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Showing papers on "Thin-layer chromatography published in 1981"


Journal ArticleDOI
T C Pederson1, J S Siak1
TL;DR: The Salmonella mutation assay has been adapted to a number of experimental procedures used to characterize the chemical components and molecular mechanisms involved in the direct-acting mutagenicity of diesel particle extracts, and the mutagens were found to be unreactive towards purified DNA.
Abstract: The Salmonella mutation assay has been adapted to a number of experimental procedures used to characterize the chemical components and molecular mechanisms involved in the direct-acting mutagenicity of diesel particle extracts. The mutagens were found to be unreactive towards purified DNA. Mutagenic activity was decreased in nitroreductase-deficient bacteria and increased in the absence of oxygen, suggesting that bacterial enzymes active the mutagens. The extract was fractionated by thin layer chromatography using both normal and reverse phase silica gel plates. On normal silica plates, a separation was made between unsubstituted PAH, nitro-PAH and the more polar aromatic compounds. About a third of the mutagenic activity in the particle extract was recovered in fractions containing monosubstituted nitro-PAH compounds. The absorption spectra and reverse phase chromatographic properties indicate 1-nitropyrene is a predominant component but not the only mutagen in these fractions. The remaining activity was in the more polar fractions, and mutagenicity assays using anaerobic conditions and nitro-reductase-deficient bacteria suggest they contain other nitro-substituted compounds.

169 citations


Journal ArticleDOI
TL;DR: Results indicate that the activated amino acid residue of the polypeptide is COOH-terminal glycine.

123 citations


Journal ArticleDOI
TL;DR: Analysis of myocardial ethanol intermediary metabolism in isolated, perfused rabbit hearts and whole heart homogenates provides insight into potential biochemical mechanisms contributing to the triacylglyceride accumulation, decreased beta oxidation of fatty acids, and other lipid abnormalities typical of effects of ethanol on the heart.

121 citations


Journal ArticleDOI
Giovanni Lercker1, P. Capella1, L. S. Conte1, F. Ruini1, G. Giordani1 
01 Dec 1981-Lipids
TL;DR: In this article, the fatty acid constituents of the lipid fraction of royal jelly were characterized by thin layer chromatography of corresponding methyl esters, and the most common characteristic of the organic acids was that most contained 8 or 10 carbon atoms, whether saturated or unsaturated, linear or branched.
Abstract: This present work characterizes the fatty acid constituents of the lipid fraction of royal jelly. Among the organic acids found after fractionation by thin layer chromatography of the corresponding methyl esters, the following compounds were identified by combined GC-MS: saturated and unsaturated linear fatty acids, saturated and unsaturated linear and branched dicarboxylic acids, mono-and dihydroxy acids. The most common characteristic of the organic acids was that most contained 8 or 10 carbon atoms, whether saturated or unsaturated, linear or branched.

102 citations


Journal ArticleDOI
TL;DR: Partition coefficients in n-octanol-water have been determined for the naturally occurring and some synthetic α-amino acids using thin-layer chromatography in different solvent systems as discussed by the authors.

99 citations


Journal ArticleDOI
TL;DR: A sensitive, reliable, and economical method for the determination of 6 mycotoxins in mixed feeds is described and has been applied to a wide range of mixed feeds, including laboratory animal diets, and raw materials.
Abstract: A sensitive, reliable, and economical method for the determination of 6 mycotoxins in mixed feeds is described. The feed is extracted with chloroform-water and the extract is cleaned up by using a disposable Sep-Pak silica cartridge. The procedure requires less time (15 min from sample extraction to extract preparation) and less solvent (approximately one-tenth) compared with conventional methods and is suitable for a fast, economical screen. Additional cleanup procedures, involving dialysis or extraction into base, are described for samples containing high levels of interfering compounds. Thin layer chromatography (TLC) and high performance liquid chromatography (HPLC) with fluorescence detection are described for identification and estimation of mycotoxins. The method has been applied to a wide range of mixed feeds, including laboratory animal diets, and raw materials. The limit of detection is 1 microgram/kg for all mycotoxins measured by HPLC.

89 citations


Journal ArticleDOI
TL;DR: The purification of an angiogenic substance from the Walker 256 rat ascites tumor is reported which is mitogenic for fetal bovine aortic endothelial cells in culture and which also stimulates new blood vessel growth in vivo.

68 citations


Journal ArticleDOI
M. Verzele1, C. Dewaele1
TL;DR: In this paper, it is shown that metal traces in high-performance liquid chromatographic bonded-phase silica gel interfere with some separations, and a test for such activity, based on the chromatography of beer bitter acids, is described.

62 citations


Journal ArticleDOI
TL;DR: The data suggest an enzymatic transfer of methyl groups from S-adenosylmethionine to free fatty acids, and the absence of long lived intermediates.

