References of "Severin, M"
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See detailChemical Characterization Of Tylosema-Fassoglensis (Kotschy) Torre And Hillc Oilseed
Dubois, Michel ULg; Lognay, Georges ULg; Baudart, E. et al

in Journal of the Science of Food and Agriculture (1995), 67(2), 163-167

Tylosema fassoglensis seeds contain high levels of lipids (240–300 g kg−1) and proteins (446 g kg−1 dry weight). Major fatty acids contained in the oil are linoleic (36–42% of the total fatty acids) oleic ... [more ▼]

Tylosema fassoglensis seeds contain high levels of lipids (240–300 g kg−1) and proteins (446 g kg−1 dry weight). Major fatty acids contained in the oil are linoleic (36–42% of the total fatty acids) oleic (32–35%) and palmitic (11.5–15.7%) acids. The proteins are characteristic with their high levels of lysine, proline and tyrosine. Due to their very low content, both methionine and cystine appear to be the limiting amino acids. Tylosema fassoglensis defatted meal contains substantial amounts of trypsin inhibitors and phytates 295 TUI mg−1 and 35 g kg−1 dry weight, respectively. [less ▲]

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See detailAssessment of lipoxygenase activity in seed extracts from 35 plant species
Fauconnier, Marie-Laure ULg; Vanzeveren, E.; Marlier, Michel et al

in Grasas y Aceites (1995), 46(1), 6-10

Lipoxyganase activity in 35 seed extracts was determined an the basis of hydroperoxide synthesis using linoleic acid as substrate. The results referring to the extracted protein content show that several ... [more ▼]

Lipoxyganase activity in 35 seed extracts was determined an the basis of hydroperoxide synthesis using linoleic acid as substrate. The results referring to the extracted protein content show that several species of Vigna (V. unguiculata, V. radiata and V. mungo) and one of Trifolium exhibit stronger lipoxygenase activity than soybean enzyme extracts. The pH-activity relationship was also established for 4 very active samples. GCMS analysis revealed equal amounts of 9- and 13 hydroperoxides of linoleic acid In these seed extracts, indicating no enzyme positional specificity. [less ▲]

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See detailMeasurement of glucosinolates in rapeseeds.
Wathelet, Jean-Paul ULg; Marlier, M.; Severin, M. et al

in Natural toxins (1995), 3(4),

Several ring tests have been organized by the International Organisotion for Standardization (lSO) and the Measurement ônd Testing Programme (BCR) for improving glucosinolote methods Finally, HPLC of ... [more ▼]

Several ring tests have been organized by the International Organisotion for Standardization (lSO) and the Measurement ônd Testing Programme (BCR) for improving glucosinolote methods Finally, HPLC of desulphoglucosinolates is recommended by lSO, the European Committee for Standardizotion (CEN), and the European Commission (EC) as the official method. X-ray fluorescence has also become particularly common for fast analysis. After checking stability of intact glucosinolates in whole rapeseeds, the BCR has three reference materials (CRM 366, CRM 190, CRM 367) avai able, certified for their total glucosinolate and sulphur contents. Currently, the Measurement and Testing Programme is supporting a research project concerning the stdbility of desulphoglucosinolates and intact glucosinolates extracts. At the present time, best results were observed with lyophilized extracts sealed in brown glass ampoules and stored at 18'C. [less ▲]

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See detailGas chromatography-mass spectrometry study of terpenoids produced by shoot cultures of Artemisia annua L.
Marlier, M.; Fauconnier, Marie-Laure ULg; Jaziri, M. et al

Poster (1994, June 12)

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See detailTemporal and spatial variations of root tip density and ergosterol content of mycorrhizal roots of Picea abies Karst. and Fagus sylvatica L.
van Praag, H. J.; Lognay, Georges ULg; Carletti, G. et al

in Soil Biology & Biochemistry (1994), 26(7), 833-840

Seasonal variations of mycorrhizal colonisation of European beech, Fagus sylvatica L. and Norway spruce, Picea abies Karst., rootlets in two stands, were investigated by comparing ergosterol content and ... [more ▼]

Seasonal variations of mycorrhizal colonisation of European beech, Fagus sylvatica L. and Norway spruce, Picea abies Karst., rootlets in two stands, were investigated by comparing ergosterol content and very-fine root tip counts for a 3 yr period. Significant correlations and interactions between three environmental factors, ‘year’, ‘season’ and ‘horizon’ and the measured data, were interpreted. It was shown that root tip counting together with ergosterol analysis of rootlets enables us to follow changes induced by the environment on a long-term basis. [less ▲]

