2004), 65

Two new trachylobane- and one isopimarane-type diterpenoids: ent-18-hydroxy-trachyloban-3-one; ent-trachyloban-3-one; isopimara-7,15-dien-3b-ol, were isolated from the leaves of Croton zambesicus ... [more ▼]

Two new trachylobane- and one isopimarane-type diterpenoids: ent-18-hydroxy-trachyloban-3-one; ent-trachyloban-3-one; isopimara-7,15-dien-3b-ol, were isolated from the leaves of Croton zambesicus, together with trans-phytol, b-sitosterol, a-amyrin and stigmasterol. The structures were determined by extensive NMR techniques and X-ray analysis. The cytotoxicity of these compounds has been evaluated on cancer and non-cancer cell-lines. [less ▲]

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See detailPhysique (J. Kane & M. Sternheim)
Ghosez, Philippe ULg; Hoebeke, Maryse ULg; Llabres, Gabriel ULg

Book published by Dunod - 3rd ed. (2004)

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See detailSolution structural study of BlaI: Implications for the repression of genes involved in beta-lactam antibiotic resistance
Van Melckebeke, H.; Vreuls, Christelle ULg; Gans, P. et al

in Journal of Molecular Biology (2003), 333(4), 711-720

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See detailInfluence of cyclodextrins on the solubility and the stability of cyproterone acetate
Henry de Hassonville, Sandrine; Dive, Georges ULg; Prosperi, Christelle ULg et al

Conference (2003, May)

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See detailSolution structural study of BlaI: implications for the repression of genes involved in beta-lactam antibiotic resistance.
Melckebeke, Helene Van; Vreuls, Christelle ULg; Gans, Pierre et al

in Journal of Molecular Biology (2003), 333(4), 711-20

beta-Lactamase and penicillin-binding protein PBP2' mediate staphylococcal resistance to beta-lactam antibiotics, which are otherwise highly clinically effective. Two repressors (BlaI and MecI) regulate ... [more ▼]

beta-Lactamase and penicillin-binding protein PBP2' mediate staphylococcal resistance to beta-lactam antibiotics, which are otherwise highly clinically effective. Two repressors (BlaI and MecI) regulate expression of these inducible proteins. Here, we present the first solution structure of the 82 amino acid residue DNA-binding domain of Bacillus licheniformis BlaI which is very similar in primary sequence to the medically significant Staphyloccocal BlaI and MecI proteins. This structure is composed of a compact core of three alpha-helices and a three-stranded beta-sheet typical of the winged helix protein (WHP) family. The protein/DNA complex was studied by NMR chemical shift comparison between the free and complexed forms of BlaI. Residues involved in DNA interaction were identified and a WHP canonical model of interaction with the operators is proposed. In this model, specific contacts occur between the base-pairs of the TACA motif and conserved amino acid residues of the repressor helix H3. These results help toward understanding the repression and induction mechanism of the genes coding for beta-lactamase and PBP2'. [less ▲]

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See detailNew 3-deoxyanthocyanidins from leaves of Arrabidaea chica
Devia, B.; Llabres, Gabriel ULg; Wouters, J. et al

in Phytochemical Analysis [=PCA] (2002), 13(2, Mar-Apr), 114-120

Two new 3-deoxyanthocyanidins, 6,7,3',4'-tetrahydroxy-5-methoxyflavylium and 6,7,4'-trihydroxy-5-methoxyflavylium, and the pigment carajurin, which has been previously identified, were isolated from dried ... [more ▼]

Two new 3-deoxyanthocyanidins, 6,7,3',4'-tetrahydroxy-5-methoxyflavylium and 6,7,4'-trihydroxy-5-methoxyflavylium, and the pigment carajurin, which has been previously identified, were isolated from dried leaves of Arrabidaea chica, a creeper native to the American tropics. The structures of the components were elucidated by H-1- and C-13-NMR spectroscopy and HPLC-MS, including X-ray crystallographic analysis for carajurin. Copyright (C) 2002 John Wiley Sons, Ltd. [less ▲]

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See detailEnt-Trachyloban-3beta-ol, a new cytotoxic diterpene frm Croton zambesicus
Block, Sebastien; Stevigny, Caroline; Gillet, Marie-Claire ULg et al

in Planta Medica (2002), 68

The dichloromethane extract of leaves of Croton Zambesicus (Euphorbiaceae) showing in vitro cytotoxicity against huma cervix carcinoma cells was investigated in order to identify its active compounds. A ... [more ▼]

The dichloromethane extract of leaves of Croton Zambesicus (Euphorbiaceae) showing in vitro cytotoxicity against huma cervix carcinoma cells was investigated in order to identify its active compounds. A bio-guided fractionation by HSCCC followed by MPLC led us to isolate a trachylobane diterpene, ent-trachyloban-3beta-ol, with cytotoxic properties (IC50 on HeLa cells = 7.3 ùg/ml). This is the first report on the cytotoxicity of a trachylobane diterpene. [less ▲]

