Showing papers on "Thin-layer chromatography published in 1977"
TL;DR: When aerobically incubated with liver microsomes and NADPH, chloroform produces a stable adduct with cysteine as a nucleophilic trapping agent that was identified by thin layer chromatography, gas-liquid chromatography and combined gas chromatography-mass spectrometry as the reaction product of Cysteine with phosgene.
118 citations
TL;DR: The method is rapid and easy to use and is therefore suitable for checking the purity of derivatives during the preparation of chlorophylls and their derivatives.
93 citations
TL;DR: The overall method, involving tissues extraction, thin-layer chromatographic separation and assay has been evaluated using pure standards and biological samples and gives good reproducibility and almost complete recovery of lipids.
87 citations
TL;DR: Two dimensional TLC procedures suitable for complete resolution of mixtures of these compounds on a single plate were developed and were used to demonstrate conversion of [1-14C]-arachidonic acid to thromboxane B2 and prostaglandin E2 by human lung fibroblasts in tissue culture.
58 citations
TL;DR: Except for the first two epoxy compounds, labelled a and b, the oxygenated fatty acids are similar to the products formed by homolytic decomposition of linoleic acid hydroperoxide.
Abstract: Bitter-tasting phosphatidylcholines from hexane-defatted soybean flakes were chromatographically separable from ordinary soy phosphatidylcholines (SPC). The bitter-tasting SPC contain 32% oxygenated fatty acids in addition to palmitic, stearic, oleic, linoleic, and linolenic acids. Identification of these oxygenated acids was based on infrared, ultraviolet, proton nuclear magnetic resonance, and mass spectral characteristics of methyl ester derivatives which were separated and purified by column and thin layer chromatography. The fatty acid methyl esters identified were (a) 15, 16-epoxy-9, 12-octadecadienoate, (b) 12, 13-epoxy-9-octadecenoate, both with double bonds and epoxide groups predominantly ofcis configuration; (c) 13-oxo-9,11-and 9-oxo-10, 12-octadecadienoates; (d) 13-hydroxy-9, 11- and 9-hydroxy-10, 12-octadecadienoates; (e) 9, 10, 13-trihydroxy-11- and 9,12,13-trihydroxy-10-octadecenoates. In addition, trace amounts of (f) 11-hydroxy-9,10-epoxy-12-and 11-hydroxy-12,13-epoxy-9-octadecenoates; (g) 13-oxo-9-hydroxy-10-and 9-oxo-13-hydroxy-11-octadecenoates; (h) 9,10-dihydroxy-12- and 12, 13-dihydroxy-9-octadecenoates; and (i) 9,12,13-dihydroxyethoxy-10- and 9,10,13-dihydroxyethoxy-11-octadecenoates were indicated by mass spectrometry. Dihydroxyethoxy compounds (i) were possibly formed upon extraction of the SPC from flakes by 80% ethanol. Except for the first two epoxy compounds, labelled a and b, the oxygenated fatty acids are similar to the products formed by homolytic decomposition of linoleic acid hydroperoxide. The first two compounds with predominantlycis configuration may occur by action of fatty acid hydroperoxides on an unsaturated fatty acid.
56 citations
54 citations
TL;DR: Thin layer chromatography of the sulfates, and gas-liquid chromatography after oxidation and solvolysis, showed that the substances were pure and that the sulfate group was at the expected position.
53 citations
51 citations
TL;DR: A simple and reproducible method using the non-ionic resin, Amberlite XAD-7, for the isolation of bile acids from serum by a batch procedure is described, and extracts were suitable for gas liquid chromatography, thin layer Chromatography, and radioimmunoassay.
Abstract: A simple and reproducible method using the non-ionic resin, Amberlite XAD-7, for the isolation of bile acids from serum by a batch procedure is described. Recoveries were greater than 95% for the non-sulphated bile acids and greater than 70% for the sulphate esters of bile acids. By using 1 g of resin, recoveries were independent of the mass (0.1-5 mumol) of the bile acid present. Up to 35 samples a day can be extracted without requiring dedication of the operator. When serum extracts were analysed by the 3alpha-hydroxysteroid dehydrogenase procedure for estimation of bile acids, virtually all the background fluorescence was eliminated. These extracts were also suitable for gas liquid chromatography, thin layer chromatography, and radioimmunoassay.
