Paper Chromatographic Techniques Research Articles

No evidence for bradykinin hydrolysis in human erythrocyte suspensions: 1H NMR studies.

In view of their permeability to small peptides, it has been postulated that human erythrocytes may play a role in terminating the action of some circulating peptide hormones. Work using classical paper chromatographic techniques for detecting free amino acids indicated that the octapeptide, des-(Arg9)-bradykinin, enters these cells and its amino-terminal arginine residue is released by cytosolic aminopeptidase-P. We have used 1H NMR to monitor directly the release of arginine from bradykinin. The hydrolytic reaction rate in hemolysates, with an initial peptide concentration of 13.0 mmol l-1 was 6.5 mmol (1 packed red cell)-1 h-1. But no reaction was evident after a 4.5-h incubation with intact cells, thus contradicting the earlier suggestion that erythrocytes are involved in the primary inactivation of this hormone. This is consistent with our previous findings that the pentapeptide leu-enkephalin fails to enter human erythrocytes but that its lower-order degradation products may do so.

Determination of lactulose and soya oligosaccharides in infant formula milk feeds.

A paper chromatography technique is described for the separation and quantification of minor sugars in infant formula milks. The precision and reliability of the technique are described. Infant milk feeds of various types were analysed and found to contain up to 11.4 mmol/l of the non-absorbed sugar lactulose. Soya derived feeds may contain a significant residue of non-absorbable oligosaccharides.

Antimicrobial Activities of Some Flavonoid Compounds

6 flavonoid compounds, namely kaempferol, quercetin, myricetin, rutin, naringin, and formononetin were separated from different plant materials. They were identified using column and paper chromatography techniques, and physicochemical methods were applied to determine their structure. Isolated flavonoids were tested for their antimicrobial property against different bacterial and fungal strains as test organisms.

Thin Layer and Paper Chromatographic Separations of d-Block Cations Complexed with ANILS

Abstract Diverse binary, ternary and quaternary mixtures of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Hg(II) and Au(III) d-block cations complexed with p-dimethylamino- and p-diethylamino- anils of thiopheneglyoxal have been separated by thin layer and paper chromatographic techniques. But quantitative separations have been done by thin layer chromatography, on account of wide difference in migration rates and high compectedness of complexes on gel layers. Chromatogram fragments visualised as such have been estimated spectrophotometrically.

Hochleistungsflüssigchromatographische trennung der herzwirksamen glykoside von Convallaria majalis L. durch serienschaltung verschieden polarer “reversed-phase” säulen International Research Congress on Natural Products as Medicinal Agents, Strasbourg, 6.–11. Juli 1980; Teil der Diplomarbeiten R. Kern und E. Bamberg-Kubelka, Universität Wien, 1979 und 1980.

A systematic investigation of high-performance liquid chromatographic (HPLC) conditions employing 27 cardenolide glycosides of Convallaria majalis showed that LiChrosorb RP-2 possesses the best separation efficiency for the “polar” glycosides whereas LiChrosorb RP-8 can be used for analysis of the “less polar” fraction. For crude extracts from Convallaria majalis the best results were obtained by coupling of a LiChrosorb RP-2 precolumn and two analytical columns (LiChrosorb RP-2 and LiChrosorb RP-8) in series in combination with stepwise gradient elution with acetonitrile-water. A comparison of the new method with the paper chromatographic technique currently used showed that the HPLC method gives much more information about the composition of these complex mixtures of cardiac glycosides. It also offers great advantages for the quantitative determination of single cardenolides in Convallaria majalis L.

Synthesis of some organic poly(aminium phosphate)s: 4

Poly(aminium phosphate)s were prepared by precipitation from aqueous solution. The composition of these derivatives was established by analysing for nitrogen and phosphorus. Weight average molecular weights were determined by intrinsic viscosity determination. The intrinsic viscosity has been determined by replacing the usual extrapolation of specific viscosity to zero concentration ( η sp C vs. CO) with the extrapolation of linear transformation. G = AF + B where G = y α − x , F = x α − x and α = x M + x m (where y = η sp C and x m and x M denote concentration). The values for Huggins constants ( k′ + k″) were also calculated and found to be characteristic of linear chain polymers. The R g values for poly(aminium phosphate)s have been determined in New Ebel's solvent, by a paper chromatographic technique. A linear relationship between degree of polymerization and R g values is indicative of the linear chain polymeric character of these derivatives. The polyelectrolyte behaviour of these polymers has also been established by conductivity measurements.

