Showing papers on "Paper chromatography published in 1988"
TL;DR: The sensitivity of the RIA decreased with time if paper chromatography purified radioligands were used, but remained stable for 4 months if the HPLC purified compounds was used, even with storage at 4 degrees C.
34 citations
TL;DR: A combination of paper chromatography, ion-exchange and reversephase high performance liquid chromatography with post-column antitumor assay has been developed, which allows a specific identification of an ovine pineal factor which inhibits the growth of human melanoma cells in vitro.
Abstract: An in vitro human melanoma cell assay was used to work up the partial purification of (a) low molecular weight (MW) substance(s) from aqueous extracts of ovine pineal tissue shown to contain a growth-inhibiting activity. A combination of paper chromatography, ion-exchange and reversephase high performance liquid chromatography with post-column antitumor assay has been developed. This allows a specific identification of an ovine pineal factor (MW<500) which inhibits the growth of human melanoma cells in vitro. The substance was partially purified to about 1,000 times as compared to the IC100-value of the starting material (retentate5). The growth inhibition of human melanoma cells in culture was complete at a dose of 0.1 μg/ml of purified pineal factor(s). It was demonstrated that the activity of this pineal compound differs from some substances known to be present in the pineal, such as melatonin, serotonin, peridines and β-carbolines. The activity was not destroyed by treatment with proteolytic enzymes.
22 citations
TL;DR: Hypoxanthine-DNA glycosylase from E. coli has an obligatory requirement for Mg2+ and is totally inhibited in the presence of EDTA, and Co2+ can only partially replace Mg1+ while the enzyme is inhibited by hyp oxanthine which at 4 mM causes 85% inhibition.
18 citations
TL;DR: 2-Deoxyglucose was found to be an excellent non-metabolized analogue of D-glucOSE in oxidation experiments and could have some taxonomic applications.
Abstract: Extracellular D-glucose oxidation by 5 enterobacterial species was studied with the purpose of selecting conditions useful for taxonomic studies. Extracellular production of gluconate from 14C-glucose by bacterial cells was evidenced by DEAE-cellulose paper chromatography. Escherichia coli oxidized glucose only when pyrroloquinoline quinone (PQQ) was added, whereas Serratia marcescens, Yersinia frederiksenii, Erwinia cypripedii and Cedecea lapagei oxidized D-glucose without added PQQ. 2-Deoxyglucose was found to be an excellent non-metabolized analogue of D-glucose in oxidation experiments. D-glucose oxidation was inhibited by KCN, p-chloromercuribenzoic acid and carbonyl cyanide m-chlorophenylhydrazone; and activated by p-benzoquinone. Iodoacetate had no action. Comparative cellulose thin-layer chromatography including 2-ketogluconate and 2,5-diketogluconate (produced by Janthinobacterium lividum) as standards, showed that gluconate was oxidized to 2-ketogluconate by S. marcescens and E. cypripedii, and 2-ketogluconate was oxidized to 2,5-diketogluconate by E. cypripedii. The diversity of D-glucose oxidation products in the Enterobacteriaceae could have some taxonomic applications.
17 citations
TL;DR: In this paper, the separation of enantiomers using forced-flow planar chromatographic techniques such as overpressured layer chromatography and various rotation planar methods such as ultra-microchamber rotation plansar chromatography is reported for the first time.
15 citations
TL;DR: Aberrant expression of O‐acetylated sialic acids was associated with adenocarcinoma of the colon, leading to a nearly complete loss of di‐ and tri‐O‐acetelated sIALic acids.
Abstract: The presence of mono-, di-, and tri-O-acetylated sialic acids on human cells was demonstrated by using radiochromatographic and chemical techniques. Human melanoma cells and fresh colon tissue were biosynthetically labeled with 6- (3H) glucosamine. Radiolabeled sialic acids were hydrolytically removed from cellular glycoconjugates, purified by ion-exchange chromatography, and separated by paper chromatography on the basis of the number of O-substitutions on each sialic molecule, This analytical technique characterized radiolabeled sialic acids that migrated with the same Rf as synthetic mono-, di-, and tri-O-acetylated 14C-labeled sialic acids. The mono-O-acetylated sialic acids were characterized by their sensitivity to sodium periodate oxidation and a crude mouse liver esterase preparation. The di- and tri-O-acetylated sialic acids were characterized by their resistance to sodium periodate oxidation and sensitivity to the action of crude mouse liver esterase. Chromatographically separated di- and tri-O-acetylated sialic acids from normal human colon tissue were characterized by their respective ion molecular weights by using fast-atom bombardment-mass spectrometry. Using these methods, we chemically characterized mono, di-, and tri-O-acetylated sialic acids expressed on human cells. Aberrant expression of O-acetylated sialic acids was associated with adenocarcinoma of the colon, leading to a nearly complete loss of di- and tri-O-acetylated sialic acids.