46 citations
TL;DR: In this article, the soluble carbohydrate content of four defatted oilseed flours (cottonseed, soybean, peanut, and sunflower) was determined by using high pressure liquid chromatography.
Abstract: The soluble carbohydrate content of four defatted oilseed flours (cottonseed, soybean, peanut, and sun-flower) was determined by using high pressure liquid chromatography. The best method of separating the sugars from the other components of water extracted flour was found to be thin layer chromatography. Plates of Silica Gel H with a running solvent of iso-propanol-water-ehtyl acetate (54:26:20) gave good isolation of the sugars. The μ BONDAPAK/ Carbohydrate column was used to analyze the sugars. An eluting solvent of acetonitrile and water (75:25 and 72:28) at a flow rate of 1.5 ml/min gave the best resolution of the carbohydrates. The major carbohy-drates in the oilseed flours were glucose, sucrose, raffinose, and stachyose. Small amounts of trehalose and an unidentified disaccharide were found in the flour of sunflower.
45 citations
TL;DR: Th Thin layer chromatography (TLC) and selective solvent extraction demonstrated that the products of the reaction contained many substances with a fluorescent spectrum similar to those of lipofuscin pigments, illustrating that fluorescent substances were formed in a variety of reactions associated with the oxidation of unsaturated lipids.
Abstract: The formation of fluorescent products in the reaction of methyl linoleate hydroperoxide with glycine in aqueous emulsions correlated directly with the decrease in diene conjugation and the increase in thiobarbituric acid (TBA) reactive substances. These correlations also were reflected in the course of the oxidation of methyl linoleate in aqueous emulsions with glycine and indicated that glycine reacted with products of peroxide decomposition as opposed to intermediates of autoxidation in hydroperoxide formation. Thin layer chromatography (TLC) and selective solvent extraction demonstrated that the products of the reaction contained many substances with a fluorescent spectrum similar to those of lipofuscin pigments. When methyl esters of polyunsaturated fatty acids or other polyunsaturated lipids underwent oxidation adsorbed on silica gel particles, products with similar fluorescent spectral properties were formed illustrating that fluorescent substances were formed in a variety of reactions associated with the oxidation of unsaturated lipids.
TL;DR: Experiments with germ-free rats strongly suggest that the intestinal flora is not the (sole) site for the biosynthesis of C18-phytosphingosine.
TL;DR: The methods developed here are recommended for the isolation of products from DNA treated with other cross-linking agents.
Abstract: A procedure is reported for the isolation of cross-linked nucleosides from nitrous acid-treated calf thymus DNA. Cross-linked DNA was hydrolyzed enzymatically with deoxyribonuclease I and snake venom phosphodiesterase and fractionated on a DEAE-Sephadex column. After desalting, the fractions were characterized by ultraviolet spectroscopy, anion exchange high pressure liquid chromatography, gel filtration, and two dimensional thin layer chromatography. A cross-linked dinucleotide, and a series of oligonucleotides were isolated. The oligomers, which had resisted digestion by the above enzyme system, were digested to the nucleoside level by a spleen phosphodiesterase-alkaline phosphatase combination. A second cross-linked product was isolated from this mixture. The cross-linked nucleosides were less than 0.17% of the total nucleotides of the DNA. The methods developed here are recommended for the isolation of products from DNA treated with other cross-linking agents.
TL;DR: There were no differences in the recoveries of ganglioside sialic acid from silica gel G thin-layer chromatograms when they were sprayed with resorcinol reagent varying in normality between 3 and 10, but both the temperature at and the time for which the plates were heated after spraying did affect the recovers.
TL;DR: A classification system for 151 antibiotics exhibiting antitumor properties using thin layer chromatography and bioautography was developed based on mobility of the compounds in a solvent system using a certain adsorbent.