Characterization of some organic poly(aminiumphosphate)s

Metachromatic reactions of MB and AO are studied with poly(aminium phosphate)s. The main band(α) at 665 mμ and 492 mμ for MB and AO are shifted to 580 mμ and 455 mμ respectively (β-bands). The metachromatic values at different concentrations of poly(aminium phosphate)s are also reported. The dye association for MB with these polymer derivatives is investigated conductometrically as well. It is observed that MB can be at the most bind with the phosphate residue of polymer upto 1∶1 molar ratio. The polymeric nature was further established by paper chromatographic technique in Terry's, Ebel's & Pfrengle's solvents.

Separation of inorganic iodide in the analysis of some iodoorganic radiopharmaceuticals

AbstractA paper chromatography technique using 33% w/v aqueous solution of ammonium sulphate as a solvent has been applied for fast separation of inorganic radioactive iodide from labelled organic compound in the analysis of some iodoorganic radiopharmaceuticals of common use.L‐triiodothyronine, L‐thyroxine, Rose Bengal and bromosulphthalein are retained at the starting spot while iodide migrates at Rf 0.5. The separation is obtained at a development path of 5cm in about 10min.Sodium o‐iodohippurate, however, migrated at Rf 0.4 and its separation from inorganic iodide was not achieved under the conditions employed.

The stability of99mTc phosphorus compounds in plasma both in vivo and in vitro

The in vivo and in vitro stability of99mTc hydroxyethlylidene diphosphonate, 99mTc methylenediphosphonate and99mTc pyrophosphate in plasma has been studied using paper chromatographic technique as the analytical tool. The results indicate that the amounts of99mTc activity found both at the origin and Rf range of99mTcO4 − for in vivo experiments are slightly greater than those for either in vitro or control experiments. However, this amount of99mTc activity represents about 0.16–0.4% of the injected dose. Therefore, it is suggested that99mTc phosphorus radiopharmaceuticals are stable in vivo and neither oxidation nor hydrolysis of these bone imaging agents occurs in the blood.

Analysis of radiolysis products of aqueous uracil + N2O solutions

Various products from the irradiation of solutions of uracil + N2O with 60Co gamma rays were separated by paper chromatographic technique using 14C labelled materials. Identity of the isolated products was investigated by spectrophotometric and kinetic decomposition studies. Thus at least eight radiolytic products of uracil such as cis- and trans-uracil glycols, 5-hydroxy-6-hydro and 6-hydroxy-5-hydro compounds, isobarbituric acid and three dimeric products were identified. Yields of these products were determined at different pH values; a good material mass balance was achieved; the mechanism involved is discussed.

Thin Layer Chromatographic Systems for the Classification and Identification of Antibiotics

Abstract Several comparative chromatoqraohic systems described in the literature may he useful for facilities dealing with a relatively large number of different antibiotics, such as clinical laboratories engaged in the identification of antbiotics in human serum; research laboratories screening for new antbiotics; and regulatory agencies testing drug preparations. Ishida et al. (1) introduced the “summarized paper chromatogram” which is obtained when Rf values computed from several solvent systems are represented graphically. Retina (2) classified 62 antibiotics on the basis of graphical representation using paper chromatographic techniques. Later Betina and Nemec (3) used paper chromatography (PC) with buffered solutions for the classification of antibiotics. Snell et al. (4) used paper chromatographic classification of antibiotics in crude preparations.

Formation of dimers in the gamma radiolysis of aqueous solutions of pyrimidines and N2O.

Aqueous solutions of pyrimidines (such as uracil and thymine) containing N2O (125 mM) were irradiated with Co-60 gamma rays source and analysed with paper chromatography technique using suitable solvent developing systems. Among the various radiation-induced products, the three different products located with lower Rf values are U. V. absorbing in character. Spectroscopic analysis such as N.M.R., U.V. and mass spectrometry showed tentatively that these products are dimeric compounds; silylation technique assisted for such investigation. These dimers are the major products in the radiolysis of the pyrimidines and N2O system ; uracil produced dimers which constituted 71% of the total uracil loss and thymine 33%.

Isolation and sequential studies of peptides from tryptic digest of trichloroacetic acid precipitate of partly autolyzed alkaline protease from Aspergillus flavus

A partly autolyzed preparation of the alkaline protease from As. flavus, denatured by trichloroacetic acid, was resolved into the high and low molecular weight part; the amino acid composition of both parts was similar to that of the native protease. The high molecular weight part was subjected to tryptic digestion; the digest was fractionated by chromatography on a sulfonated ion exchange resin and by paper electrophoresis and paper chromatography techniques. The peptides isolated were characterized by amino acid analysis and terminal end group analysis. Peptides obtained in larger quantities were sequenced. The data on peptides obtained in this study are compared with the results of earlier work on nonradioactive peptides from a partial hydrolysate of the [32P]DIP-labeled enzyme.