10 citations
TL;DR: In this paper, the transxylosylation reaction products of β-Xylosidase-1, excreted by Penicillium wortmanni IFO 7237 using β-(1→4)-xylobiose as substrate, have been separated by chromatography on activated charcoal into four fractions, designated as P-1.
Abstract: The transxylosylation reaction products of β-xylosidase-1, excreted by Penicillium wortmanni IFO 7237 using β-(1→4)-xylobiose as substrate, have been separated by chromatography on activated charcoal into four fractions, designated as P-1, P-2, P-3, and P-4, respectively. They were further purified by preparative paper chromatography. The characterization and structural analysis were done by measurement of the degree of polymerization (DP) and specific rotation followed by methylation analysis. Moreover, the enzymatic structural analysis of transxylosylation products, with high performance liquid chromatography (HPLC), allowed the confirmation of each structure. The first product, P-1, was β-(1→3)-xylobiose and the second, P-2, was β-(1→4)-xylotriose, but, P-3 was O-β-d-xylopyranosyl-(1→3)-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose or isomeric xylo-triose and P-4 was assumed to be O-β-d-xylopyranosyl-(1→4)-[O-β-d-xylopyranosyl-(1→3)]-O-β-d-xylopyranosyl-(1→4)-d-xylopyranose.
9 citations
TL;DR: Elution patterns from the columns and fluorescence and UV absorption peaks suggest that this compound is a pteridine, which is further supported by the fact that both, folic acid and 6-biopterin can replace the action of the isolated factor on PBG-ase.
Abstract: A low molecular weight, heat-stable factor has been purified from Euglena gracilis supernatant fraction by employing gel filtration, cation and anion exchange and paper chromatography. This endogenous compound stimulates porphobilinogenase (PBG-ase) (EC 4.3.1.8) activity, an enzyme of the porphyrin biosynthetic pathway. 10⁻⁷ ᴍ folic acid and 10⁻⁴ ᴍ 6-biopterin produced a significant activation, equivalent to 2-4 units of the purified factor. Elution patterns from the columns and fluorescence and UV absorption peaks suggest that this compound is a pteridine. This conclusion is further supported by the fact that both, folic acid and 6-biopterin can replace the action of the isolated factor on PBG-ase. The mechanism of stimulation is discussed.
4 citations
TL;DR: The results suggest that the trans-methylglutaconate shunt of mevalonate metabolism functions in the aorta, as constituents of diacylglycerols.
3 citations
3 citations
TL;DR: A new electrochromatoscanning method has been developed for the quantitative analysis of micro-volume samples by paper chromatography that permitted the analysis of amino acid samples as small as 1 nmole.
Abstract: A new electrochromatoscanning method has been developed for the quantitative analysis of micro-volume samples by paper chromatography. This method permitted the analysis of amino acid samples as small as 1 nmole. Amino acids such as β-alanine, glycine, L-glutamic acid and L-aspartic acid in seaweeds were analyzed using this method.
TL;DR: A phenomenon related to on-plate decomposition is presented and an inclusion compound was formed with γ-cyclodextrin in the spotting solution, followed by a mobile phase containing hexadecyltrimethylammonium bromide as a micelle generator, which proved to be successful for preventing degradation during chromatography.
Abstract: The increased production of drugs requires a concomitant assessment of drug purity. Chromatography in general, and thin layer chromatography in particular, play an important role in determination of the impurity profiles of drug candidates. However, in using chromatography to determine impurities, the chemist must be careful, since extraneous zones or spots do not always indicate impurities. They may instead be artifacts, produced in the chromatographic system. In this paper we present a phenomenon related to on-plate decomposition. MK0912 was chosen as a model compound. To overcome the on-plate degradation an inclusion compound was formed with γ-cyclodextrin in the spotting solution, followed by a mobile phase containing hexadecyltrimethylammonium bromide as a micelle generator. This technique proved to be successful for preventing degradation during chromatography.
