Cathodic Reduction of Isatin-3-oxime

1993 ◽  
Vol 58 (8) ◽  
pp. 1803-1812
Author(s):  
Alexander Hudák ◽  
Adam Košturiak ◽  
Alexander Hanudeľ ◽  
Pavol Meľuch
Keyword(s):  
Molecular Species ◽  
Electronic Spectroscopy ◽  
Paper Electrophoresis ◽  
Cathodic Reduction ◽  
The Other ◽  
Hydrolytic Cleavage ◽  
Oxime Group ◽  
Acid Anion ◽  
Negative Wave ◽  
Polarographic Wave

The molecule of isatin-3-oxime was studied polarografically over the region of pH 1 to 13. Cathodic reduction within the region of pH 1 to 10.5 gives rise to a single four-electron polarographic wave due to the reduction of the oxime group, whereas two polarographic waves are observed at pH 10.5 to 13: one is due to the reduction of the isatin-3-oxime anion, the other, more negative wave is associated with the reduction of the oxime group in the α-oxime isatinic acid anion, which is the product of hydrolytic cleavage of the isatin ring in the basic pH region. The experimental results give evidence that the substance can exist as seven ionic and molecular species in dependence on pH. The species have been confirmed polarographically, by IR and electronic spectroscopy, potentiometrically and by paper electrophoresis.

Extraction and Characterization of Gibberellins from Hordeum vulgare L. Seedlings

1974 ◽  
Vol 1 (2) ◽  
pp. 183 ◽  
Author(s):  
KF Faull ◽  
BG Coombe ◽  
LG Paleg
Keyword(s):  
Mass Spectrometry ◽  
Dry Weight ◽  
Paper Electrophoresis ◽  
The Other ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Liquid Chromatography ◽  
Fresh Weight ◽  
Hordeum Vulgare L ◽  
Layer Chromatography

Two gibberellins, one GA1-like, the other GA3-like, were identified in the extracts of roots and tops of 8-,11- and 15-day-old barley seedlings by paper chromatography, paper electrophoresis, thin-layer chromatography, gas-liquid chromatography and bioassay procedures, followed by combined gas chromatography-mass spectrometry. The amounts of gibberellins in the seedlings ranged from 7 to 11 ng per plant. The concentrations of gibberellins in the seedlings were 32-320 ng/g dry weight and 5-28 ng/g fresh weight; concentrations in the roots were higher than those in the shoots.

Intercellular Glycosaminoglycans in Human Cancer

1979 ◽  
Vol 65 (6) ◽  
pp. 677-686 ◽  
Author(s):  
Maria Cristina Cella ◽  
Gabriella Fibbi ◽  
Cristina Cantini ◽  
Zita Del Panta ◽  
Simonetta Vannucchi ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Molecular Species ◽  
Normal Tissue ◽  
Human Cancer ◽  
Electrophoretic Pattern ◽  
Neoplastic Transformation ◽  
Relative Increase ◽  
The Other ◽  
Cellulose Acetate Electrophoresis ◽  
Consistent Feature

Intercellular glycosaminoglycans (GAGs) from various tissues were analyzed by cellulose acetate electrophoresis and enzymatic treatment with specific mucopolysaccharidases. Each tissue exhibits a particular composition of sulfated and unsulfated molecular species. Invariably, malignant human neoplasias and their metastases show striking variations in the electrophoretic pattern typical of the corresponding normal tissue. An absolute or relative increase in surface ChS A/C and HA seems to be a consistent feature of neoplastic transformation. On the other hand, the GAGs composition of benign noninfiltrative tumors does not vary greatly with respect to the original normal tissue.

[5,10,15,20-Tetrakis(2,6-dimethoxyphenyl)porphyrinato]nickel(II)–toluene–dichloromethane (3/2/4):a mixed solvate

2007 ◽  
Vol 63 (11) ◽  
pp. m2824-m2824
Author(s):  
Diane Conrad ◽  
Jennifer DeCoskey ◽  
Christopher Yeisley ◽  
Matthias Zeller ◽  
Allen D. Hunter ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Glacial Acetic Acid ◽  
Electronic Spectroscopy ◽  
The Other ◽  
Inversion Center ◽  
Asymmetric Unit ◽  
Nickel Ion ◽  
H Nmr ◽  
Nmr Data ◽  
Toluene Molecule