59 citations


Journal ArticleDOI
TL;DR: There is regional metabolism of arachidonate to monohydroxy eicosanoids in the kidney and the renal cortex does not metabolize arachidonic acid through the lipoxygenase pathway.

50 citations


Journal ArticleDOI
TL;DR: The response an linearity were studied for about twenty different types of lipids in a quantitative thin-layer chromatographic system equipped with flame ionization detection (TLC-FID), which showed good linearity for most compounds.


Journal ArticleDOI
TL;DR: Nine solvent systems and three solid supports are evaluated for their efficiency in separating psilocybin, psilocin and other components of crude mushroom extracts by thin-layer chromatography.

Journal ArticleDOI
TL;DR: The ability of the enzymes used to degrade the appropriate substrate was confirmed by incubating each lipase with a mixture of phosphatidylcholine, phosph atidylethanolamine, phosphAtidylserine, and sphingomyelin for 15 min at 37 OC.

Journal ArticleDOI
01 Oct 1981-Lipids
TL;DR: The amount of α-tocopherolquinone in rat liver has been reinvestigated comparing a conventional procedure including saponification and thin layer chromatography followed by high peformance liquid chromatography with the direct HPLC analysis of a total lipid extract.
Abstract: The amount of α-tocopherolquinone in rat liver has been reinvestigated comparing (a) a conventional procedure including saponification and thin layer chromatography followed by high peformance liquid chromatography (HPLC), with (b) the direct HPLC analysis of a total lipid extract. Recovery of added α-tocopherolquinone was quantitative with both procedures. In contrast to a recent report of 124 nmol/g in rat liver, we found no more than 1–4 nmol/g by procedure a and less than 1 nmol/g by procedure b.


Journal ArticleDOI
H. M. Thiede1, Wolfgang Kehr1
TL;DR: An assay is described for the simultaneous determination of dopamine, noradrenaline, adrenaline, dopa, 3,4-dihydroxyphenylacetic acid, 2,3- dihydroxy-phenylglycol, and 3, 4-dhydroxymandelic acid in a small volume of blood plasma of man, rat, dog and rabbit.
Abstract: An assay is described for the simultaneous determination of dopamine, noradrenaline, adrenaline, dopa, 3,4-dihydroxyphenylacetic acid, 3,4-dihydroxyphenyl-ethanol, 3,4-dihydroxymandelic acid and 3,4-dihydroxy-phenylglycol, capable of detecting amounts in the femtomol range The assay is based on the O-methylation of the catechol moiety utilizing S-[3H-methyl]-adenosyl-l-methionine and a partially purified catechol-O-methyl transferase to form the various O-[3H-methyl]-catechol derivatives The O-[3H-methyl]-catechol derivatives are purified by thin layer chromatography, solvent partitions and/or ion exchange chromatography The assay was successfully applied to biological sample It was possible for the first time, to detect free 3,4-dihydroxy-phenylglycol, free 3,4-dihydroxyphenylethanol and 3,4-dihydroxymandelic acid in a small volume (25μl) of blood plasma of man, rat, dog and rabbit The conjoint measurement of catecholamines and their catechol metabolites in minute amounts of biological samples may contribute to a more detailed understanding of catecholamine metabolism in the peripheral and central nervous system


Journal ArticleDOI
TL;DR: Deoxynivalenol (3,7,15-trihydroxy-12,l3-epoxytrichothec-9-ene-8-one) was extracted from corn with methanol/water (80:20, v/v) and purified by liquid:liquid partitioning and by preparative high pressure liquid chromatography (HPLC) as discussed by the authors.
Abstract: Deoxynivalenol (3,7,15-trihydroxy-12,l3-epoxytrichothec-9-ene-8-one) was extracted from corn with methanol/water (80:20, v/v) and purified by liquid:liquid partitioning and by preparative high pressure liquid chromatography (HPLC). This procedure was used to prepare mg quantities of toxin from field-inoculated corn for reference standards. Analysis of the isolated deoxynivalenol by analytical HPLC, gas liquid chromatography (GLC) and gas liquid chromatography/mass spectroscopy (GLC/MS) indicated the presence of a second compound similar to deoxynivalenol. This compound comigrates with deoxynivalenol on thin layer chromatography plates in chloroform/methanol (90:10, v/v), but can be separated by HPLC on a reverse-phase C8 column with methanol/water (10:90, v/v). GC/MS of the compound and the trimethylsilyl ether derivative gave parent ions of m/e 280 and 424, respectively. These data and NMR data indicate that the compound is 3,15-dihydroxy-12,13-epoxytrichothec-9-ene-8-one, a previously unreported trichothecene.



