Showing papers on "Thin-layer chromatography published in 1994"
Book•
01 Jan 1994
TL;DR: Culture based tests culture and inoculation methods pigment enhancing media growth with inhibitory compounds carbon and nitrogen source assimiliation enzymatic activity on solid media enzymatics activity of fungal extracts and broths miscellaneous tests molecular biology methods protein electrophoresis DNA molecular biology chromatographic methods thin layer Chromatography of secondary metabolites high performance liquid chromatography UVNIS spectroscopy isolation and purification of secondary metabolism assessing biological activity.
Abstract: Culture based tests culture and inoculation methods pigment enhancing media growth with inhibitory compounds carbon and nitrogen source assimiliation enzymatic activity on solid media enzymatic activity of fungal extracts and broths miscellaneous tests molecular biology methods protein electrophoresis DNA molecular biology chromatographic methods thin layer Chromatography of secondary metabolites high performance liquid chromatography UVNIS spectroscopy isolation and purification of secondary metabolites assessing biological activity.
191 citations
TL;DR: Glycosphingolipids are well suited for analysis by thin-layer chromatography (TLC), which is useful for monitoring purification, for qualitative and quantitative determination of expression in normal and pathological tissues, for partial structural analysis, and for detecting biological activities.
Abstract: Publisher Summary Glycosphingolipids are well suited for analysis by thin-layer chromatography (TLC), which is useful for monitoring purification, for qualitative and quantitative determination of expression in normal and pathological tissues, for partial structural analysis, and for detecting biological activities, including immunoreactivity and binding activity toward toxins, viruses, bacteria, and eukaryotic cells. Although quantitative TLC can be used to determine the concentration of resolved glycosphingolipid species, it is useful to estimate the total concentration of glycosphingolipid in a sample prior to or in association with TLC. Glycosphingolipid samples must first be freed of major contaminating lipids, proteins, and low molecular weight contaminants. The most widely used TLC developing solvents for glycosphingolipids are mixtures of chloroform, methanol, and water (or aqueous salts), because they form a single phase at a range of hydrophobicities well suited for glycosphingolipid resolution on silica gel TLC plates. Reversible stains are useful for preparative TLC. To improve recovery, the plate should not be allowed to dry thoroughly at any time after running. The simplest but least sensitive reversible staining method is to spray the TLC plate heavily with distilled water.
136 citations
TL;DR: An organic acid, isolated and purified from the root extract of an Indian medicinal plant sarsaparilla Hemidesmus indicus R. Br, possessed viper venom inhibitory activity and significantly antagonized vipers-induced lethal, haemorrhagic, coagulant and anticoagulants activity in experimental rodents.
108 citations
TL;DR: In this article, a new separation approach combining thin-layer chromatography and molecular imprinting was proposed, and the results showed that the obtained chiral separation factor α was 3.5.
Abstract: A new separation approach, combining thin-layer chromatography and molecular imprinting, is reported. Thin-layer chromatography plates were made based on the molecular imprinting technique. Rapid chiral separation of L- and D-phenylalanine anilide, chosen as model compounds, was shown. The obtained chiral separation factor α was 3.5. The separation of other compounds (anilide, dansyl, ester, and amide derivatives of amino acids) was testes on L-phenylalanine anilide and nonimprinted TLC plates
94 citations
TL;DR: The purified enzyme was stable in solutions containing detergent and glycerol and was insensitive to metal chelators, dithiothreitol, phenylmethylsulfonyl fluoride, and diisopropyl fluorophosphate, but was inactivated by heat (60 degrees C) and ZnCl2.
54 citations
TL;DR: Partition coefficients (Koc) between water and dissolved organic material (DOM) were measured for benzo(a)pyrene (BaP), 3,3′,4,4′-tetrachlorobiphenyl (TCBP) and 2,3,7,8-tritachlorodibenzo-p-dioxin (TCDD) as mentioned in this paper.
53 citations
TL;DR: Results obtained by analysis of TFA as triacylglycerols compared favourably with those obtained by using methyl esters, and the findings of the FTIR method were substantiated by applying argentation chromatography in combination with capillary gas chromatography to the same set of samples.