The crystal structure, electronic spectroscopy, and 1H NMR data for the title compound, [Ni(C52H44N4O8)]·0.67C7H8·1.33CH2Cl2, are reported. The compound was prepared by the reaction of nickel(II) acetate with the ligand in refluxing glacial acetic acid. The asymmetric unit consists of 1.5 nickel porphyrins, two dichloromethane molecules and one toluene molecule. One of the nickel–porphyrinate molecules is located on an inversion center and is planar in the solid state, while the other assumes a saddle-shaped geometry. In both cases, the nickel ion is four-coordinate.

scholarly journals THE MOLECULAR WEIGHT OF ANTIBODIES

1937 ◽  
Vol 65 (3) ◽  
pp. 393-414 ◽  
Author(s):  
Michael Heidelberger ◽  
Kai O. Pedersen
Keyword(s):  
Molecular Weight ◽  
Molecular Species ◽  
Principal Component ◽  
The Other ◽  
Type I ◽  
Egg Albumin ◽  
Type Iii ◽  
Sedimentation Constant ◽  
Other Hand ◽  
Immune Rabbit

1. Highly purified rabbit Type III pneumococcus anticarbohydrate proved to be homogeneous in the ultracentrifuge and its sedimentation constant, 7.0·10–13, did not differ from that of the principal component of normal rabbit globulin or of immune rabbit globulin containing up to 50 per cent of anti-egg albumin. The molecular weight of antibody in the rabbit is therefore probably very close to that of the principal normal globulin component, namely, 150,000. 2. Highly purified horse Type I pneumococcus anticarbohydrate, on the other hand, was only homogeneous in the ultracentrifuge when prepared from sera stored without preservative. Its sedimentation constant, 18.4·10–13, coincided with that of the principal globulin component in most of the Felton solutions and purified antibody solutions studied. The molecular weight of pneumococcus anticarbohydrate in the horse is probably three to four times that of the principal normal globulin component. 3. The significance of the differences between pneumococcus anticarbohydrate formed in the rabbit and in the horse is discussed. 4. Results are given of ultracentrifuge studies on the molecular species in solutions of egg albumin-anti-egg albumin specific precipitates dissolved in excess egg albumin. The implications of the results are discussed.

Four electrophoretic methods compared for diagnosis of type III hyperlipoproteinemia.

1979 ◽  
Vol 25 (8) ◽  
pp. 1471-1475 ◽  
Author(s):  
K Kuba ◽  
K Lippel ◽  
I D Frantz
Keyword(s):  
Family Study ◽  
Paper Electrophoresis ◽  
Polyacrylamide Gel ◽  
The Other ◽  
Lipid Research ◽  
Central Laboratory ◽  
Type Iii ◽  
First Degree Relatives ◽  
Type Iii Hyperlipoproteinemia ◽  
Precipitation Technique

Abstract Blood drawn from 192 probands and 1129 first-degree relatives who were participants in a collaborative family study of hyperlipoproteinemia at nine Lipid Research Clinics was used to prepare aliquots of whole plasma and top (d less than 1.006 g/mL) and bottom (d greater than 1.006 g/mL) ultracentrifugal fractions. Each aliquot was analyzed at a central laboratory by electrophoresis on paper, agarose, and polyacrylamide gel, and by a combined electrophoretic precipitation technique. The electrophoretograms were evaluated for the presence or absence of a "floating-beta" lipoprotein band. All four methods agreed completely for 92.3% of the samples. An additional 2.0% of the samples were in agreement for three electrophoretic methods, but the paper electrophoretic results were not interpretable. Another 1.9% were considered to be "floating-beta" positive by paper electrophoresis but negative by the other three electrophoretic methods.

scholarly journals Quantum fidelity susceptibility in excited state quantum phase transitions: application to the bending spectra of nonrigid molecules

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Jamil Khalouf-Rivera ◽  
Miguel Carvajal ◽  
Francisco Perez-Bernal
Keyword(s):  
Phase Transitions ◽  
Excited State ◽  
Molecular Species ◽  
Quantum Phase Transitions ◽  
Quantum Phase ◽  
The Other ◽  
Two Dimensional ◽  
Nonrigid Molecules ◽  
Bending Modes ◽  
Quantum Fidelity