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See detailCytotoxic aporphine alkaloids from Cassytha filiformis.
Stevigny, C.; Block, S.; De Pauw, Marie-Claire ULg et al

in Planta Medica (2002), 68(11), 1042-4

Purification of a cytotoxic crude alkaloid extract of Cassytha filiformis led to the isolation of four known aporphine alkaloids: neolitsine, dicentrine, cassythine (= cassyfiline) and actinodaphnine ... [more ▼]

Purification of a cytotoxic crude alkaloid extract of Cassytha filiformis led to the isolation of four known aporphine alkaloids: neolitsine, dicentrine, cassythine (= cassyfiline) and actinodaphnine. Their structures were determined by analysis of spectroscopic data. All isolated alkaloids were tested for their cytotoxic activities on cancer and non-cancer cell lines in vitro. Neolitsine was the most active against HeLa and 3T3 cells (IC 50 :21.6 microM, and 21.4 microM, respectively). Cassythine and actinodaphnine showed the highest activity against Mel-5 (IC 50 : 24.3 microM and 25.7 microM, respectively) and HL-60 (IC 50 : 19.9 microM and 15.4 microM, respectively). This is the first report on the cytotoxic activity of C. filiformis extract and of neolitsine and cassythine. Furthermore, the complete NMR data of cassythine and actinodaphnine are given here for the first time. [less ▲]

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See detailCytotoxic aporphine alkaloids from Cassytha filiformis L
Stévigny, caroline; Gillet, Marie-Claire ULg; de Hoffmann, E et al

Poster (2001)

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See detailNew Antimalarial and Cytotoxic Sungucine Derivatives from Strychnos Icaja Roots
Frederich, Michel ULg; Gillet, Marie-Claire ULg; Llabres, Gabriel ULg et al

in Planta Medica (2000), 66(3), 262-9

Reinvestigation of Strychnos icaja Baillon resulted in the isolation of vomicine, isostrychnine and of three new sungucine derivatives, named isosungucine (8), 18-hydroxy-sungucine (9) and 18-hydroxy ... [more ▼]

Reinvestigation of Strychnos icaja Baillon resulted in the isolation of vomicine, isostrychnine and of three new sungucine derivatives, named isosungucine (8), 18-hydroxy-sungucine (9) and 18-hydroxy-isosungucine (10). They were identified by detailed spectroscopic methods. The complete 1H- and 13C-NMR study of sungucine was also realized. Some of these compounds were highly active against Plasmodium falciparum in vitro and more particularly against the chloroquine-resistant strain. Compound 10 showed a selective antiplasmodial activity, with > 100-fold greater toxicity towards Plasmodium falciparum, relative to cultured human cancer cells (KB and HeLa lines) or fibroblasts (WI38). [less ▲]

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See detail10'-Hydroxyusambarensine, a New Antimalarial Bisindole Alkaloid from the Roots of Strychnos Usambarensis
Frederich, Michel ULg; Tits, Monique ULg; Hayette, Marie-Pierre ULg et al

in Journal of Natural Products (1999), 62(4), 619-21

Reinvestigation of Strychnos usambarensis Gilg resulted in the isolation of a tertiary phenolic bisindole alkaloid, 10'-hydroxyusambarensine (1), which was identified by detailed spectroscopic methods ... [more ▼]

Reinvestigation of Strychnos usambarensis Gilg resulted in the isolation of a tertiary phenolic bisindole alkaloid, 10'-hydroxyusambarensine (1), which was identified by detailed spectroscopic methods. Compound 1 was moderately active against two strains of Plasmodium falciparum in vitro. [less ▲]

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See detailDevelopment of a parenteral and of an oral formulation of albendazole with cyclodextrins
Piel, Géraldine ULg; Evrard, Brigitte ULg; Van Hees, Thierry ULg et al

in STP Pharma Sciences (1999), 3

L'albendazole est une dérivé benzimidazole à large spectre d'activité contre les parasites helminthiques de l'homme et de l'animal. L'albendazole est très faiblement soluble dans l'eau. Il a été démontré ... [more ▼]

L'albendazole est une dérivé benzimidazole à large spectre d'activité contre les parasites helminthiques de l'homme et de l'animal. L'albendazole est très faiblement soluble dans l'eau. Il a été démontré que les cyclodextrines sont capables de former des complexes d'inclusion avec l'albendazole et d'en augmenter la solubilité. La solubilité aqueuse de l'albendazole est dépendante du pH. Le but de ce travail est d'étudier l'influence combinée des cyclodextrines et de différents acides sur la solubilité de l'albendazole. Il a été démontré qu'il existe un véritable effet synergique entre les cyclodextrines et les différents acides. L'utilisation combinée d'hydroxypropyl-b-cyclodextrine (200 mM) et d'acide lactique ou acide citrique (50 mM) permet de dissoudre plus de 1 mg/ml d'albendazole. Des études RMN ont démontré l'inclusion de l'albendazole dans la b-cyclodextrine en milieu acide. Ces résultats montrent qu'il est possible de réaliser une solution injectable et une solution orale d'albendazole grâce aux cyclodextrines. [less ▲]

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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 ▲]

Detailed reference viewed: 62 (29 ULg)