Showing results 1 to 20 of 35
  Assessment of lipoxygenase activity in seed extracts from 35 plant speciesFauconnier, Marie-Laure  ; ; et alin 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 ▲] Detailed reference viewed: 30 (9 ULg)Measurement of glucosinolates in rapeseeds.Wathelet, Jean-Paul ; ; et alin 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 ▲] Detailed reference viewed: 20 (1 ULg)Gas chromatography-mass spectrometry study of terpenoids produced by shoot cultures of Artemisia annua L.; Fauconnier, Marie-Laure ; et alPoster (1994, June 12) Detailed reference viewed: 15 (3 ULg)Improvement Of Enzymatic-Synthesis Yields Of Flavor Acetates - The Example Of The Isoamyl AcetateRazafindralambo, Hary ; Blecker, Christophe ; Lognay, Georges et alin 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 ▲] Detailed reference viewed: 74 (41 ULg)Detection 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 ; ; et alin 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 ▲] Detailed reference viewed: 73 (5 ULg)Essential oil production by Anthemis nobilis L. tissue culture.Fauconnier, Marie-Laure ; ; et alin 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 ▲] Detailed reference viewed: 156 (3 ULg)THE CERTIFIED TOTAL GLUCOSINOLATE CONTENT IN 3 RAPESEEDS (CRM-190, CRM-366 AND CRM-367)Wathelet, Jean-Paul ; ; et alin 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 ▲] Detailed reference viewed: 38 (1 ULg)CHARACTERIZATION OF 3 LABDANE DITERPENES FROM AFRAMOMUM-ALBOVIOLACEUM; ; Lognay, Georges et alin 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 ▲] Detailed reference viewed: 58 (2 ULg)BIOLOGICAL-ACTIVITY OF THE SHRUB BOSCIA-SENEGALENSIS (PERS) LAM EX-POIR (CAPPARACEAE) ON STORED GRAIN INSECTS; Lognay, Georges ; Haubruge, Eric et alin 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 ▲] Detailed reference viewed: 153 (10 ULg)Identification of elemental sulphur (S8) in Boscia senegalensis (Pers.) Lam ex Poir. leaves.Lognay, Georges ; ; et alin Bulletin des Recherches Agronomiques de Gembloux (1993), 28(4), Detailed reference viewed: 18 (4 ULg)Production of essential oil by in vitro culture of Anthemis nobilis L. and characterization by GC-MS.; Fauconnier, Marie-Laure ; et alPoster (1992, September 21) Detailed reference viewed: 15 (2 ULg)On the characterization of some terpenes from Renealmia alpinia Rott. (Maas) oleoresin.Lognay, Georges ; ; et alin Flavour and Fragrance Journal (1991), 6(1), Detailed reference viewed: 17 (2 ULg)Determination of total glucosinolate in rapeseed (colza). Activities of BCR-programme Community Bureau of Reference .Wathelet, Jean-Paul ; ; in GCIRC Bulletin (1990) Detailed reference viewed: 19 (1 ULg)Preparation of A Rapeseed Sample With A Certified Content In Total Glucosinolates (CRM 190)Wathelet, Jean-Paul ; ; et alin Revue Française des Corps Gras (1989), 36(7-8), The preparatton af one rapeseed with known content tn total glucosinolates (CRM 190) and the steps taken to confirm their homogeneity and stabtlity are described. Details are presented of the ... [more ▼] The preparatton af one rapeseed with known content tn total glucosinolates (CRM 190) and the steps taken to confirm their homogeneity and stabtlity are described. Details are presented of the collaborative exercice which led to the certification. lndicative values are given for the content of individual glucosinolates, amino acids, and fatty acids. [less ▲] Detailed reference viewed: 7 (1 ULg)Study Of The Lipids From Renealmia-Alpinia (Rott) MaasLognay, Georges ; ; Haubruge, Eric et alin Grasas Y Aceites (1989), 40(6), Detailed reference viewed: 42 (2 ULg)Contribution à l'étude de l'huile de Mil à chandelle (Pennisetum americanum L. Schum.).Lognay, Georges ; ; et alin Rivista Italiana delle Sostanze Grasse (1988), 65(4), Detailed reference viewed: 19 (1 ULg)Etudes de nouvelles ressources en matières grasses de l'Amazonie péruvienne. Investigations sur l'huile de umari (Poraqueiba sericea Tul.).Lognay, Georges ; ; et alin Bulletin des Recherches Agronomiques de Gembloux (1988), 23(3), 271-282 Detailed reference viewed: 4 (1 ULg)FAST ANALYSIS OF RAPESEED GLUCOSINOLATES BY NEAR-INFRARED REFLECTANCE SPECTROSCOPY; ; et al in Journal of the American Oil Chemists' Society [=JAOCS] (1988), 65(10), 1599-1600 Detailed reference viewed: 25 (3 ULg)RAPESEED REFERENCE MATERIALS FOR GLUCOSINOLATE ANALYSIS - DEVELOPMENT OF RAPESEED BCR RM-190 AND THE RESULTS OF THE INTERCOMPARISON OF METHODSWathelet, Jean-Paul ; ; et alin Fresenius Zeitschrift Fur Analytische Chemie (1988), 332(6), 689-693 Detailed reference viewed: 13 (1 ULg)COMPARISON BETWEEN 4 METHODS TO MEASURE GLUCOSINOLATES IN RAPESEEDSWathelet, Jean-Paul ; ; et alin Revue Française des Corps Gras (1988), 35(4), 177-179 Total glucosinolate content in rapeseeds cultivated in France. Germany. Denmark, United Kingdom and Belgium has been determined by high performance liquid chromatography (HPLC), gas liquid chromatography ... [more ▼] Total glucosinolate content in rapeseeds cultivated in France. Germany. Denmark, United Kingdom and Belgium has been determined by high performance liquid chromatography (HPLC), gas liquid chromatography (GLC),measurement of glucose released by myrosinase and Pd glucosinolate complex after purification on an ion exchange column. Methods are well correlated. Glucose method and HPLC give similar results r: O.995, bias: O.055 µM/gr). ln most cases. GLC results are lower than HPLC (r: O.995, bias: - 2.482 µM/gr). Palladium method gives systematically higher results than HPLC (t: 0.99O, bias: 6.763 µM/gr). [less ▲] Detailed reference viewed: 54 (3 ULg)
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