TL;DR: In this article, the authors used the n-butanol-acetic acid-water (4:1:1) system with aniline phthalate as revealing agent.
Abstract: The component composition of the organic acids was determined by the method of [i], the composition carbohydrates by [2], and that of the free amino acids by paper chromatography [3]; neutral lipids were extracted with n-hexane (bp 40-60°C) from the air-dry comminuted material in a Soxhlet apparatus [4]; and the tocopherols in the oil were determined by a standard method [5]. Analysis showed that the amount of organic acids in the leaves was 3.61% and in the influorescences 1.93%. Paper chromatography in the solvent system n-butanol-formic acidwater (18:2:9) (the revealing agent being a solution of Bromophenol Blue) showed that the heartleaf oxeye leaves contained tartaric (Rf 0.25), malic (Rf 0.48), oxalic (Rf 0.70), and two unidentified acids. Tartaric, malic, and one unidentified acid were detected in the influorescences. The sum of the free amino acids in the leaves amounted to 3.60%, in the stems to 2.89%, and in the inflorescences to 2.05%. It was found by descending paper chromatography (the solvent being n-butanol-acetic acid-water (4:1:1) and the revealing agent 2% ninhydrin in acetone) that leaves of heartleaf oxeye contained cysteine (Rf 0.ii), lysine (rf 0.14), arginine + asparagine (Rf 0.21), histidine (Rf 0.32), threonine (Rf 0.38), alanine (Rf 0.40), tyrosine (Rf 0.45), tryptophan (Rf 0.52), valine (Rf 0.55), phenylalanine (Rf 0.57), and leucine (Rf 0.64). The stems contained ii and the inflorescences seven amino acids. The total amount of carbohydrates in the leaves was 3.01%, in the leaves 2.44%, and in the influorescences 1.97%. To study the qualitative composition of the carbohydrates we used the n-butanol-acetic acid-water (4:1:5) system with aniline phthalate as revealing agent. Chromatographic analysis showed that the leaves contained galactose (Rf 0.16), glucose (Rf 0.18), arabinose (Rf i0.21), and one unidentified sugar. The leaves and inflorescencescontained galactose, glucose, arabinose, and one unidentified sugar. The total amount of neutral lipids in the leaves of heartleaf oxeye was 2.45%, in stems 0.49% and in the influorescences 2.30%. In addition, we studied the amount of tocopherols in the oil (mg-%): in the oil obtained from the leaves it was 3.72, from the inflorescences 3.20, and from the stems 0.089. The results obtained characterize this plant as a medicinal and nutritional raw material.
TL;DR: This chapter focuses on the studies with radioactive tracers in vivo of carbon metabolism, and the use of labeled substrates with whole cells and to alternative methods for analysis of the resulting labeled metabolites.
Abstract: Publisher Summary This chapter focuses on the studies with radioactive tracers in vivo of carbon metabolism Photosynthetic carbon metabolism in cyanobacteria may be studied by exposing photosynthesizing cells to 14 CO 2 , subsequently killing the cells, and then separating and identifying the labeled metabolites by a suitable chromatographic technique Certain types of kinetic tracer studies are complex and require specialized equipment While these requirements are described in this chapter, simpler alternatives are presented for those interested in less complex or less quantitative investigations The information obtained from tracer studies in vivo can be used not only to map metabolic pathways but also to study metabolic regulation, as has been the case with light-dark regulation in green algae The present discussion is devoted mostly to the use of labeled substrates with whole cells and to alternative methods for analysis of the resulting labeled metabolites The classic method of analysis by two dimensional paper chromatography is still the method of choice for some workers because of its capability of separating a broad range of metabolites such as sugar phosphates, sugars, amino acids, and carboxylic acids Variations involving thin-layer chromatography and electrophoresis have been used with success and provide useful alternatives to paper chromatography
Journal Article•
TL;DR: In this paper, a ternary solvent mixtures were used for increasing paper chromatography of three monossacharides, including n-butanol, ethyl acetate and cyclohexanol.