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See detailTylosema fassoglensis (Kotschy) Torre and Hillc.: a lesser knownplant
Dubois, M.; Malaisse, François ULg; Buyck, B. et al

in Cahiers d'Etudes et de Recherches Francophones. Agricultures (1994), 3

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See detailImprovement Of Enzymatic-Synthesis Yields Of Flavor Acetates - The Example Of The Isoamyl Acetate
Razafindralambo, Hary ULg; Blecker, Christophe ULg; Lognay, Georges ULg et al

in Biotechnology Letters (1994), 16(3), 247-250

Isoamyl acetate synthesis was chosen as a model to improve flavour acetate yields by optimising the enzymatic reaction. Alcohol:acid molar ratio, temperature, water content and amount of enzyme effects ... [more ▼]

Isoamyl acetate synthesis was chosen as a model to improve flavour acetate yields by optimising the enzymatic reaction. Alcohol:acid molar ratio, temperature, water content and amount of enzyme effects were analyzed. The optimum values were respectively 4, 45 degrees C, 0,1% (w/v) and 0,5 g. In these conditions, the synthesis yield reached 80% after 24 h of reaction and was found 15 times greater than those already reported in the literature. [less ▲]

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See detailDetection des molecules responsables de l'activite biocide des feuilles de Boscia senegalensis (Pers.) Lam ex Poir. par echantillonage d'espace de tete et spectrometrie de masse couplee a la chromatographie en phase gazeuse.
Lognay, Georges ULg; Marlier, M.; Seck, D. et al

in Bulletin des Recherches Agronomiques de Gembloux (1994), 29(1),

Des échantillons de feuilles de Boscia senegalensis (Prns.) I.ev ex Porn. ont été tnaintenus dans des conditions contrôlées sous un flux d'hélium, à l'intérieur d'une.platine de désorption thermique ... [more ▼]

Des échantillons de feuilles de Boscia senegalensis (Prns.) I.ev ex Porn. ont été tnaintenus dans des conditions contrôlées sous un flux d'hélium, à l'intérieur d'une.platine de désorption thermique directement connectée à un GC-MS. A côté du trans-2-hexénal, responsable de la note "verte" des feuilles, l'isothiocyanate de méthyle et le cyanure de méthyle (acétonitrile) ont été détectés. Ces deux produits se sont formés par dégradation enzymatique in situ d'un précurseur, la glucocapparine. Ils ont été caractérisés par leur spectre de masse. La libération de cyanure de méthyle à partir d'échantillons biologiques est expliquée. [less ▲]

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See detailThe Certification Of The Identity Of Individual Sterols In 3 Bcr Oil And Fat Reference Materials By Gc-Ms
Lognay, Georges ULg; Lacoste, F.; Marlier, M. et al

in Fett : Zeitschrift für Wissenschaft und Technologie der Fette, Öle und Wachse = Lipid : Journal for Science and Technology of Fats, Oils and Waxes (1993), 95(3), 98104

The sterols of three Reference Materials: a vegetable oil (RM162: a mixture of Soya oil and Maize oil) and two animal fats (RM163: a blend of Pig and Beef fats and RM164: Milkfat) were identified by GC-MS ... [more ▼]

The sterols of three Reference Materials: a vegetable oil (RM162: a mixture of Soya oil and Maize oil) and two animal fats (RM163: a blend of Pig and Beef fats and RM164: Milkfat) were identified by GC-MS in two experienced laboratories. The techniques used were practically the same nevertheless, Lab. 1 and 2 used respectively an HPLC and a classical TLC method to isolate the sterols from the unsaponifiable matter. Many minor components were detectable when the high efficient HPLC fractionation technique was used but the only molecules similarly identified by the two Labs were considered for the certification of sterol identities. In this article, we present the results of the certification study together with the interpretation of mass spectra. [less ▲]

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See detailBiological-Activity Of Cassia-Occidentalis L Against Callosobruchus-Maculatus (F) (Coleoptera, Bruchidae)
Lienard, V.; Seck, D.; Lognay, Georges ULg et al

in Journal of Stored Products Research (1993), 29(4), 311318

In developing countries, traditional control methods are commonly used against stored-product insects and mites. In Senegal, the leaves of Cassia occidentalis L. (Caesalpiniaceae) are used to protect ... [more ▼]