GRAFT COPOLYMERIZATION OF VINYL MONOMERS ONTO CELLULOSE WITH CERIC ION: DETAILED EXAMINATIONS OF THE C1-C2 GLYCOL IN THE REDUCING CELLULOSE-ENDGROUP AS THE GRAFTING SITE

Styrene has been graftcopolymerized with aqueous solutions of Ce (NO3)6•2NH4(CAN) onto cellulose samples modified chemically in different manner, i.e., oxidized, reduced and oximated. The polymerization was conducted in the absence of mineral acid. It was found that the copolymerization did proceed not for the oxidized and oximated cellulose but only for the reduced cellulose, in which intact C1-C2 glycols are retained in the reducing endgroup. From these results it was confirmed that the C1-C2 glycol acts as the grafting site. Truely grafted polystyrene side-chains were isolated from graft product by using a technique of thin-layer chromatography combined with acid hydrolysis of cellulose backbone and the chemical constitution of their chain ends have been investigated with a paper-chromatographic technique. It was found that the side chain contained aldehyde residue at their chain ends. This result implied that the grafting grew up from a free radical produced on the C1 position of reducing cellulose-endgroup.

Separation of radioactive histamine and some of its metabolites by one-dimensional paper chromatography

A simple one—dimensional paper chromatography technique is described for the separation of radioactive histamine and some of its metabolites in blood and tissues. After removal of protein, the supernatant fluid (200 μl) is subjected to two—stage one—dimensional paper chromatography. This enables large numbers of samples to be chromatographed simultaneously. Using this technique in conjunction with liquid scintillation counting, it was possible to monitor the small amounts (0.02 nCi) of radioactive histamine and its metabolites in serial blood samples.

Quantitation of Copper in Some of the Copper Base Alloys by Paper Chromatographic Technique

Quantitation of Copper in Some of the Copper Base Alloys by Paper Chromatographic Technique

The Detection of Nectar Sugars in Field-Collected Culex nigripalpus and Its Application1

A conventional paper chromatographic technique is described to quantitate the nectar feeding by 32P-marked Culex nigripalpus Theobald for 11 consecutive days after being released in the field. Of the resting and blood-seeking adults that were captured, overall 57.5-100% were positive for glucose, as compared to 3-69.1% positive for fructose. The presence of these free sugars in the captured adults indicated that they had taken a nectar meal. The nectar-feeding by adult mosquitoes during the 11 consecutive days showed fluctuations in the relative quantities of glucose and fructose. It is suggested that an investigation of nectar-feeding by mosquitoes in nature cannot rely solely on a fructose test, but a chromatographic test for several nectar sugars is more amenable to such an investigation.

Mode of Action of Gentamicin Antibiotics Produced by Micromonospora purpurea

Gentamicin antibiotics were produced fermentatively by Micromonospora purpurea. They were separated into gentamicin C1, C1a and C2 by paper chromatographic technique, using chloroform, methanol, and 17.0% of NH4OH (2: 1: 1 v/v) as developing solvent. The different antibiotics showed variable antimicrobial activities. The gentamicin antibiotics inhibited the biosynthesis of DNA and RNA of the proteins, present in the cells of Staphylococcus aureus.

Quantitative determination of the glutathione, cysteine, and N-acetyl cysteine conjugates of acetaminophen by high-pressure liquid chromatography

A quantitative method for the estimation of the glutathione, cysteine, and N-acetyl cysteine conjugates of acetaminophen obtained from microsomal incubations has been developed using high-pressure liquid chromatography (HPLC). As little as 5 ng of the thiol conjugates of [ring- 14C]acetaminophen can be measured with good precision from microsomal incubations with minimal sample preparation. High-pressure liquid chromatography offers distinct advantages over the standard separation techniques of thin-layer, paper, or gel filtration chromatography for the separation and quantitation of the polar thiol metabolites of acetaminophen.

Gentamicins

Gentamicin is a new broad-spectrum antibiotic, basic and water-soluble, produced and developed by Schering Corporation-Bloomfield, New Jersey (1967 and 1968). It is produced by Micromonospora purpurea, a member of a genus of microorganisms from which no other antibiotics have been derived. Paper chromatographic techniques showed the components of gentamicin complex designated as C', C'a, and C2. Gentamicins are bactericidal antibiotics, active in vivo in low concentrations against a wide spectrum of both Gram-positive and Gram-negative organisms. Among the responsive Gram-positive groups of microorganisms are Staphylococcus aureus including many resistant penicillinase producing strains and group A betahemolytic Streptococci. Among the clinically more important species of Gram-positive organisms responsive to gentamicin are both indole-positive and indole-negative Proteus, Pseudomonas, Escherichia coli, Aerobacter, Klebsiella, Salmonella, and Shigella. The production of gentamicins was improved by adding cobalt to the growth medium.