Showing papers on "Thin-layer chromatography published in 1983"
182 citations
TL;DR: The present findings indicate that human colonic tissue can convert [14C]-AA into lipoxygenase as well as cyclo-oxygen enzyme products and support the suggestion that lip oxygengenase products may have a role in inflammatory bowel disease.
Abstract: The human colon synthetises several prostanoids which may have a role in inflammatory bowel diseases. As lipoxygenase products of arachidonate metabolism have been implicated in inflammatory processes, we have now investigated the formation of both lipoxygenase and cyclo-oxygenase metabolites from [14C]-arachidonic acid [(14C]-AA) by human colonic tissue. Homogenates of human colonic mucosa were incubated with [14C]-AA and after extraction into diethyl ether, separated by thin layer chromatography using two solvent systems that allowed resolution of cyclo-oxygenase and lipoxygenase products. The predominant cyclo-oxygenase products, as identified by their chromatographic mobility, were PGE2 greater than PGF2 alpha greater than PGD2 greater than TXB2 greater than 6-keto-PGF1 alpha. The formation of these products was inhibited both by indomethacin (1-10 microM) and the dual pathway inhibitor, BW755C (1-30 microM). The predominant lipoxygenase products formed, which had the chromatographic mobility of 11-, 12-, 15-HETE (which ran together) were inhibited by BW755C (19 microM) but not by indomethacin (3 microM). Further resolution of this TLC band, performed using normal phase HPLC, indicated that both 12-HETE and 15-HETE were major lipoxygenase products formed by human colonic homogenate. The present findings indicate that human colonic tissue can convert [14C]-AA into lipoxygenase as well as cyclo-oxygenase products and support the suggestion that lipoxygenase products may have a role in inflammatory bowel disease.
175 citations
TL;DR: Up to 15 different spots, corresponding to as many alkali-labile gangliosides, can be recognized by this procedure and individually detected and quantified on the basis of their sialic acid content.
110 citations
76 citations
TL;DR: The 6-membered hydroperoxy cyclic peroxides are apparently formed by 1,4-addition of singlet oxygen to 9- and 13-hydroperoxides with trans, trans-conjugated diene systems as mentioned in this paper.
Abstract: Previous studies of lipid secondary oxidation products have been extended to 6-membered hydroperoxy cyclic peroxides from the singlet oxygenation of a mixture of 9- and 13-hydroperoxides from autoxidized methyl linoleate. The oxidation product was fractionated by silicic acid chromatography with diethyl ether/hexane mixtures, and selected fractions were separated by polar phase high performance liquid chromatography. Products characterized by thin layer chromatography, gas liquid chromatography, ultraviolet, infrared, nuclear magnetic resonance and mass spectrometry included: 6-membered cyclic peroxides (13-hydroperoxy-9,12-epidioxy-10- and 9-hydroperoxy-10,13-epidioxy-11-octadecenoates), dihydroperoxides (8,13- and 9,14-dihydroperoxyoctadecadienoates) and keto dienes (9- and 13-oxooctadecadienoates). The 6-membered hydroperoxy cyclic peroxides are apparently formed by 1,4-addition of singlet oxygen to 9- and 13-hydroperoxides withtrans, trans-conjugated diene systems. Thermal decomposition of the 6-membered hydroperoxy cyclic peroxides at 200 C produced methyl 9-oxononanoate and hexanal as the major volatiles. Other volatiles included 2-pentylfuran, pentane, 4-oxo-2-nonenal, methyl furanoctanoate and methyl 9,12-dioxo-10-dodecenoate.
68 citations
TL;DR: In this paper, a procedure was developed for routine relative quantitative analysis of each of the ten isomeric dimethylnaphthalenes in crude oils, which requires isolation of an alkylnaphthalene fraction by thin-layer chromatography on activated alumina plates, followed by fused-silica capillary gas chromatography analysis on OV-1 and OV 1701 phases.
62 citations
TL;DR: In this paper, the authors used Field Desorption (FDMS) and Fast Atom Bombardment (FAB) to identify arsenobetaine in the isolates of sole, lemon sole, flounder, dab, crab and shrimps.
60 citations
TL;DR: In this paper, a reaction scheme for the hydrothermal degradation of glucose and fructose was obtained from these results using thin layer chromatography with methylene chloride, tetrahydrofuran (THF), acetic acid −60∵20∶20 as a mobile phase.
Abstract: The hydrothermal degradation was examined using D-(U-14C) glucose and D-(U-14C) fructose. By thin layer chromatography with methylene chloride, tetrahydrofuran (THF), acetic acid −60∶20∶20 as a mobile phase it was, possible to separate and identify the carbohydrates and their reaction products, glyceraldehyde, dihydroxyacetone, methylglyoxal, glycolaldehyde, 5-hydroxymethylfurfural and furfural. Up to 99% of the initial activity was determined by scintillation counting of the TL-chromatograms. A reaction scheme for the hydrothermal degradation of glucose and fructose was obtained from these results.
58 citations
TL;DR: The authors showed that β-cyclodextrin polymer forms inclusion complexes with the antibiotic polymyxine, reducing its lipophilicity and its adsorption energy on silica gel.
52 citations
TL;DR: Analyse des alkylbenzenes dans des eaux usees domestiques, des detergents domestiques and des sediments is presented in this paper, where alkyls benzenes are analyzed in terms of their properties.
Abstract: Analyse des alkylbenzenes dans des eaux usees domestiques, des detergents domestiques et des sediments
45 citations
TL;DR: The proportion of the ether phospholipid to the total recoverable phospholipsid was highest in anaerobic digester sewage sludge and deeper subsurface freshwater sediment horizons, and the methane levels in the pore water reflects the recovery of the phytanyl glycerol ether lipid 'signature'.