In developing countries, traditional control methods are commonly used against stored-product insects and mites. In Senegal, the leaves of Cassia occidentalis L. (Caesalpiniaceae) are used to protect cowpea seeds (Vigna unguiculata L. (Walpers)) against Callosobruchus maculatus (Coleoptera: Bruchidae). The biological activity of the leaves, the seeds and oil of C. occidentalis was evaluated in controlled conditions (28 ± 2°C, 45 ± 5% r.h.) against C. maculatus. At the rate of 10% (w/w), both fresh and dry leaves as well as whole and ground seeds had no contact toxicity on the cowpea beetle. In contrast, seed oil induced an increase in mortality of C. maculatus eggs and first larval instar at the concentration of 10 ml/kg cowpea. The basis of the ovicidal and larvicidal activities are discussed in this paper. Several trials using pure compounds have highlighted that several fatty acids (linoleic, oleic and stearic) are responsible for C. occidentalis toxicity. C. occidentalis seed oil did not reduce the oviposition of C. maculatus at 10 ml/kg seed. [less ▲]

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See detailEssential oil production by Anthemis nobilis L. tissue culture.
Fauconnier, Marie-Laure ULg; Jaziri, M.; Marlier, Michel et al

in Journal of Plant Physiology (1993), 141(6), 759-761

The production of essential oil by tissue culture s ol Antbemis nobilis L. including cell suspension, shoot and crown-gall cultures is reported. The biosynthetic capability of these different cultures was ... [more ▼]

The production of essential oil by tissue culture s ol Antbemis nobilis L. including cell suspension, shoot and crown-gall cultures is reported. The biosynthetic capability of these different cultures was compared with that of plants grown in a field. The addition of crude polysaccharide fraction prepared from yeast extract and from the plant itself to shoot cultures affected the composition and total essential content (from 0.08 o/o to 0.3Qo/o dry weight). The essential oil content of the crown-gall tissue ol A. nobilis was 0.25 % of the dry weight and the composition of the essential oil was comparable to that of the flowers. [less ▲]

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See detailTHE CERTIFIED TOTAL GLUCOSINOLATE CONTENT IN 3 RAPESEEDS (CRM-190, CRM-366 AND CRM-367)
Wathelet, Jean-Paul ULg; WAGSTAFFE, P. J.; BOENKE, A. et al

in Fresenius' Journal of Analytical Chemistry (1993), 347(10-11), 396-399

The preparation of certified rapeseed reference materials and the steps taken to establish the certified values for total glucosinolate contents are described. Details are given of the studies to ... [more ▼]

The preparation of certified rapeseed reference materials and the steps taken to establish the certified values for total glucosinolate contents are described. Details are given of the studies to demonstrate the homogeneity and stability of the material. The results of the certification exercise for total glucosinolate content, which involved European laboratories who applied a variety of methods (high-pressure liquid chromatography, gas liquid chromatography, determination of enzymatically released glucose and sulphate), are presented and discussed. The certified values for the glucosinolate content (mumol/g of non-defatted whole seeds) and the 95% confidence level are the following: CRM 366 (12.1 +/- 0.8 mumol/g), CRM 190 (25.5 +/- 0.9 mumol/g) and CRM 367 (102.4 +/- 3 mumol/g) (CRM = certified reference material). Indicative values (not certified) for individual glucosinolates are also given. Certified sulphur values (mg/g of non defatted whole seeds) have been determined by other laboratories: CRM 366 (3.41 +/- 0.12 mg/g), CRM 190 (4.93 +/- 0.15 mg/g) and CRM 367 (10.5 +/- 0.40 mg/g). [less ▲]

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See detailCHARACTERIZATION OF 3 LABDANE DITERPENES FROM AFRAMOMUM-ALBOVIOLACEUM
Marlier, Michel; LEGUELLEC, G.; Lognay, Georges ULg et al

in Planta Medica (1993), 59(5), 455-457

Two labdane diterpenes were isolated from the seeds and the rhizomes of Aframomum alboviolaceum (Ridley) K. Schum (Zingiberaceae) and identified by GC-MS, H-1-, and C-13-NMR as (E)-labda-8(17),12-diene-15 ... [more ▼]

Two labdane diterpenes were isolated from the seeds and the rhizomes of Aframomum alboviolaceum (Ridley) K. Schum (Zingiberaceae) and identified by GC-MS, H-1-, and C-13-NMR as (E)-labda-8(17),12-diene-15,16-dial (1) and (E)-8beta,17-epoxylabd-12-ene-15,16-dial (2). A third minor compound could be the methyl (E)-14xi,15-epoxylabd-8(17), 12-dien-16-oate. The simultaneous occurrence of these three molecules has been mentioned only in one other species of the same genus, Aframomum daniellii (1). [less ▲]