We characterize excited state quantum phase transitions in the two dimensional limit of the vibron model with the quantum fidelity susceptibility, comparing the obtained results with the information provided by the participation ratio. As an application, we locate the eigenstate closest to the barrier to linearity and determine the linear or bent character of the different overtones for particular bending modes of six molecular species. We perform a fit and use the optimized eigenvalues and eigenstates in three cases and make use of recently published results for the other three cases.

scholarly journals Isolation and fractionation of glycopeptides from porcine thyroglobulin

1971 ◽  
Vol 123 (3) ◽  
pp. 407-414 ◽  
Author(s):  
Minoru Fukuda ◽  
Fujio Egami
Keyword(s):  
Molecular Weight ◽  
Sialic Acid ◽  
Chemical Composition ◽  
Column Chromatography ◽  
Gel Filtration ◽  
Paper Electrophoresis ◽  
Alkaline Treatment ◽  
The Other

1. Glycopeptides were isolated by gel filtration on Sephadex G-25 and Sephadex G-50 from a Pronase digest of porcine thyroglobulin. 2. Isolated glycopeptides were separated into five main fractions on a column of DEAE-Sephadex A-25. Of these fractions I to III were further purified by SE-Sephadex C-25 or DEAE-Sephadex A-25 column chromatography. Several of the purified glycopeptides were homogeneous on paper electrophoresis. 3. Based on the chemical composition and molecular weight of the fractionated glycopeptides, two distinct types of heterosaccharide chain were demonstrated. 4. One type of the heterosaccharide unit consisted of four to eight residues of mannose and two residues of glucosamine and had a molecular weight of 1000–1700. The other type of unit contained sialic acid, fucose and galactose in addition to mannose and glucosamine and had a molecular weight of about 3600. 5. Mild alkaline treatment of the glycopeptide did not result in the destruction of threonine and serine. 2-Acetamido-1-N-(4-l-aspartyl)-2-deoxy-β-d-glucopyranosylamine was isolated from partial acid hydrolysates.

Protonation de l'adénine, de la purine et de l'adénosine en milieu acide fort

1984 ◽  
Vol 62 (5) ◽  
pp. 995-1000 ◽  
Author(s):  
Robert L. Benoit ◽  
Monique Fréchette
Keyword(s):  
Chemical Shifts ◽  
Imidazole Ring ◽  
Pyrimidine Ring ◽  
The Other ◽  
Medium Effect ◽  
Hydrolytic Cleavage ◽  
The Third ◽  
Nmr Data ◽  
Solid Bases ◽  
Proton Chemical Shifts

In view of a previously proposed enthalpy value for the second protonation of adenine, a calorimetric and nmr spectroscopic study has been made of the protonation of biologically important bases B: adenine, purine, adenosine and, incidentally, that of imidazole and 3-amino pyridine. Heats of solution of the solid bases, and their carbon-13 and proton chemical shifts were determined as a function of HClO4 and H2SO4 concentration. Our results demonstrate that, contrary to previous usage, a strong medium effect precludes the use of the calorimetric results to calculate the thermodynamic functions for the protonation reactions. On the other hand, the carbon-13 nmr data are successfully interpreted on the basis of the Cox and Yates excess acidity method. The values obtained for [Formula: see text] and [Formula: see text] are, respectively: adenine −0.43, −4.23, purine −1.66, < −6, adenosine −1.4 with hydrolytic cleavage of the glycosidic bond. The protonation sites are confirmed as being essentially on the imidazole ring for the second protonation and on the pyrimidine ring (N-3) for the third one.

Relation of the fibrinolytic mechanism to other proteolytic systems in plasma

1969 ◽  
Vol 173 (1032) ◽  
pp. 407-410 ◽  
Keyword(s):  
Human Plasma ◽  
Molecular Species ◽  
Glass Powder ◽  
Plasma Sample ◽  
Fibrinolytic System ◽  
The Other ◽  
Active Centre ◽  
Two Factors ◽  
Close Integration ◽  
Plasma Kinin

