Showing papers on "Thin-layer chromatography published in 1980"
TL;DR: Three distinct patterns of mycobacterial mycolates were produced by two-dimensional thin-layer chromatography, good examples of each pattern being the mycolate from Mycobacterium tuberculosis, Myc Cobacterium avium and MycOBacterium fortuitum.
653 citations
TL;DR: The mobile phases described permit separation of the six major phospholipids of amniotic fluid in one dimension with either conventional or high performance thin layer chromatography.
Abstract: The mobile phases described permit separation of the six major phospholipids of amniotic fluid in one dimension with either conventional or high performance thin layer chromatography. An example of this separation with an extract of amniotic fluid is given.
470 citations
TL;DR: In this paper, the relative rates of oxidation of methyl oleate, linoleate and linolenate in mixtures were ca. 1∶10.3∶21.6.
Abstract: The hydroperoxides in oxidized mixtures of methyl oleate, linoleate and linolenate were analyzed by reducing the hydroperoxides to the corresponding hydroxyesters and separating the hydroxyesters from the unoxidized esters by thin layer chromatography (TLC). The hydroxyesters from linolenate were separated from the other hydroxyesters by TLC on silver ion plates. The hydroxyesters were converted to TMS-hydroxy derivatives. The TMS-hydroxyoleate and TMS-hydroxylinoleate were separated by gas chromatography (GC), and all the TMS-derivatives were quantified by GC. The relative rates of oxidation of methyl oleate, linoleate and linolenate in mixtures were ca. 1∶10.3∶21.6. The hydroperoxides formed in the oxidation of soybean and olive oils were similar before and after randomization and similar to corresponding methyl ester mixtures.
228 citations
TL;DR: A modification of Marmur's method was used to isolate DNA, but difficulties in separating DNA from humic substances gave low yields and impure DNA.
Abstract: DNA has been isolated from the bacterial fraction of two soils. Numbers of bacteria, determined by fluorescence microscopy were 1.1 and 2.2·10 10 cells g −1 dry wt. The total amounts of bacterial DNA in these soils were 90 and 187 μg g −1 dry wt respectively. A modification of Marmur's method was used to isolate DNA, but difficulties in separating DNA from humic substances gave low yields and impure DNA. DNA could be partly separated from humic material in the presence of 8 m urea by ion-exchange chromatography on DEAE-Sepharose CL-6B. Final purification was obtained by chromatography on a hydroxyapatite column. When lowering the EDTA concentration in the saline-EDTA solution used for lysis, the amount of humic substances in the cell-free lysate after centrifugation was considerably decreased. The lysate could then be chromatographed directly on hydroxyapatite. Quantities up to 1.5 mg DNA high purity was isolated from 90 g wet soil (37 g dry wt). The isolated DNA was characterized by treatment with DNAse and absorption spectra. No uncommon bases were revealed by thin layer chromatography of the DNA hydrolysates. Melting curves of the isolated DNA showed a relatively broad melting profile, with half maximum hyperchromicity (T m ) near 90°C. Sedimentation coefficients determined by analytical ultracentrifugation showed that the isolated DNA had a high molecular weight, ranging from 2.3 to 10.1·10 5 daltons.
179 citations
TL;DR: Escherichia coli heat-stable enterotoxin derived from a strain pathogenic for man has been purified 13,000-fold to apparent homogeneity, suggesting the presence of disulfide bridges which are required for biological activity.
167 citations
TL;DR: Natural mixtures of bacterial menaquinones were separated according to the length and degree of saturation of the polyisoprenyl side-chain using ready made Merck RP-18F254 reverse phase thin-layer chromatography plates to provide a simple and rapid means of menaquinone characterization.
Abstract: Natural mixtures of bacterial menaquinones were separated according to the length and degree of saturation of the polyisoprenyl side-chain using ready made Merck RP-18F254 reverse phase thin-layer chromatography plates. The system described affords a simple and rapid means of menaquinone characterization.
141 citations
120 citations
TL;DR: The use of aqueous solutions of α-cyclodextrin as the mobile phase in thin layer chromatography (TLC) is described in this article, where a series of eighteen substituted benzoic acid compounds were chromatographed on polyamide thin layer sheets.
Abstract: The use of aqueous solutions of α-cyclodextrin as the mobile phase in thin layer chromatography (TLC) is described. A series of eighteen substituted benzoic acid compounds were chromatographed on polyamide thin layer sheets. The Rf values were dependent on the concentration of α-cyclodextrin in the mobile phase as well as the structure and size of the individual molecules. Possible advantages of this technique over those which use pure or mixed solvent systems as the mobile phase are discussed.
99 citations
01 Apr 1980-Zentralblatt für Bakteriologie: I. Abt. Originale C: Allgemeine, angewandte und ökologische Mikrobiologie
TL;DR: The formation of keto-gluconic acids appears to be a stable and reliable feature for the classification of acetic accid bacteria.
61 citations
TL;DR: It is suggested that a major site of protein methylation in human red blood cell membrane proteins is at aspartyl residues.