Abstract: Trans fatty acids (TFA) formed during biohydrogenation by ruminant animals were quantified in cows' milk fat by means of Fourier transform i.r. (FTIR) spectroscopy. When samples were analysed as the derived methyl esters, a spectral subtraction technique resulted in TFA values that were not biased by the unspecific absorption of intact triacylglycerols or influenced by the shape of the trans band. Austrian milk fat samples contained 20-50 g TFA/kg. Results obtained by analysis of TFA as triacylglycerols compared favourably with those obtained by using methyl esters. The findings of the FTIR method were further substantiated by applying argentation chromatography in combination with capillary gas chromatography to the same set of samples. Besides trans monoenoic acids, non-methylene interrupted cis, trans octadecadienoic acids contributed significantly to the total trans content. Two novel TFA, trans-11, cis-15 octadecadienoic and cis-9, trans-13 octadecadienoic acids, were identified in milk fat by means of their retention behaviour on argentation chromatography and gas chromatography as well as by an oxidative degradation procedure.
51 citations
TL;DR: In this paper, a method for the separation, identification and estimation of eight biogenic amines (histamine, cadaverine, putrescine, phenylethylamine, tyramine, tryptamine, spermidine and spermine) using silica gel TLC and spectrophotofluorometry is described.
43 citations
TL;DR: In vivo and in vitro studies of incorporation of radioactive precursors showed diminished cuticular hydrocarbon synthesis after NaTCA treatment, which enhanced the penetration and increased the lethality of a contact insecticide.
Abstract: A new approach to insect control--using sodium trichloroacetate (NaTCA) to inhibit synthesis of the hydrophobic cuticular lipids that protect insects from dehydration--was tested on Triatoma infestans. In vivo and in vitro studies of incorporation of radioactive precursors showed diminished cuticular hydrocarbon synthesis after NaTCA treatment. Thin layer chromatography and scanning electron microscopy showed disruption of the cuticular lipid layer of NaTCA-treated insects, which also have increased mortality and altered molting cycles. NaTCA treatment enhanced the penetration and increased the lethality of a contact insecticide.
40 citations
TL;DR: In this article, an ethanol extract of Achillea millefolium L. showed repelling properties against the Aedes aegypti L. showing that the most active compounds were the nitrogen containing compound stachydrine, carboxylic acids, caffeic, chlorogenic, and salicylic acids.
Abstract: An ethanol extract ofAchillea millefolium L. showed repelling properties against the mosquito,Aedes aegypti L. Prepared fractions from the extract contained several active compounds which were characterized by thin layer chromatography, high performance liquid chromatography, gas chromatography and mass spectroscopy. Of 35 compounds tested, the most active were the nitrogen containing compound stachydrine, the carboxylic acids, caffeic, chlorogenic, and salicylic acids, and the phenolic compound pyrocatechol. These substances are earlier reported to occur inA. millefolium with the exception of pyrocatechol. Some further substances with lower activity were characterized for the first time inA. millefolium, i.e., adenine, ferulic and mandelic acid, and the methyl esters of capryliclinolenic- and undecylenic acid.
38 citations
Book•
01 Jan 1994
TL;DR: Overview and Recent Developments in Solid-Phase Extraction for Separation of Lipid Classes.
Abstract: Overview and Recent Developments in Solid-Phase Extraction for Separation of Lipid Classes * Thin Layer Chromatography with Flame Ionization Detection * Capillary Ionization Detection * Capillary Gas Chromatography of Myocardial Cholesterol Oxides * Gas Liquid Chromatography of Neutral Lipids * GLC and HPLC of Neutral Glycerolipids * GLC and High-performance Liquid Chromatographic Analysis of Lipid Peroxidation Products * Quantitative Analysis of Lipids by HPLC with a Flame-Ionization Detector or an Evaporative Light-Scattering Dectector * HPLC Analysis of Lipids (Analysis of Fatty Acids and Their Derivatives by a Microcolumn HPLC System) * Chromatographic Analysis of Ether-Linked Glycerolipids, Including Platelet Activating Factor and Related Cell Mediators * Gas Chromatography - Mass Spectroscopic Detection of Plasmalogen Phospholipids in Mammalian Heart Quantitative Capillary Gas Chromatography Mass Spectroscopic Detection of Plasmalogen Phospholipids in Mammalian Heart * Quantitative Capillary Gas Chromatography - Mass Spectrometry of Lipids Using Stable Isotope Dilution Methods * Supercritical Fluid Chromatographic Analysis of Lipids.
TL;DR: A simple quantitative HPTLC method for the determination of sorbic acid, benzoic acid and dehydroacetic acid in beverages without extraction or cleanup is described in this article.