I shall first try to illustrate the close integration of the fibrinolytic system with other proteolytic processes in blood, by recalling some of the efforts to segregate it from the intrinsic plasma kinin forming system. Attempts at clear chemical distinction between plasmin and the specific kininogenases were complicated by two factors: (1) the activities associated with plasmin resided possibly in more than one molecular species (Markus & Ambrus 1960); (2) plasma kininogenases were distinguished from plasmin only by minor quantitative or by negative criteria. The kininogenases act only on natural or synthetic substrates which are attacked by plasmin as well. The active centre of plasma kininogenase differs from that of plasmin mainly by the substrates which it does not attack. Its constitution is probably very similar to the centres of plasmin, thrombin, trypsin and chymotrypsin. Clearer differences appeared when the activation of the pre-active enzymes in human plasma was considered (Eisen 1963). Figure 1 shows that streptokinase levels activating all plasminogen in human plasma induced much smaller kinin formation than did glass powder. Yet, when clotted, the first plasma lysed in a few seconds, and the other in more than 24 hours. Similarly, the small kinin formation resulting from the complete activation by streptokinase, was greatly enhanced when activation by glass or kaolin was superimposed in the same plasma sample.

Qualitative and quantitative differences in the isoelectrofocusing profile of biologically active lutropin in the blood of normally menstruating and post-menopausal women

1981 ◽  
Vol 97 (2) ◽  
pp. 166-175 ◽  
Author(s):  
F. Strollo ◽  
J. Harlin ◽  
H. Hernandez-Montes ◽  
D. M. Robertson ◽  
A. A. Zaidi ◽  
...  
Keyword(s):  
Molecular Species ◽  
Temporal Changes ◽  
Biologically Active ◽  
The Other ◽  
Plasma Samples ◽  
Menopausal Women ◽  
Menstruating Women ◽  
Post Menopausal ◽  
Ph Range ◽  
Alkaline Material

Abstract. A single bolus of 100 μg of gonadoliberin (LRH) was administered intravenously to 8 post-menopausal and 9 normally menstruating women and blood was withdrawn before and 30, 60, 120 and 240 min after LRH stimulation. The plasma samples obtained at different time intervals from women showing a sufficiently high response to LRH (menopausal: 8, menstruating: 3) were combined and 2 ml samples of each pool were fractionated in triplicate by electrofocusing on sucrose density gradient. In addition, two plasma pools, obtained 30 min following LRH stimulation, one from 4 normally menstruating women (exhibiting a relatively low LH-response) and the other from 2 normally menstruating women aged 40, were analyzed in the same way in duplicate electrofocusing experiments. The hLH activity was determined in each electrofocusing fraction by an in vitro bioassay method following elution and purification by gel filtration. The LH activity was distributed as four major peaks at pI values of 7.10 ± 0.05, 7.58 ± 0.06, 8.10 ± 0.04 and 8.54 ± 0.05 and a broad area of activity comprising a number of peaks in the pH range of 8.69–9.50. The analysis of the data revealed marked differences in the relative distribution of the various molecular species present in the blood of menopausal women and of normally menstruating women. A molecular species exhibiting a pI value of 7.10 was invariably present (10 – 15% of the total) in all samples of post-menopausal plasma (PMP) but was consistently absent from all samples of midcycle plasma (MCP). The amount of relatively 'less alkaline' material (eluted from pH range 7.37–8.32) was significantly higher (P < 0.001) in the PMP samples compared to MCP samples. On the other hand, in the MCP samples the amount of relatively 'more alkaline' material eluted from the pH range 8.33–9.50 was significantly (P < 0.001) higher (about 60% of the total recovered activity) compared to the PMP samples (about 30% of the total). Following LRH stimulation significant temporal changes were observed in the relative contribution of various molecular species to the hLH profile. A gradual increase, up to 60 min, in the material eluted in the pH range 6.87–7.36 in the post-menopausal plasma samples was accompanied by a gradual decrease in the material eluted in the pH range 7.84–8.32. Two hours after LRH stimulation a significant drop was found in the material collected from pH range 8.33–8.68, with a concomitant rise in the material eluted in the pH range 8.69–9.50. This last mentioned shift was also observed in the plasma of normally menstruating women. It is concluded that major differences exist in the composition of biologically active hLH species present in the peripheral blood of post-menopausal and normally menstruating women. Moreover, significant temporal changes occur in the composition of circulating hLH species following stimulation by LRH both in post-menopausal and in normally menstruating women.

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