47 citations
TL;DR: In this paper, a reversed phase high performance thin layer chromatography has been evaluated for determination of octanol-water partition coefficients (P oct ) of organic chemicals and best correlations between log P oct and R M -values were obtained on a C 18 -bonded stationary phase using acetone-water or acetonitrile-water mixtures as eluting solvent.
TL;DR: A stepwise-development thin-layer-chromatographic technique for separating phosphatidylglycerol and phosphatIDylinositol in samples of amniotic fluid is described, correlated with the lecithin/sphingomyelin ratio and age of gestation in normal and abnormal pregnancies.
Abstract: We describe a stepwise-development thin-layer-chromatographic technique for separating phosphatidylglycerol and phosphatidylinositol in samples of amniotic fluid. Plates are prepared from silica gel G slurried in a 50 g/L ammonium sulfate solution. Phospholipid phosphorus determination is not needed. Phospholipid phosphorus determination is not needed. Phosphatidylglycerol and phosphatidylinositol, measured densitometrically, are expressed as ratios to the sphingomyelin present. These ratios are correlated with the lecithin/sphingomyelin ratio and age of gestation in normal and abnormal pregnancies.
TL;DR: In this paper, a novel type modification of circular thin-layer chromatography has been developed, in which the layer is tightly covered by a membrane, eliminating the vapour phase over the sorbent layer.
Abstract: A novel type modification of circular thin-layer chromatography has been developed, in which the layer is tightly covered by a membrane, eliminating the vapour phase over the sorbent layer. The developing solvent is pumped through the apparatus.
TL;DR: In this paper, high-performance liquid chromatography using an NH2-chemically bonded stationary phase, prepared from silica gel treated with benzene solutions containing 5-30% 3-aminopropyltriethoxysilane, was used to study low-molecular-weight aldehydes.
TL;DR: Partial glyceride mixtures, which include 1-monoglyceride, 1,3-diglyceride, free fatty acid and triglyceride, could be separated from each other on a 3% boric-acid-impregnated Chromarod S-II without any reconditioning procedure.
Abstract: Partial glyceride mixtures, which include 1-monoglyceride, 2-monoglyceride, free fatty acid, 1,2-diglyceride, 1,3-diglyceride and triglyceride, could be separated from each other on a 3% boric-acid-impregnated Chromarod S-II (silica gel sintered quartz rod) with either chloroform/acetone (96∶4, v/v) or chloroform/acetone/acetic acid (100∶1∶1, v/v) as the developing solvent mixtures. The components separated on the boric-acid-impregnated rod were automatically quantitated in a hydrogen flame ionization detector (Iatroscan). The relative responses of 1,2-diglyceride, 1,3-diglyceride, free fatty acid and triglyceride were slightly lower than theoretical responses based on weight percentage, whereas 1-monoglyceride and 2-monoglyceride showed slightly higher responses. These responses were converged within a maximal error of 5–10% (SD). Boric-acid-impregnated rods could be used repeatedly, ca. 5 times without any reconditioning procedure.
TL;DR: Using a new solvent (methyl acetate/n-propanol/chloroform/methanol/0.25% aqueous KCl) and high performance silica gel thin layer chromatographic plates, all common gangliosides found in brain can be easily separated with 1 hr.
Abstract: Using a new solvent (methyl acetate/n-propanol/chloroform/methanol/0.25% aqueous KCl, 25∶20∶20∶20∶17, v/v) and high performance silica gel thin layer chromatographic plates, all common gangliosides found in brain can be easily separated with 1 hr. This system is reproducible and “tailing” is negligible compared with previous solvents. When such a system is applied to separate the gangliosides found during the development of the rat cerebellum, a considerable heterogeneity is observed. Data are presented (using rechromatography experiments, fractionation on DEAE-Sephadex, treatment with neuraminidase or alkaline medium and carbohydrate analysis) suggesting that the complex profiles obtained with this chromatographic system are not due to chromatographic artifacts but result from the high resolving power of the system. After separation by ion-exchange chromatography, 28 gangliosides can be detected.
TL;DR: A method is described for the microscale characterization of the oligosaccharides of glycosphinglolipids using high-performance cellulose thin-layer chromatography and autoradiofluorography to identify the as yet unidentified glycolipids of rat erythrocyte ghosts.
Abstract: A method is described for the microscale characterization of the oligosaccharides of glycosphinglolipids using high-performance cellulose thin-layer chromatography and autoradiofluorography. With this procedure the oligosaccharides of neutral glycosphingolipids as well as gangliosides were analyzed at an average detection of 10 pmol. The method was tested with the known glycolipds from the erythrocytes of man, sheep, rabbit and guinea pig. As a further application small quantities of the as yet unidentified glycolipids of rat erythrocyte ghosts were isolated and their oligosaccharides determined.
TL;DR: In this article, a living polymer and the polystyrylmagnesium bromide derived from it were treated with carbon dioxide (solid or gas) and obtained the highest yields of carboxylic acid.