Abstract: A simple quantitative HPTLC method for the determination of sorbic acid, benzoic acid, and dehydroacetic acid in beverages without extraction or cleanup is described. Aliquots of samples and standards are chromatographed on preadsorbent silica gel or C-18 bonded silica gel plates containing fluorescent indicator, and the zones, which quench fluorescence, are compared by scanning densitometry. Recoveries of the acids from wine and juices spiked at 50–300 ppm averaged 98%, and the coefficient of variation of replicate analyses ranged from 2–5%. Commercial sodas containing unknown amounts sodium benzoate and iced teas containing potassium benzoate were analyzed by the method, and the tea analyses were validated by standard addition. The advantages of the TLC method relative to current HPLC and absorption spectrometric procedures are described.
TL;DR: In this article, normal phase high performance liquid chromatography and silica gel thin-layer chromatography with densitometry were applied for the separation and quantitative determination of the diterpene glycosides stevioside and rebaudioside A in the leaves of the plant Stevia rebaudiana Bertoni.
Abstract: Two similar methods, normal phase high performance liquid chromatography and silica gel thin-layer chromatography with densitometry, were applied for the separation and quantitative determination of the diterpene glycosides stevioside and rebaudioside A in the leaves of the plant Stevia rebaudiana Bertoni. Results were compared and found to be very close in all basic features: resolution, accuracy and reproducibility. Thin-layer chromatrography was found to be more suitable in case of phytochemical screening of large number of samples.
TL;DR: In this paper, a column chromatography method for separation of phenolic compounds from flaxseed using Sephadex LH-20, RP-8 and silica gel is described.
Abstract: A column chromatography method for separation of phenolic compounds from flaxseed using Sephadex LH-20, RP-8 and silica gel is described. TLC analysis proved that separated fractions contained numerous phenolic compounds. All fractions exhibited a maximum UV absorption between 270 and 290 nm. Additional shoulders were observed between 274 and 350 nm. These results imply that lignans and their derivatives are the main phenolic compounds present in flaxseed.
TL;DR: In this article, commercial baker's yeast was analysed for lipids by TLC and GC, and the results showed that the presence of squalene, zymosterol, ergosterol and lanosterol in non-saponifiable lipid was proved and the compounds were determined by GC.
TL;DR: In this article, a series of congeneric compounds were measured at pH 9.0 and 1.2 using a reversed-phase TLC system with acetone, methanol or acetonitrile as the organic modifier of the mobile phase and silicone DC 200 as the impregnating agent of the silica gel layer.
TL;DR: From the results it appears that it is worthwhile to have a limit test for the composition of quaternary ammonium antiseptics in pharmacopoeial monographs, the more so as the antibacterial activity depends on it.
TL;DR: In this article, a sample preparation technique is described that affords alkaloid fractions suitable for capillary GC or TLC determination, which includes the reduction of the Noxides with the oxygen absorbing resin Serdoxit and a clean-up with strong cation-exchange solid-phase columns If desired an enrichment of the alkaloids can be obtained.
TL;DR: In this article, a cellulose-aqueous α-cyclodextrin was investigated for chiral separations of tryptophan, methyltryptophans and fluorotryptophan by thin-layer and paper chromatography.
TL;DR: The aim of the present study was to investigate the ganglioside expression of the highly metastatic murine lymphoreticular tumour cell line MDAY-D2, and found the dis8alogangliosides GD1α was found in equal amounts compared to GD1a.
Abstract: The aim of the present study was to investigate the ganglioside expression of the highly metastatic murine lymphoreticular tumour cell line MDAY-D2. Cells were propagated under controlled pH conditions and oxygen supply in bioreactors of 1 and 7.5l volumes by repeated batch fermentation. Gangliosides were isolated from 2.7×1011 cells, purified by silica gel chromatography and separated into mono- and disialoganglioside fractions by preparative DEAE anion exchange high performance liquid chromatography. Individual gangliosides were obtained by preparative thin layer chromatography. Their structural features were established by immunostaining, fast atom bombardment and gas chromatography mass spectrometry. In addition to gangliosides of the GM1a-pathway (GM2, GM1a and GD1a) and GM1b (IV3Neu5Ac-GgOse4Cer) and GalNAc-GM1b of the GM1b-pathway, the dis8aloganglioside GD1α (IV3Neu5Ac, III6Neu5Ac-GgOse4Cer) was found in equal amounts compared to GD1a (IV3Neu5Ac, II3Neu5Ac-GgOse4Cer). All gangliosides were substituted with C24:0,24:1 and C16:0 fatty acids, sphingosine andN-acetylneuraminic acid as the sole sialic acid.
