Aid Of Thin-layer Chromatography Research Articles

Comparison between waste frying oil and paraffin as carbon source in the production of biodemulsifier by Dietzia sp. S-JS-1

In order to lower the production cost, waste frying oils were used in the biosynthesis of demulsifier by Dietzia sp. S-JS-1, which was isolated from petroleum contaminated soil. After 7 days of cultivation, the biomass concentration of the most suitable waste frying oil (WFO II) culture reached 3.78 g/L, which was 2.4 times the concentration of paraffin culture. The biodemulsifier produced with WFO II culture broke the emulsions more efficiently than that produced with paraffin culture, given the same volume ratio of carbon source in the culture medium and the same cultivation conditions. It achieved 88.3% of oil separation ratio in W/O emulsion and 76.4% of water separation ratio in O/W emulsion within 5 h. With the aid of thin layer chromatography (TLC) and Fourier transform infrared (FTIR) spectrometry, biodemulsifiers produced from both paraffin and WFO II were identified as a mixture of lipopeptide homologues. The subtle variation in the distribution of these homologues and high biomass concentration of WFO II cultures may account for the afore-mentioned good demulsification performance.

Effects of chromatographic fractions of <i>Euphorbia hirta</i> on the rat serum biochemistry

The effects of the chromatographic fractions of Euphorbia hirta Linn on the serum biochemical parameters in rats were investigated. The ethanolic extract of this plant was subjected to chromatographic separation using the vacuum liquid chromatographic technique, a modified form of classical column chromatography. With the aid of thin layer chromatography, six fractions of this plant were obtained and were administered to rats in graded doses of 400mg/kg, 800mg/kg and 1600mg/kg orally for fourteen days. Some fractions of this plant caused significant increase in the levels of total protein, albumin, globulin, alanine aminotransferase (ALT), alkaline phosphatase (ALP), aspartate aminotransferase (AST), total bilirubin, creatinine, and blood urea nitrogen (BUN). Some fractions also caused significant decrease in the level of conjugated bilirubin. The result from this study thus showed that some chromatographic fractions of Euphorbia hirta have potentially deleterious effects on the serum chemistry of rats; therefore caution should be exercised in the use of Euphorbia hirta as medicinal plant. It also means that the presence of this plant in the pasture could serve as a source of toxicosis to grazing animals. Keywords: E.hirta, chromatographic fractions, serum biochemistry, rats, toxicity African Journal of Biomedical Research Vol. 8(3) 2005: 185-189

Chiral Separations of Ibuprofen and Propranolol by TLC. A Study of the Mechanism and Thermodynamics of Retention

In contrast with gas and column liquid chromatography, both of which enable very efficient separation of enantiomers, thin‐layer chromatography (TLC) has never proved particularly successful in the same field. This can be regarded as puzzling because although the performance of TLC is substantially lower than that of the instrumental modes of chromatography, it still seems efficient enough to ensure even difficult separations of pairs of analytes. There is a steady demand for simple, inexpensive, and successful chiral separations, preferably executed with the aid of TLC. The best proof of this is a few documented and promising attempts reported by reliable laboratories in developing countries. Some of these reports, however, describe experiments performed with glass plates coated in the laboratory, which gives rise to questions regarding the accuracy and repeatability of the results obtained. Similar concerns are evoked by traditional visualization of the outcome of a separation by use of dyeing agents, rather than by densitometry (which furnishes concentration profiles of the bands and the possibility of in‐situ identification also). In this study, we have repeated chiral separations of two widely used drugs, ibuprofen and propranolol, adapting working conditions reported elsewhere to a system based on standardized and commercially available chromatographic plates. We also performed detection and identification on the developed chromatograms by means of densitometry. In our experiments with the modified chromatographic procedures, the results obtained proved at least as good as those reported in the original papers and occasionally somewhat better. For both ibuprofen and propranolol, preliminary thermodynamic evaluation of the standard chemical potentials of adsorption (Δμa) for each of the two enantiomers considered was also performed. The results obtained look promising and realistic; it seems that adsorption TLC can be used in the future for thermodynamic assessment of the racemization process.