Abstract: Polystyryllithium was prepared by anionic polymerization. This “living polymer” and the polystyrylmagnesium bromide derived from it were treated with carbon dioxide (solid or gas). The highest yields of carboxylic acid were obtained when solid carbon dioxide was used with polystyryllithium or by treatment of polystyrylmagnesium bromide with gaseous carbon dioxide. The products from the reaction of polystyryllithium with oxygen were polymeric ketone X, the alcohols IXa and IXb, and coupling products (e. g., XI). The various functionalized and unfunctionalized polystyrene products were isolated by chromatography on silica gel and were characterized by gel permeation chromatography (GPC), thin layer chromatography (TLC), and high-performance liquid chromatography (HPLC) in combination with chemical transformations.
TL;DR: The identification of 4-Chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography-mass spectrometry using deuterium labelled 4-chloro-indole -3-acid methyl esters as an internal standard as mentioned in this paper.
Abstract: 4-Chloroindole-3-acetic acid methyl ester was identified unequivocally in Lathyrus latifolius L., Vicia faba L. and Pisum sativum L. by thin layer chromatography, gas chromatography and mass spectrometry. The gas chromatographic system was able to separate underivatized chloroindole-3-acetic acid methyl ester isomers.
The quantitative determination of 4-chloroindole-3-acetic acid methyl ester in immature seeds of these three species was performed by gas chromatography – mass spectrometry using deuterium labelled 4-chloro-indole-3-acetic acid methyl ester as an internal standard. P. sativum contained approximately 25 mg kg-1, V. faba 1–2 mg kg-1 and L. latifolius 2 mg kg-1 dry weight.
TL;DR: In this paper, several kinds of seeds used as bird feed were extracted successively with hexane, ether and methanol, and the antioxidant fraction separated from it by thin layer chromatography showed excellent activity for lard and sardine oil.
Abstract: Several kinds of seeds used as bird feed were extracted successively with hexane, ether and methanol. In the antioxidant test with extracts, the ether extract from canary seeds showed the highest activity. The antioxidant fraction separated from it by thin layer chromatography showed excellent activity for lard and sardine oil. The effective components were identified by gas chromatography and gas chromatography-mass spectrometry of the hydrolyzed products as the esters of caffeic acid with cycloartenol, gramisterol, sitosterol and campesterol with the minor amounts of 24-methylenecycloartanol, obtusifoliol, brassicasterol and Δ7-stigmastenol.
TL;DR: In this article, it was shown that many separations so far possible only on C 18 -columns can be achieved with adsorption chromatography on buffered silica gel, which may be used as an alternative to reversed phase chromatography for polar solutes.
TL;DR: This chapter discusses thin-layer chromatography (TLC) of pteroylmonoglutamates and related compounds, and a single solvent system gives good separation of most of the more important derivatives.
Abstract: Publisher Summary This chapter discusses thin-layer chromatography (TLC) of pteroylmonoglutamates and related compounds. The naturally occurring pteroylmonoglutamates can be separated from each other and identified by TLC. A single solvent system— namely, 3.0% (w/v) NH 4 Cl— gives good separation of most of the more important derivatives. The separated folates can be detected on the TLC plates, either by their fluorescent properties or, if they are present in trace amounts, by the removal of the powder in sections from the plates followed by desorption and microbiological assay, using Lactobacillus casei . This technique is not suitable for the separation of folate polyglutamates, and where these forms exist, they must be converted to the corresponding folate monoglutamate by enzymic hydrolysis prior to their separation. The pteroylmonoglutamate standards containing 0.5% MET are applied in the minimum possible volume so that approximately 5 μg of each derivative are applied. Biological extracts are also applied in minimum volume to achieve a concentration greater than 50 μg of folate activity per sample. Where the levels of folates are low, thicker plates may be used and more sample applied or the sample may be lyophilized and resuspended prior to the application. The plates are developed in different solvents at room temperature, usually for 80-90 min.
TL;DR: In this paper, the chromatographic behavior of 38 peptides on layers of silanized silica gel alone and impregnated with anionic and cationic detergents has been investigated.
TL;DR: The chromatographic characteristics of 33 amino acids have been studied using soap thin-layer chromatography (TLC) and many interesting separations that cannot be effected by ion-exchange TLC have been performed.
TL;DR: In this paper, the relationship between fluorescence enhancement and the properties of spray reagents was investigated, using 5-dimethylamino-1-naphthalene-sulfondimethylamide(DNS-DMA) as a fluorescent compound.
Abstract: In a fluorescence-enhancing method by spraying with a viscous organic solvent in thin-layer chromatography(TLC), the relationship between fluorescence enhancement and the properties of spray reagents was investigated, using 5-dimethylamino-1-naphthalene-sulfondimethylamide(DNS-DMA) as a fluorescent compound. A stuitable reagent should have two properties of giving high fluorescence intensity to a fluorescent compound and good transmigration from an adsorbent to the reagent medium, i.e., having the large product of relative fluorescence quantum number(RFQN) in the reagent solution and Rf value of the fluorescnet compound in TLC using the reagent as a developing solvent. A mixture of Triton X-100 and chlofoform(2:8) showed the largest product for DNS-DMA, so that the mixture was expected to be the most suitable reagent, and DNS-amine fluorescences on a plate were enhanced about 100-fold practically. Standard curves for DNS-amines were linear in the range of 1 to 20 pmole per spot. The Triton X-100 ...