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See detailBIOLOGICAL-ACTIVITY OF THE SHRUB BOSCIA-SENEGALENSIS (PERS) LAM EX-POIR (CAPPARACEAE) ON STORED GRAIN INSECTS
SECK, D.; Lognay, Georges ULg; Haubruge, Eric ULg et al

in Journal of Chemical Ecology (1993), 19(2), 377-389

Biological activity of leaves, fruits and extract of the African shrub Boscia senegalensis (PERS.) LAM. ex Poir. was evaluated against five stored-grain insects. When added to cowpeas at 2-4% (w/w), fresh ... [more ▼]

Biological activity of leaves, fruits and extract of the African shrub Boscia senegalensis (PERS.) LAM. ex Poir. was evaluated against five stored-grain insects. When added to cowpeas at 2-4% (w/w), fresh ground fruits and leaves caused 80-100% mortality in Callosobruchus maculatus (F.) adults and significantly reduced both emergence and damage of the F1 progeny. Acetone fruit extract exhibited a potent fumigant effect on Prostephanus truncatus HORN., C maculatus, and Sitotroga cerealella OLIV.: with LT50 values of 3.8, 2.3, and below 1.5 hr, respectively. LC50 determination for B. senegalensis fruits and leaves as well as pure methylisothiocyanate (MITC) on Tribolium castaneum HERBST, Sitophilus zeamais MOTSCH. and C. maculatus showed a differential response of the insects to plant parts or MITC. Quantitative dosage of Boscia active components and LC50 values obtained for the plant tissues, compared to those of pure molecules, indicate that the biological activity of B. senegalensis is due to the liberation of MITC from a glucosinolate precursor glucocapparin contained in Boscia fruits and leaves. [less ▲]

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See detailIdentification of elemental sulphur (S8) in Boscia senegalensis (Pers.) Lam ex Poir. leaves.
Lognay, Georges ULg; Seck, D.; Marlier, M. et al

in Bulletin des Recherches Agronomiques de Gembloux (1993), 28(4),

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See detailProduction of essential oil by in vitro culture of Anthemis nobilis L. and characterization by GC-MS.
Marlier, M.; Fauconnier, Marie-Laure ULg; Jaziri, M. et al

Poster (1992, September 21)

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See detailEdible Fats And Oils Reference Materials For Sterols Analysis With Particular Attention To Cholesterol .1. Investigation Of Some Analytical Aspects By Experienced Laboratories
Lognay, Georges ULg; Severin, M.; Boenke, A. et al

in Analyst (1992), 117(7), 1093-1097

The work reported here is integrated into a programme organized by the Community Bureau of Reference with the aim of developing edible oil reference materials (RMs) certified for cholesterol content. One ... [more ▼]

The work reported here is integrated into a programme organized by the Community Bureau of Reference with the aim of developing edible oil reference materials (RMs) certified for cholesterol content. One vegetable oil (RM 162, a blend of soya and maize oils) and two animal fats (RM 163, a blend of pig and beef fats, and RM 164, an anhydrous milk fat) possessing, respectively, low, medium and high cholesterol contents were chosen for this purpose. The present paper summarizes the analytical conclusions resulting from three interlaboratory trials carried out to identify and correct for the major sources of random and systematic errors linked to the protocol and to the gas–liquid chromatographic analysis. Several improvements to the methodology, and recommendations, have been proposed for the determination of individual sterols within the certification exercise. The latter will be reported elsewhere. [less ▲]

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See detailDexamethasone Bovine Pharmacokinetics
Gaignage, P.; Lognay, Georges ULg; Bosson, D. et al

in European Journal of Drug Metabolism and Pharmacokinetics (1991), 16(3), 219-221

Dexamethasone phosphate (DXM-PHO) is an ester which is quickly hydrolysed by the bovine and the dexamethasone (DXM) plasma half-life was 5.16 h. It has been demonstrated that 54 h after DXM-PHO injection ... [more ▼]

Dexamethasone phosphate (DXM-PHO) is an ester which is quickly hydrolysed by the bovine and the dexamethasone (DXM) plasma half-life was 5.16 h. It has been demonstrated that 54 h after DXM-PHO injection, DXM concentrations were lower than 0.1 mglml. Tritiated dexamethasone was also administered twice to an another young bull for metabolite investigation. The elapsed time required to recover, in plasma, half of the radioactivity injected was 8.8 h. Radioactivity recovery in the urine reached 36.4% and 22.6% for the first and the second injections respectively. [less ▲]

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See detailOn the characterization of some terpenes from Renealmia alpinia Rott. (Maas) oleoresin.
Lognay, Georges ULg; Marlier, M.; Severin, M. et al

in Flavour and Fragrance Journal (1991), 6(1),

Detailed reference viewed: 23 (2 ULg)