Journal ArticleDOI
TL;DR: In this article, the trimsilyl derivatives from polymerised silicate anions in an eight-year-old cement paste have been fractionated by high pressure liquid chromatography (hplc) and the fractions examined by thin layer chromatography, mass spectrometry and infrared spectrometer.

Journal ArticleDOI
TL;DR: The detection limit of ecdysteroids on reversed-phase plates is 10- -7 g, using fluorescence quenching or vanillin-sulphuric acid spray as mentioned in this paper.

Journal ArticleDOI
TL;DR: In this article, the authors developed methods for the labeling of acetate and palmitic acid with the positron-emitting radionuclide,11C (T = 20.4 min).
Abstract: Methods have been developed for the labelling of acetate and palmitic acid with the positron-emitting radionuclide,11C (T=20.4 min). Labelling was achieved via carbonation of the appropriate alkyl magnesium bromide (methyl magnesium bromide or n-pentadecyl magnesium bromide) with11C-labelled carbon dioxide produced by the14N(p, α)11C nuclear reaction. The radiochemical yield and speed of each method of labelling are such that a radiochemically pure product is obtained in injectable form and in activity (>10 mCi) suitable for the study of myocardial metabolism by emission-computerised axial tomography. High pressure liquid chromatography and thin layer chromatography were used to assess the radiochemical purity of each radiopharmaceutical. The specific activity of11C-labelled acetate was estimated by an enzymic procedure to be greater than 0.5 Ci/μmole.

Journal ArticleDOI
TL;DR: Fishman et al. as mentioned in this paper proposed an open-ended photoacoustic spectroscopy cell for thin-layer chromatography and other applications, which has been used in a variety of applications.
Abstract: Analytical Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Open-ended photoacoustic spectroscopy cell for thin-layer chromatography and other applications Victor A. Fishman, and Allen J. Bard Anal. Chem., 1981, 53 (1), 102-105• DOI: 10.1021/ac00224a026 • Publication Date (Web): 01 May 2002 Downloaded from http://pubs.acs.org on February 13, 2009



Journal ArticleDOI
01 Jun 1981-Lipids
TL;DR: In this paper, a wide range of C20 unsaturated fatty acids were prepared by the hydrazine reduction of 20∶5-Δ5,8,11,14,17.
Abstract: The fatty acids of a refined and of a partially hydrogenated menhaden oil, iodine value (IV) 84.5, were separated into different classes (e.g., monoene, diene, including pentaene and hexaene) by thin layer chromatography (TLC) of their methoxy-bromomercuri-adducts (MBM). In the solvent system hexane: dioxane, the separation of fatty acids occurred according to the degree of unsaturation. No influence was exerted by either the geometry or the position of the ethylenic bonds. The effect of the various chain lengths (C14−C22) was to broaden the bands, but no overlap occurred among the chain lengths. A wide range of C20 unsaturated fatty acids were prepared by the hydrazine reduction of 20∶5-Δ5,8,11,14,17. These were separated into groups as MBM adducts and identified by comparison of their experimental and calculated equivalent chain lengths (ECL) in gas liquid chromatography (GLC) on SILAR-5CP and SILAR-7CP columns. This confirmed that GLC did not totally separate all groups of isomers of different degrees of unsaturation. The quantitative analysis of both refined and partially hydrogenated (IV-84.5) menhaden oils by GLC was effected by the recovery of the fatty acid methyl esters from the MBM adduct TLC bands with the addition of methyl heptadecanoate (17∶0) as an internal standard, followed by analysis of the different fractions on open-tubular columns coated with SILAR-5CP. For methylene- and nonmethylene-interrupted unsaturated acids, 100% recovery from the MBM adducts was achieved, but in the case of the conjugated dienes the maximal recovery was 70%.

Patent
16 Dec 1981
TL;DR: In this paper, the authors used thin layer chromatography and high pressure liquid chromatography to separate antibiotic A-4696 factors from Actinoplanes missouriensis strains under submerged aerobic conditions in a culture medium and isolated from the fermentation broth by absorption on an ion exchange resin and eluted therefrom at pH 10.5 with sodium hydroxide.
Abstract: Antibiotic A-4696 factors B1, B2, B3, C1a, C3, and E1 are isolated from antibiotic A-4696, the latter being produced by Actinoplanes missouriensis strains ATCC 31680, ATCC 31682, and ATCC 31683 under submerged aerobic conditions in a culture medium and isolated from the fermentation broth by absorption on an ion exchange resin and eluted therefrom at pH 10.5 with sodium hydroxide. The novel factors are separated by thin layer chromatography and high pressure liquid chromatography and have antimicrobial and growth promotant activity.

Journal ArticleDOI
TL;DR: Compounds separated on polyamide thin-layers and located in an appropriate manner can be introduced directly into the ion source of the mass spectrometer together with the chromatographic polyamide adsorbent and excellent mass spectra are obtained exhibiting low backgrounds.