TL;DR: A thin-layer chromatography procedure has been devised for detecting histidine, histamine, histidyl peptides and related imidazole compounds using a unique fluorogenic reaction, in which the compounds are derivatized with fluorescamine, converted into different fluorescent products by heating in strong acid medium, and separated on silica gel plates with an appropriate solvent system.
TL;DR: A thin-layer chromatographic method is described in which tetracyclines are separated on a cellulose layer by development with aqueous solutions of certain salts, allowing ready detection without the necessity for treatment with any reagents.
TL;DR: It can be postulated that the “D” spot contains compounds formed by a chain termination addition reaction of free radicals derived from CCl 4 derived from trichloromethyl free radicals to fatty acid free radicals containing conjugated dienes.
TL;DR: All the preparations obtained proved to exert considerable antitumor effect against Ehrlich ascites carcinoma in mice by intraperitoneal administration.
Abstract: Accrding to the procedure of Osipow, sucrose was partially acylated with palmitic, stearic, hydnocarpic, and ricinoleic acids. In the similar manner, the selective esterification of trehalose was performed, using caprylic, lauric, myristic, and stearic acids. The ester compositions of the resulting preparations were preliminarilly analysed by means of thin-layer chromatography and gas chromatography, and the major components contained in them were tentatively assigned to the 6-monoesters of these disaccharides. All the preparations obtained proved to exert considerable antitumor effect against Ehrlich ascites carcinoma in mice by intraperitoneal administration.
TL;DR: An effective resolution of intact phosphatidylserines on the basis of unsaturation has been achieved by conventional argentation thin layer chromatography (TLC) following trifluoroacetylaction.
Abstract: An effective resolution of intact phosphatidylserines on the basis of unsaturation has been achieved by conventional argentation thin layer chromatography (TLC) following trifluoroacetylaction. The trifluoroacetamides are prepared by treatment with trifluoroacetic anhydride or N-methyl-bis-trifluoroacetamide. The acetamides are resolved with chloroform-methanol-water (65∶25∶4, v/v/v) on Silica Gel G containing 20% silver nitrate. Subfractions with 0–6 double bonds per molecule were obtained for the phosphatidylserines of pig and ox brain, pig erythrocytes, rat liver, and rabbit skeletal muscle. The preparation of trifluoroacetamides is also advantagenous for the silver ion fractionation of phosphatidylethanolamines. The method is applicable to metabolic studies of molecular species using radioactive precursors of neutral lipids, phosphorus, and nitrogenous bases.
TL;DR: Metabolites of 3-methylcholanthrene formed by rat liver microsomes were analyzed by high pressure liquid chromatography and suggest the formation of epoxides of 3,3,3-trichloropropene oxide other than the K-region oxide.
01 Jul 1977
TL;DR: A method using thin layer chromatography and ultraviolet spectrophotometry for isolation and quantitative determination of daidzein from biological specimens was developed and was found to be sensitive and specific and was used in this study for the observation of the metabolic fate of d aidzein in animals and human bodies.
Abstract: A method using thin layer chromatography and ultraviolet spectrophotometry for isolation and quantitative determination of daidzein from biological specimens was developed This method was found to be sensitive and specific and was used in this study for the observation of the metabolic fate of daidzein in animals and human bodies
TL;DR: The results suggest that methyl linoleate oxidizes about ten times faster than methyl oleate, but oleates hydroperoxides are formed in appreciable amounts, even in mixtures containing 87% methyl linoreate.
Abstract: The hydroperoxides in oxidized mixtures of methyl oleate and linoleate were reduced to the corresponding hydroxyesters, which were separated from unoxidized esters by thin layer chromatography on silica gel. The hydroxyesters from oleate and linoleate were converted to trimethylsilyl ethers and separated by gas chromatography on OV 225. The results suggest that methyl linoleate oxidizes about ten times faster than methyl oleate, but oleate hydroperoxides are formed in appreciable amounts, even in mixtures containing 87% methyl linoleate.