TL;DR: The separation conditions for hydrolysates of triglycerides by lipase and their quantitative determination are discussed for a thin layer chromatography-flame ionization detector system utilizing internal standards.
Abstract: The separation conditions for hydrolysates of triglycerides by lipase and their quantitative determination are discussed for a thin layer chromatography-flame ionization detector system utilizing internal standards. The complete separation of glyceride hydrolysis mixtures (triolein 1,3-diolein, 1,2-diolein, 1-monoolein and oleic acid) was achieved on a 3% boric acid-impregnated Chromarod S-II by development with benzene/chloroform/acetic acid (70∶30∶2, v/v/v) (mobile phase A) or hexane/ ether/acetic acid (70∶30∶1, v/v/v) (mobile phase B). Mobile phase B had an advantage over mobile phase A in terms of free space to add internal standards for simultaneous quantitation and was employed.p-Hydroxybenzoic acid andp-carboethoxy benzyl alcohol, which appeared between 1,2-diolein and 1-moloolein, were adopted as the internal standards. The calibration curves relating internal standards to each glyceride were all approximated by the equations Y=aXb giving high correlations. The method was applied to hydrolysis of triolein by pancreatic lipase.
TL;DR: Some components of Scolopendra morsitans venom extract were characterized using disc gel electrophoresis and thin layer chromatography to show three slowly moving lipoprotein bands and the lipid components included phospholipids, cholesterol, free fatty acids, triglycerides, cholesterol esters and squalene.
TL;DR: The reduction in enzymatic hydrolysis of isolated fractions from the thermally oxidized oils indicates structural differences, related to formation of polar compounds and polymerization products.
Abstract: The hydrolysis of thermally oxidized sunflower oil by pancreatic lipase was studied in relation to chemical changes in the acylglycerols. Four classes of compounds (monomers, dimers, trimers and polymers) formed from the acylglycerols were separated from the heated oils by column chromatography on silica gel, and further verified by thin layer chromatography. Each fraction, after analyses for generaly properties, was subjected to a time course study of hydrolysis by pancreatic lipase over a 30-min period. After 70 hr of heating, the amount of hydrolysis for the acylglycerol dimers was only about half that of the monomers, and that for the trimers was, in turn, about one-third that of the monomers. The polymers were the least hydrolyzed and showed no further reaction after 5 min. The reduction in enzymatic hydrolysis of isolated fractions from the thermally oxidized oils indicates structural differences, related to formation of polar compounds and polymerization products. Adverse effects on animals from feeding these materials can be attributed partly to inhibition of hydrolysis resulting in less available energy.
TL;DR: Mass spectrometry demonstrated a novel ganglioside in guinea-pig small intestine and a novel sulphoglycolipid in mouse small intestine.
Abstract: Acidic glycolipids (gangliosides and glycolipid sulphates) were purified from non-glycolipid contaminants by silicic acid chromatography of their acetylated derivatives Acetylation converted gangliosides into non-polar neutral and weakly acidic derivatives These were separated from acetylated sulphate-containing glycolipids by chromatography on DEAE-cellulose The fractions thus isolated from small intestine of 7 different animals were analyzed by thin-layer chromatography This revealed a considerable species-related variation of both gangliosides and sulphoglycolipids Mass spectrometry demonstrated a novel ganglioside in guinea-pig small intestine and a novel sulphoglycolipid in mouse small intestine
TL;DR: In this paper, the characteristics of eight types of commercially available thin-layer plates pre-coated with non-polar chemically bonded phases are compared and compared with eight test compounds: Phthalate esters, aromatic acids, chlorophenols, chloroanilines and aminophenols were used as test compounds.
TL;DR: The cytotoxicity test was significantly more sensitive than thin-layer chromatography for the trichothecenes and should be useful for screening extracts from animal feedstuffs for the presence of unknown mycotoxins.
Abstract: Thirty-three standard mycotoxins were assayed by thin-layer chromatography and by cytotoxicity in HEp-2 and Chang cells. Various levels of detection were found. The cytotoxicity test was significantly more sensitive than thin-layer chromatography for the trichothecenes and should be useful for screening extracts from animal feedstuffs for the presence of unknown mycotoxins.
TL;DR: High-performance thin layer chromatography, the material needed to apply this method of analysis and its use at the IPSC and a general comparison between the classical TLC and the HPTLC are presented.
TL;DR: The lipid compositions of sheep and mouse erythrocytes and of rat liver and kidney were determined by the present method of thin-layer chromatography followed by densitometry.
TL;DR: In this article, the reproducibility of the results obtained by gas and thin-layer chromatography was compared and the main advantages and disadvantages of both methods for lipid analysis were discussed.
TL;DR: Results suggest that the carboxyl group is not an absolute requirement for substrate hydrolysis, and that peptides containing a C-terminal nitrobenzylamine are also cleaved by the enzyme.
TL;DR: Raman spectra have been obtained from trace amounts of propanetriol trinitrate, tetramethoxymethane tetranitrate, 1,3,5,trinitro-1, 3,5-triazacyclohexane and 2,4,6-trinitron-1-methylbenzene adsorbed on silica gel and on activated charcoal.
Abstract: Raman spectra have been obtained from trace amounts of propanetriol trinitrate, tetramethoxymethane tetranitrate, 1,3,5-trinitro-1,3,5-triazacyclohexane and 2,4,6-trinitro-1-methylbenzene adsorbed on silica gel and on activated charcoal. Detection limits for these nitro compounds lay between 1 and 10 μg on silica gel and between 20 and 40 ng on activated charcoal.