Showing papers on "Thin-layer chromatography published in 1989"
TL;DR: For rapid and sensitive screening of lipid biochemical abnormalities of scaling skin disorders a sequential, one-dimensional high-performance thin-layer chromatographic method (HPTLC) has been developed, particularly suitable for the determination of minor amounts of cholesterol sulfate and other sterols.
103 citations
TL;DR: In this paper, the authors present des resultats des reactions quantitative de solubilisation de cyclodextrines par diverses bases. But they do not discuss the results of their experiments.
Abstract: Presentation des resultats des reactions quantitatives de solubilisation de cyclodextrines par diverses bases
80 citations
TL;DR: The radioactive products extracted from the pheromone glands and media by hexane revealed incorporation of radioactivity into a product exhibiting the same mobility as (Z)-11 hexadecenal, the main component of the phersomone of H. armigera.
78 citations
TL;DR: The isomers of eicosapentaenoic and docosahexaenoic acids in liver lipids probably resulted from desaturation and elongation of 18∶3 δ9c, 12c, 15t, a geometrical isomer of linolenic acid present in the heated dietary oil.
Abstract: Monotrans geometrical isomers of 20∶5 n−3 and 22∶6 n−3 were detected in liver lipid of rats fed heated linseed oil. The isomers were identified as being 20∶5 δ5c, 8c, 11c, 14c, 17t and 22∶6 δ4c, 7c, 10c, 13c, 16c, 19t. These fatty acids were isolated as methyl esters by preparative high-performance liquid chromatography (HPLC) on reversed phase columns followed by silver nitrate thin layer chromatography (AgNO3-TLC). The structures were identified using partial hydrazine reduction, AgNO3-TLC of the resulting monoenes, oxidative ozonolysis of each monoene band, and gas-liquid chromatography (GLC) of the resulting dimethyl esters and monomethyl esters. Fourier-transform-infrared spectrometry confirmed thetrans geometry in isolated 20∶5 and 22∶6 isomers. The isomers of eicosapentaenoic and docosahexaenoic acids in liver lipids probably resulted from desaturation and elongation of 18∶3 δ9c, 12c, 15t, a geometrical isomer of linolenic acid present in the heated dietary oil.
70 citations
TL;DR: This study demonstrates that a propionic acid, ammonium hydroxide, isoprophyl alcohol solution may be a useful ascending solvent mixture for this purpose of thin-layer chromatography in phosphoamino acid analysis.
65 citations
TL;DR: It is suggested that farnesylation of cysteine residues accounts for the well documented incorporation of mevalonic acid into mammalian cell proteins.
61 citations
Book•
01 Jan 1989
TL;DR: The main findings are determination of free and esterified carnitine and quantitative analysis of amino acid analysis by gas chromatography and the role of Na6(CO3)(SO4)2, Na2SO4 and Na2CO3 in the determination of carnitines.
Abstract: ENZYME ASSAYS: General procedures and buffers Fluorometric assays Spectrophotometric assays Radioisotope assays DIAGNOSTIC TESTS FOR METABOLIC DISORDERS SPECIMEN COLLECTION AND HANDLING: Urine spot tests Thin layer chromatography (TLC) Quantative amino acid analysis Organic acid analysis by gas chromatography Determination of free and esterified carnitine Appendix
54 citations
TL;DR: A new hydroxylated, very long-chain fatty acid has been isolated and characterized from the lipopolysaccharide of Rhizobium trifolii ANU 843 and appears to be the major structural feature of the lipid A of this organism.
53 citations
TL;DR: Methods for the screening of fungal cultures for toxic secondary metabolites are reviewed and a general method for the detection of Penicillium, Aspergillus, Fusarium, Alternaria and Cladosporium toxins is suggested.
Abstract: Methods for the screening of fungal cultures for toxic secondary metabolites are reviewed. Thin layer Chromatography (TLC) and high-performance liquid Chromatography (HPLC) are good general analytical methods for secondary metabolites in unpurified extracts. The combination of normal phase TLC using different chemical spray reagents with reversed phase HPLC, using alkylphenone retention indices and diode array detection, is a powerful technique for identifying the individual mycotoxins detected. The results of the screening methods are very dependent of the growth media and incubation conditions and a general method for the detection ofPenicillium, Aspergillus, Fusarium, Alternaria andCladosporium toxins is suggested.
49 citations
TL;DR: Human tracheobronchial mucin was isolated from lung mucosal gel by chromatography on Sepharose 4B in the presence of dissociating and reducing agents, and its thiol residues were carboxyamidomethylated with iodo[1(-14)C]acetamide.
