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Silica Gel Column (silica + gel_column)

Distribution by Scientific Domains
Chemistry75%

Terms modified by Silica Gel Column

  • silica gel column chromatography
    		•

    Selected Abstracts

    Insecticidal activities of secondary metabolites of endophytic Pencillium sp. in Derris elliptica Benth

    JOURNAL OF APPLIED ENTOMOLOGY, Issue 8 2005
    M. Y. Hu
    Abstract:, A strain of endophytic Pencillium sp., which might produce rotenone or its analogues and showed bioactivity against aphids, was isolated from the fresh roots of Derris elliptica Benth. A total of 12 fractions, isolated from the chloroform extract of endophytic Pencillium sp. mycelia by silica gel column, were tested by bioassay and high-performance liquid chromatography (HPLC), and the more bioactive fractions were found to be D, E and J. Against the adult turnip aphid, Lipaphis erysimi, by dipping at a concentration of 1 mg/ml, the corrected mortalities of fraction D, E and J were 57.68, 63.28 and 69.74% after 48 h of treatment respectively. The three fractions also showed strong antifeeding activity against third instar larvae of Plutella xylostella in a laboratory bioassay. One absorption peak was detected in the HPLC picture of fraction D, it had a similar retention time as that of rotenone, and the chemical constituent, related to the absoption peak, had the same ultraviolet absorption picture as that of rotenone. Then it could be further concluded that the bioactive compounds in the fraction D could be rotenone or its analogous compounds. [source]

    IDENTIFICATION OF PROCYANIDIN A2 AS POLYPHENOL OXIDASE SUBSTRATE IN PERICARP TISSUES OF LITCHI FRUIT

    JOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2007
    JIAN SUN
    ABSTRACT Postharvest browning of litchi fruit results in short shelf life and reduced commercial value. Experiments were conducted to separate, purify and identify polyphenol oxidase (PPO ) substrates that cause litchi fruit to brown. PPO and its substrate were extracted from the pericarp tissues of litchi fruit. The litchi PPO substrate was purified using polyamide column, silica gel column and Sephadex LH-20 column chromatography. The browning substrate was selected by a 0.5% FeCl3 solution and then identified using a partially purified litchi PPO. Analyses of ultraviolet spectrometry, nuclear magnetic resonance and electrospray ionization mass spectrometry indicated that the PPO substrate was procyanidin A2. The substrate can be oxidized to , -quinones by litchi PPO and then form brown-colored by-products, resulting in pericarp browning of harvested litchi fruit. [source]

    Analyses of Glycolipids in Clove, Red Pepper, and Nutmeg by High-Performance Liquid Chromatography

    JOURNAL OF FOOD SCIENCE, Issue 6 2000
    H. Suzuki
    ABSTRACT: To determine the existence of glycolipids (neutral glycosphingolipid and glycoglycerolipid) in clove, red pepper, and nutmeg, we performed silica gel chromatography and high-performance liquid chromatography (HPLC) using an Aquasil-SS column and a C8 -reversed-phase silica gel column. HPLC (Aquasil-SS column) with a UV absorption detector was used to analyze neutral glycosphingolipid. These chromatograms showed two typical peaks in clove lipids. UV-HPLC (C8 -reversed phase silica gel column) was also used to analyze glycoglycerolipid. The chromatograms indicated a small peak in clove lipids. Moreover, we observed the same two peaks in the glycolipid fraction of clove lipid when we used HPLC (Aquasil-SS column) with a differential refractometer detector. These results suggest that clove may contain new and plural neutral glycosphingolipids. [source]

    Chiral separation of the ,2 -sympathomimetic fenoterol by HPLC and capillary zone electrophoresis for pharmacokinetic studies

    BIOMEDICAL CHROMATOGRAPHY, Issue 10 2010
    Thomas Ullrich
    Abstract The development of methods for the separation of the enantiomers of fenoterol by chiral HPLC and capillary zone electrophoresis (CZE) is described. For the HPLC separation precolumn fluorescence derivatization with naphthyl isocyanate was applied. The resulting urea derivatives were resolved on a cellulose tris(3,5-dimethylphenylcarbamate)-coated silica gel column employing a column switching procedure. Detection was carried out fluorimetrically with a detection limit in the low ng/mL range. The method was adapted to the determination of fenoterol enantiomers in rat heart perfusates using liquid,liquid extraction. As an alternative a CE method was used for the direct separation of fenoterol enantiomers comparing different cyclodextrin derivatives as chiral selectors. Copyright © 2010 John Wiley & Sons, Ltd. [source]