TL;DR: In this article, the separation of 1,1,3,3-tetramethylphenyl surfactants was investigated by reversed-phase liquid chromatography (RP-LC) using various supports.
TL;DR: Chloroform-methanol-water (120:85:22, v/v, 2 mM CaCl2) was the solvent of choice for multiple chromatography of ganglio-series polysialogangliosides from embryonic chicken brain.
TL;DR: This report is the first description of multiprotein acylation by a long chain unsaturated fatty acid and proposes that [3H] palmitoleic acid is attached to proteins via a thioester linkage.
TL;DR: In this paper, the authors present a thin layer chromatography approach for separating and analysis of cotton fibres dyed with reactive dyes, which are not true dye extracts but they are nonetheless amenable to separation and analysis by thin-layer chromatography.
Abstract: Enzymatic digestion of cotton fibres dyed with reactive dyes produces coloured solutions. These are not true dye extracts but they are nonetheless amenable to separation and analysis by thin layer chromatography.
TL;DR: Using amino-bonded HPTLC plates and solution of 52% acetonitrile in 100 mM Tris-HCl buffer as the mobile phase it is possible to separate all enzyme substrates and competitively formed drug analogues of PtA from the oxidized enzymatic product.
TL;DR: Nocardia autotrophica was grown in a medium containing ferulic acid and 14C-ferulic acid, labelled in various parts of a particle as a main carbon source, and a liberation of 14CO2 during cultivation was noticed.
Abstract: Nocardia autotrophica was grown in a medium containing ferulic acid and 14C-ferulic acid, labelled in various parts of a particle as a main carbon source. After incubation, the products were analyzed by thin layer, high performance liqid and gas chromatography and by IR and NMR spectra methods. The products detected were caffeic acid, catechol, coniferyl alcohol, eugenol, guaiacol, hydrocaffeic acid, isoeugenol, isoferulic acid, isovanillic acid, p-hydroxybenzoic acid, protocatechuic acid and aldehyde, vanillic acid, and vinylguaiacol. A liberation of 14CO2 during cultivation was noticed.
TL;DR: In this article, various chromatographic techniques for isolation and separation of highly esterified sucrose polyesters (SPE) of olive oil are described, including thin-layer chromatography, Iatroscan TLC flame-ionization detection (FID), and highperformance liquid chromatography (HPLC) on reversed-phase.
Abstract: Various chromatographic techniques for isolation and separation of highly esterified sucrose polyesters (SPE) of olive oil are described. High-performance size-exclusion chromatography was used to check the purity of the samples, particularly to show that SPE were free from unreacted fatty acid methyl esters. Thin-layer chromatography (TLC), Iatroscan TLC flame-ionization detection (FID) and highperformance liquid chromatography (HPLC) on reversed-phase were applied for separation of octa-, hepta- and hexaesters of sucrose. Pure fractions from the total mixture, obtained by column chromatography, were identified by infrared and nuclear magnetic resonance spectroscopy. When necessary, specific reactions were applied; particularly, silylation and lead acetate-dichlorofluorescein (in toluene) spray were used to ascertain the degee of esterification of sucrose. Finally, octa-, hepta- and hexaesters of sucrose were quantitated by silica column chromatography, TLC/FID and HPLC on reversed-phase.
Journal Article•
TL;DR: In this paper, nonactic acid, homononactic acid and their 2-diastereoisomers were isolated by thin-layer chromatography on silica gel and by high-performance liquid chromatography in a reversed phase from the fermentation broth ofStreptomyces griseus, and identified by 1H and 13C NMR spectroscopy.
Abstract: Nonactic acid, homononactic acid and their 2-diastereoisomers were isolated by thin-layer chromatography on silica gel and by high-performance liquid chromatography on a reversed phase from the fermentation broth ofStreptomyces griseus, and identified by1H and13C NMR spectroscopy.
TL;DR: A relatively simple and sensitive method to measure femtomole amounts of phosphatidic acid in cells achieving a 1000-fold increase in sensitivity compared to the most sensitive of the previously described methods.