Preparation and Characterization of Acid Hydrolysis Products of the Tomato Glycoalkaloid α-Tomatine

As part of an effort to define the biological roles of carbohydrate groups of the tomato glycoalkaloid α-tomatine in plants and animals, experiments were carried out to optimize the acid hydrolysis of the tetrasaccharide side chain of α-tomatine to products with three, two, one, and zero sugar groups. This was accomplished by following the time course for hydrolysis in 1 N HCl at 100 °C, isolating the hydrolysis products by chromatography on an aluminum oxide column, and determining the number and nature of hydrolysis products, including free sugars, with the aid of thin-layer chromatography and gas chromatography/mass spectrometry of alditol acetate sugar derivatives. The results show that a 20-min hydrolysis time appears useful for the formation of a mixture of the monosaccharide δ-tomatine, the disaccharide γ-tomatine, and the trisaccharide β1-tomatine. Efforts to isolate the other possible trisaccharide, β2-tomatine, were unsuccessful, apparently because xylose is degraded during the hydrolysis. A 70-...

Herpetomonas megaseliae: Effect of lipopolysaccharide on cell-surface anionogenic groups

Surface anionic groups ofHerpetomonas megaseliae, untreated or treated with lipopolysaccharides (LPS), were analyzed by cell electrophoresis and cytochemistry as well as by identification of sialic acid residues with the aid of thin-layer chromatography. LPS treatment of the trypanosomatids caused a marked decrease in the negative surface charge, as well as in binding to the cell surface of cationized ferritin, colloidal iron hydroxide, and Sendai virus particles. Incubation of LPS-treated and untreated flagellates with neuraminidase resulted in decrease of their mobility to the negative pole. The foregoing findings suggest that sialic acid residues are the major anionogenic groups exposed on the surface of this protozoon. Treatment with LPS markedly alters the nature and number of these residues. OnlyN-acetylneuraminic acid can be detected on untreated flagellates, whereasN-acetyl andN-glycolylneuraminic acid derivatives are found on the organisms exposed to LPS.

Maya blue: its presence in cuban colonial wall paintings

AbstractA blue pigment frequently found in Cuban colonial decorative wall paintings from about 1750 to 1860 has been identified with the aid of thin-layer chromatography, IR spectrometry, X-ray diffraction, thermal analysis, scanning electron microscopy and X-ray microanalysis as ‘Maya blue’. This is the first reported occurrence of Maya blue from a period after the conquest and in a non-Mayan cultural area.

微生物の化学変換に関する研究 ＸＸＩ 水‐有機溶媒系における固定化菌体のステロイド１６α‐ヒドロキシル化

The cells of Streptoinyces roseochromogenes NRRL-B-1233 were immobilized in photo-crosslinked resin, 2, 2-bis[4-[methacroyloxypoly (oxyethylene)]phenyl]propane(BPE-30). The immobilized microorganism catalyzed the transformation of dehydroepiandrosterone (DHEA) to 16 ahydroxyDHEA. The reaction was followed with the aid of thin-layer chromatography and gas chromatography. The original activity of the free cells was found to be retained about 100% after immobilization. The DHEA-16 α-hydroxylase activity of the entrapped cells in a 5 to 10% dimethyl sulfoxide system was approximately 40 to 80% higher than the original activity of the free cells. The entrapped cells showed maximal steroid 16 a-hydroxylase activity at 4.1 × 10-4mol·dm-4 DHEA. However, at higher concentrations a weak but signi ficant substrate inhibition appeared. The stability of the steroid 16 a-hydroxylase activity of the cells over repeated reactions was greatly improved by immobilization. These results strongly indicate the usefulness of the BPE-30 hydrophilic resin in iffniobilization of S. roseochromo genes having steroid 16 cr-hydroxylation activity.

Methylation of DNA in target and non‐target organs of the rat with methylbenzylnitrosamine and dimethylnitrosamine

The sites of labelling of DNA with [14C]methyl groups from methylbenzylnitrosamine and dimethylnitrosamine were studied in rat oesophageal epithelium and liver. All four combinations of tissue and carcinogen were studied. Tissues were labelled in vitro and the DNA contained therein purified and hydrolysed (pH 1, 37 degrees C) to free purines and apurinic acid. Quantitative analysis was performed with the aid of thin-layer chromatography. The apurinic acid and 7-methylguanine fractions were found to be extensively labelled. Smaller amounts of radioactivity were found in O6-methylguanine and some of the methylated adenines. The same carcinogen produced different patterns of labelling is oesophageal and liver DNA. The proportion of O6-methylguanine to 7-methylguanine was higher when the methylating agent was a carcinogen specific for the organ.