46 citations
TL;DR: Results obtained from Penicillium, Aspergillus and Fusanum species have shown that each species produces 5 to 15 different biosynthetic families of secondaiy metabolites, indicating that good chromatography data may be sufficient to identify species in the three genera.
TL;DR: Etude par chromatographie sur couche mince, de ladsorption et la desorption du polystyrene sur la silice dans un melange toluene-tetrachloromethane.
Abstract: Etude par chromatographie sur couche mince, de l'adsorption et la desorption du polystyrene sur la silice dans un melange toluene-tetrachloromethane
TL;DR: In this article, the authors demonstrate des possibilites analytiques du couplage de la spectrometrie de masse a laser a la chromatographie en couche mince.
Abstract: Demonstration des possibilites analytiques du couplage de la spectrometrie de masse a laser a la chromatographie en couche mince. La technique a ete appliquee a la separation d'hydrocarbures aromatiques et de bases puriques
TL;DR: In this article, two methods for the detection and measurement of peramine, an alkaloid from endophyte-infected grasses with insect feeding deterrent activity, are described.
TL;DR: Analysis of skin surface lipids from 15 normal subjects indicates that the alkanes found on the surface of human skin are mixtures of a variety of petroleum distillation fractions that are acquired by direct contamination from the environment.
TL;DR: This optical resolution method for 2, 6-diaminopimelic acid (DAP) stereoisomers by high performance liquid chromatography (HPLC) made it possible to analyze quantitatively LL, DD, and meso-DAP compared with the previously reported methods of paper chromatography, thin-layer chromatography and HPLC.
Abstract: For the chemotaxonomy of actinomycetes, we describe the optical resolution method for 2, 6-diaminopimelic acid (DAP) stereoisomers by high performance liquid chromatography (HPLC) using 2, 3, 4, 6-tetra-O-acetyl- β-D-glucopyranosyl isothiocyanate (GITC). The analysis was applicable both to whole-cell preparations and to cell wall ones. This method made it possible to analyze quantitatively LL-, DD-, and meso-DAP, compared with the previously reported methods of paper chromatography, thin-layer chromatography and HPLC.
TL;DR: Identification and dosage de toute une serie de residus d'antibiotiques dans les reins ; comparaison avec la methode microbiologique as discussed by the authors.
Abstract: Identification et dosage de toute une serie de residus d'antibiotiques dans les reins ; comparaison avec la methode microbiologique
TL;DR: The distribution of lipid in various sites of the edible fillets of the blue mackerel was determined and the white muscle phospholipids included more polyunsaturated [cicosapentaenoic and docosahexaenoic (DHA)] acids than those of the dark muscle.
Abstract: The distribution of lipid in various sites of the edible fillets of the blue mackerel (Scomber australasicus) was determined. Specific details of the lipid composition of the dark and white muscles were provided by column and thin layer chromatography. Dark muscle contained 20% lipid whereas white muscle had only 4% lipid. However, white muscle lipid was relatively much higher in phospholipids; 19% vs 10% in dark muscle lipid. The major phospholipids were phosphatidylcholine, phosphatidyl ethanolamine, and sphingomyelin. These were distributed in similar proportions in both muscles, although the white muscle phospholipids included more polyunsaturated [cicosapentaenoic (EPA) and docosahexaenoic (DHA)] acids than those of the dark muscle.
TL;DR: A thin layer Chromatographic and high performance liquid chromatographic method for quantitation of gliotoxin from rice culture was developed and is described.
Abstract: Gliotoxin, a mycotoxin with antimicrobial and immunosuppressive capabilities, is produced by several genera of fungi including the pathogenic fungusAspergillus fumigatus. The ability of selected isolates ofA. fumigatus to produce gliotoxin on three different media was tested and a thin layer chromatographic and high performance liquid chromatographic method for quantitation of gliotoxin from rice culture was developed and is described. Rice cultures were extracted with chloroform and the resulting extract was partially purified by precipitation with petroleum ether and cleanup by gel permeation chromatography. Gliotoxin was detected by thin layer chromatography and quantitated by high performance liquid chromatography using a U.V. absorbance detector with a 254 nm filter and a mobile phase of methanol-water 43∶57 (V/V) with a flow rate of 2.0 ml/min. The retention time for gliotoxin was approximately 4.8 min. From rice samples spiked with gliotoxin concentrations of 0.67, 1.33, 2.67, 4.00 and 5.33μg/g the average recovery was 83.8%.
TL;DR: Differences were found in the mechanism of the process compared with the systems described by Yuasa et al.