Steroid transformation by activated living immobilized Arthrobacter simplex cells

AbstractA preparation of living Arthrobacter simplex cells immobilized in polyacrylamide gel, which showed steroid‐Δ1‐dehydrogenase activity, was studied. The entrapped microorganisms catalyzed the transformation of cortisol to prednisolone and this reaction was followed spectrophotometrically or with the aid of thin layer chromatography (TLC) and high pressure liquid chromatography (HPLC). About 40% of the original activity found with free bacteria was retained after immobilization. The steroid dehydrogenase activity of polyacrylamide‐entrapped A. simplex could be raised to a minor extent in alcoholic solvents or by addition of a cofactor such as menadione. On incubation in various nutrient media, on the other hand, the activity could be increased considerablyl, usually 7–10 times. Possible causes for the observed increase in activity have been investigated, and microbial growth of the original entrapped microorganisms appears to be the major reason. Frozen activated preparations of immobilized A. simplex showed only a small loss of activity on storage for at least four months. A semicontinuous batch wise operation with immobilized A. simplex in different nutrient media was carried out. At the end of the experiment the steroid transformation capacity was 0.5 g steroid per day per g gel (wet weight).

Lipid pattern and fatty acid composition of human palatal oral epithelium

The lipid pattern and the fatty acid composition of human oral epithelium were studied qualitatively and quantitatively with the aid of thin-layer chromatography and gas-liquid chromatography. The material studied consisted of scrapings from the mucosa of the hard palate of nine cadavers and of three volunteers. Two methods for collecting the material were used: A) the epithelium was isolated by the removal of subepithelial connective tissue from the connective tissue side and B) the epithelium from the epithelial side was carefully scraped off. The lipid pattern of the epithelium was dominated by cholesterol (25 mol %) and phosphoglycerides (total 45 mol %), while triglycerides and free fatty acids constituted 10-15 mol % each. The fatty acid compostitions of the lipids were remarkably similar to each other, although the specific characteristics of each individual lipid were still noticeable. All lipids showed a large proportion of linoleic acid and a relatively small proportion of other polyunsatured fatty acids. In several respects the lipid pattern and the fatty acid composition of the epithelium were similar to those found in other ectodermal tissues, but they exhibited a number of differences from the corresponding pattern of the mesenchymal connective tissue.

Interaction of quinacrine mustard with calf thymus histone fractions.

1. Interactions of histone fractions with quinacrine mustard were investigated by fluorimetry and spectrophotometry and the results were interpreted with the aid of thinlayer chromatography. 2. Characteristic differences were found between the various histone fractions of calf thymus. The conditions that favoured histone conformational changes and aggregation, also favoured interaction between histones and the dye; low concentrations of SO(4) (2-) brought about more interaction than did Cl(-); urea, guanidinium and iodide ions were inhibitory to binding. 3. Changes in the physical state of all the quinacrine mustard-protein complexes occurred as a function of ionic strength and pH. The most salt-dependent interaction was found in the arginine-rich histone fraction. 4. The interaction of the calf thymus histone fractions with quinacrine mustard was compared with the interaction of bovine plasma albumin and protamine with quinacrine mustard. 5. The relationship between dye-binding and the aggregation of histone fractions was discussed.

Investigations on production and activity of Streptomyces antibiotics in soil: II. Activity of anthra quinone antibiotics in soil

Summary 1. Antibiotic production of a Streptomyces isolate (Str. diastatochromogenes) was examinedin sterilized and non-sterilized soil with the aid of thin layer chromatography and spectrophotometry. 2. In sterilized soils greater amounts of antibiotics were produced than in non-sterilized. Inboth media addition of organic materials generally stimulated antibiotic production more or less. Oat meal was especially effective in stimulating antibiotic production in sterilized as well as in non-sterilized soils. 3. Using the described detection method the soil adsorbed about 50% of the antibioticsK6 and C. 4. The molecules of the antibiotics were relatively stable against abiotic and biotic influences in soil. There was only gradual reduction in antibiotic concentration. This was accompanied by an accumulation of altered antibiotics, which were presumably identical with other antibiotics produced by the antagonist.