Journal Article•
TL;DR: Two multimodal two-dimensional TLC procedures are described for the separation of taxol and cephalomannine from other natural products found in the bark of Taxus brevifolia as discussed by the authors.
Abstract: Two multimodal two dimensional TLC procedures are described for the separation of taxol and cephalomannine from other natural products found in the bark of Taxus brevifolia. For the first procedure, a cyano modified silica gel plate was developed in the first dimension in methylene chloride: hexane acetic acid (9:10:1) and in the second dimension in water: acetonitrile: methanol: tetrahydrofuran (8:5:7:0.1). For the second procedure, a diphenyl modified silica gel plate was developed in the first dimension in hexane: isopropanol: acetone (15:2:3) and in the second dimension in methanol: water (7:3). In both procedures, taxol was resolved from cephalomannine and at least another twenty compounds
TL;DR: In this paper, linear diglycerol was isolated from polymerized glycerol by acetonation, fractional distillation and regeneration, and the correlation of structure of the fatty acids in the mono-and diesters with surfactant properties is of interest.
Abstract: Fatty acid mono- and diesters of diglycerol constitute the major portion of commercial polyglycerol esters; hence, their composition influences the performance of the latter as emulsifiers. The correlation of structure of the fatty acids in the mono- and diesters with surfactant properties is of interest. Linear diglycerol was isolated from polymerized glycerol by acetonation, fractional distillation and regeneration. Diglycerol mono- and diesters of undecenoic, lauric, stearic, oleic and ricinoleic acids were prepared by reacting diglycerol and fatty acids in a refluxing mixture of acetonitrile-tetrahydrofuran (75:25) in the presence of p-toluenesulfonic acid and molecular sieves. Mono- and diesters were separated by silica gel column chromatography, and their purities were ascertained by thin layer chromatography and determination of saponification value. The structures were confirmed by periodic acid oxidation, chemical-ionization mass spectrometry and 13 C-NMR spectroscopy. Surfactant properties of the esters were determined. Monoesters showed higher ability in surface tension reduction, emulsification and foaming than the diesters. Short-chain fatty acid esters showed better surfactant properties than the long-chain fatty acid esters. The presence of a central double bond in the lipophilic part of the monoesters reduced emulsion stability. The presence of a hydroxy group in acyl chain retarded foaming and surface tension reducing power.
TL;DR: An HPLC method for the separation and analysis of arachidonic acid and eight phospholipid classes is described and there was a significant correlation between the radioactivity profiles obtained with the two chromatographic methods by linear regression analysis.
TL;DR: In vivo labeling of Escherichia coli JA200 pLC 11-8 resulted in 32P incorporation into enolase as demonstrated by immunoaffinity chromatography and electrophoresis followed by autoradiography and the identification of a labeled residue corresponding to phosphoserine.
TL;DR: The chiral selector 2 is synthesized from (all R)-1.2 and used as a copper(II) complex for the impregnation of RP 18-TLC plates.
TL;DR: The (S)-configuration was assigned to α-damascone and α-ionone, important flavour components in black tea, by enantioselective capillary gas chromatography using octakis(3-O-methyl-2,6-di-Opentyl)-γ-cyclodextrin as a chiral stationary phase as discussed by the authors.
28 Sep 1989
TL;DR: Mise en evidence et identification des trois principaux isomeres trans de l'acide octadecadienoique dans des huiles hydrogenees as mentioned in this paper.
Abstract: Mise en evidence et identification des trois principaux isomeres trans de l'acide octadecadienoique dans des huiles hydrogenees
TL;DR: The findings indicate that the general structure of this precursor is that of a phospholipid, specifically a plasmalogen—the exact structures of which remain to be determined.
Abstract: Fecapentaene-12 and fecapentaene-14 are genotoxic polyunsaturated ether-lipids produced by the colonic microflora in humans and pigs. Although the fecapentaenes have been extensively characterized, little is known about the nature of the precursors from which they are produced. We purified one form of these precursors from feces of an individual who excreted high levels of fecapentaene-12 and its precursors. Purification was carried out by a series of extractions and precipitation in organic solvents followed by silica and amine high performance liquid chromatography. The purified precursor had identical UV spectral characteristics as the fecapentaenes indicating that it contained the same ether-linked pentaenyl functional group. However, it was not mutagenic. The precursor was amphiphilic in nature, behaving like a synthetic “model” ether-phospholipid on silica and C18 thin layer chromatography. When incorporated into phosphatidylcholine micelles it could be hydrolyzedin vitro by a combination of lipase and phospholipase C to fecapentaene-12. Our findings indicate that the general structure of this precursor is that of a phospholipid, specifically a plasmalogen—the exact structures of which remain to be determined.