New aspects on reaction mechanisms in the formaldehyde histofluorescence method for monoamines.

The mechanisms of reactions underlying the fluorophore formation from indolylethylamines in the Falck-Hillarp histochemical formaldehyde method were investigated with the aid of thin layer chromatography and mass spectrometry of the fluorescent products formed in protein models and freeze-dried tissue. In the reaction of formaldehyde with tryptamine and 5-hydroxytryptamine, the main fluorophores formed were 3,4-dihydro-β-carboline and the 2-methyl-3,4-dihydro-β-carbolinium compound (from tryptamine), and 6-hydroxy-3,4-dihydro-β-carboline and the 2-methyl-6-hydroxy-3,4-dihydro-β-carbolinium compound (from 5-hydroxytryptamine). From these findings, it is concluded that the fluorophore formation in the Falck-Hillarp method proceeds as follows: In the first step of the reaction, the indolylethylamines react with formaldehyde to form low fluorescent 1,2,3,4-tetrahydro-β-carbolines. In a subsequent step, these products are converted to fluorophores in either of two ways: through an autoxidation to 3,4-dihydro-β-carbolines, or through a second, acid-catalyzed reaction with formaldehyde to yield 2-methyl-3,4-dihydro-β-carbolinium compounds. Experiments with radioactive tryptamine indicated that the two alternative fluorophore-forming pathways are of fairly equal importance. The latter of these fluorophore-forming reactions was not previously known, and the interesting properties and implications of this formaldehyde-induced and acid-catalyzed reaction are discussed.

Diagnosis of a Case of Acute Intermittent Porphyria with the Aid of Thin-Layer Chromatography—Thin-Layer Electrophoresis of Urine

Abstract δ-Aminolevulinic acid and porphobilinogen were identified in urine from a patient with acute intermittent porphyria on routine amino acid chromatography. The compounds were well and rapidly separated by a two-dimensional combination of high-voltage, thin-layer electrophoresis and chromatography. Both compounds gave a yellowish color with ninhydrin; the porphobilinogen gave a strong red color when Ehrlich’s reagent was then applied. Such a pattern has not been observed in any blood and urinary amino acid chromatograms from over 900 patients with other conditions, who were receiving a variety of drugs. We consider this a rapid, specific diagnostic aid in cases of acute intermittent porphyria.

Column separations designed precisely with the aid of thin-layer chromatography

The use of thin-layer silica gel as a column adsorbent has been investigated. IT was found that excellent separations of a plant wax could be obtained with quantitative recovery. Further, by the prior use of thin-layer chromatography on the same adsorbent it was possible to predict the course of the separation knowing only the elution volume of the first peak and the point at which solvents were changed. Thus thin-layer chromatography may be used to design column separations.

Digitalis saponins. II. Leaf saponins of Digitalis purpurea L.

As the leaf saponins of Digitalis purpurea L. two saponins, I and II, were detected on a paper chromatogram and isolated by column chromatography on alumina. With the aid of thin-layer chromatography I was found to be composed of two saponins, I-1 and I-2, while II to be a mixture of six (three pairs). I-1 and I-2 were obtained in pure state according to the Tschesche method and characterized, respectively, as tigogenin- and gitogenin-tetraglycosides both of which equally have one mole each of D-galactose and D-xylose and two moles of D-glucose as the sugar moieties. I-1, m.p. 284∼286°(decomp.), [α]28D-64.0°, was named desgalactotigonin and I-2, m.p. 252∼255°(decomp.), [α]25D-58.5°, F-gitonin. Three pairs of saponins in II were assumed to be penta-, hexa- and hepta-glycosides and each pair was presumed to consist of tigogenin- and gitogenin-glycosides both of which might have the same sugar composition.

Separation of acetylenic alcohols and diols with the aid of thin-layer chromatography on alumina

1. With the aid of thin-layer chromatography on alumina acetylenic alcohols and diols of various structures were separated. 2. The method was applied for the analysis of the products formed in the reaction of carbonyl compounds with acetylene.