scholarly journals THE PERIODATE-SCHIFF REACTION: SPECIFICITY, KINETICS, AND REACTION PRODUCTS WITH PURE SUBSTRATES

1965 ◽  
Vol 13 (6) ◽  
pp. 423-430 ◽  
Author(s):  
ARNE DAHLQVIST ◽  
INGE OLSSON ◽  
ÅKE NORDÉN
Keyword(s):  
Nucleic Acids ◽  
Simple Relation ◽  
Test Tube ◽  
Reaction Products ◽  
Chromatographic Mobility ◽  
Reaction Specificity ◽  
Rate Of Reaction ◽  
Pure Substances ◽  
Schiff Reaction ◽  
Aldehyde Groups

A quantitative test-tube method has been used to study the periodate-Schiff reaction of a number of pure substances. The rate of reaction, the amount of color produced, and in some cases the amount of periodate consumed, have been measured. The dye produced by different carbohydrates has been analyzed by spectrophotometry and paper chromatography. Glycogen, starch and dextran reacted slowly and produced much less color than the corresponding amount of free monosaccharides. Oligosaccharides and heteropolysaccharides were either periodate-Schiff-negative or very weakly positive. Proteins and nucleic acids were negative. There was no simple relation between the intensity of the periodate-Schiff reaction and the amount of periodate consumed or the amount of aldehyde groups formed on the oxidation by periodate. The dyes formed with different carbohydrates had essentially the same absorption curve, but differed in their chromatographic mobility.

scholarly journals The influence of chromatin compactness on the stoichiometry of the Feulgen-Schiff procedure studied in model films. II. Investigations on films containing condensed or swollen chicken erythrocyte nuclei.

1975 ◽  
Vol 23 (12) ◽  
pp. 891-900 ◽  
Author(s):  
W A Duijndam ◽  
P van Duijn
Keyword(s):  
Staining Intensity ◽  
Nuclear Material ◽  
Reaction Products ◽  
Chromatin Compactness ◽  
High Reduction ◽  
Protein Components ◽  
Schiff Reaction ◽  
Chicken Erythrocytes ◽  
Aldehyde Groups ◽  
Very High

As models for different states of chromatin compactness, nuclei from chicken erythrocytes were isolated and either osmotically swollen or kept as condensed as possible. Both types of nuclei were then fixed and incorporated into polyacrylamide films. Hydrolysis with 5 N HCl and staining with Schiff's reagent of these model films were studied using several parameters. The phosphate content of the films was analyzed as a parameter for the depolymerization losses and the staining with Schiff's reagent as a parameter for the apurinic acid (APA) content. The loss of ultraviolet absorbance from the films and the accumulation of ultraviolet absorbing substances in the hydrolyzing acid were monitored as parameters for the progress of hydrolysis. Conversion of the generated aldehyde groups to APA-Schiff chromophore is shown to take place with the same stoichiometry for both types of nuclei as well as for DNA in model films. It is further shown that the nuclei- and DNA-films are suitable models for investigating the influence of chromatin compactness on the course of the Feulgen-Schiff reaction. For the most compact form of chromatin studied, a very high reduction in staining intensity of up to 40% could be demonstrated after certain normally applied hydrolysis times. This is due primarily to a decrease with a factor of 2.3 of the depurination rate constants of these models (from 0.030/min to 0.013/min). Therefore prolonged hydrolysis periods are required to obtain the same APA concentrations, but then depolymerization processes cause losses of nuclear material. The differences in depurination rates could be explained by a decrease in [H3O]+ in the neighborhood of the purine-sugar linkages, caused by the presence of fixed positive charges form the protein components of the chromatin. These findings may explain the cytophotometrically determined differences in chromophore yield of 10-20% found in the nuclei of cells with different states of compactness of their chromatin. The descending part of the Feulgen hydrolysis curve represents the depolymerization of APA and loss by diffusion of the reaction products. In the Appendix, cytophotometric data of cells have been analyzed to show that this part of the hydrolysis curve may be used to estimate the acid stability of chromatin complexes. The depurination and depolymerization rates found closely correspond with the data obtained from the model films.

Oxidation of hydrocarbons in the liquid phase: n-dodecane in a borosilicate glass chamber at 200 °C

1969 ◽  
Vol 47 (22) ◽  
pp. 4175-4182 ◽  
Author(s):  
B. D. Boss ◽  
R. N. Hazlett
Keyword(s):  
Liquid Phase ◽  
Borosilicate Glass ◽  
Current Knowledge ◽  
Reaction Chamber ◽  
Cyclic Ethers ◽  
Reaction Products ◽  
Isomer Distribution ◽  
Oxidation Of Hydrocarbons ◽  
Volatile Products ◽  
Rate Of Reaction

The 5-h oxidation of n-dodecane at 200 °C by air at 1 atm is reported for experiments in a borosilicate glass reaction chamber equipped with a gas bubbler. The rate of reaction was limited by the rate of oxygen diffusion from the gas phase due to the rapid reaction of dissolved oxygen. The reaction products were analyzed in aliquots taken periodically from the reaction chamber. Chemical analyses, gas–liquid phase chromatography (g.l.p.c.), tandem g.l.p.c.-mass spectroscopy, infrared, and ultraviolet were used to identify products accounting for 98% of the oxygen reacted. The isomer distribution of the dodecenes, dodecanols, and dodecanones formed, as well as the distribution of carboxylic acids, were determined. Three classes of intramolecular reaction products, cyclic ethers, cyclic hydrocarbons, and lactones, were detected. Many volatile products were detected. A filterable precipitate obtained after 10 h of oxidation was studied using infrared attenuated total reflectance techniques. A reaction mechanism is discussed based on current knowledge of other systems, the products identified, and the stoichiometry of the reaction.

5-Nitroimidazoles. II: Unexpected reactivity of ronidazole and dimetridazole with thiols

1993 ◽  
Vol 71 (9) ◽  
pp. 1349-1352 ◽  
Author(s):  
Michel Girard ◽  
François Clairmont ◽  
Aspi Maneckjee ◽  
Nicole Mousseau ◽  
Brian A. Dawson ◽  
...  
Keyword(s):  
Biological Systems ◽  
Product Distribution ◽  
Veterinary Drugs ◽  
Spectroscopic Techniques ◽  
Reaction Products ◽  
Nucleophilic Reaction ◽  
Alternative Path ◽  
Rate Of Reaction ◽  
Bound Residues ◽  
Aqueous Conditions

Ronidazole and dimetridazole, two important veterinary drugs, were found to react readily in the presence of cysteine, under neutral aqueous conditions, leading to the formation of 5-S-cysteinyl-1-methylimidazole-2-methanol carbamate and 5-S-cysteinyl-1,2-dimethylimidazole respectively through nitro displacement. The reaction products were identified by spectroscopic techniques. The rate of reaction was accelerated by increasing the pH of the medium and was accompanied by a slight change in the product distribution. The reaction was also observed, albeit at a slower rate than that of cysteine, with glutathione, another ubiquitous thiol substrate found in biological systems. While this type of nucleophilic reaction has previously been observed for suitably substituted nitrobenzene derivatives, to the best of our knowledge its occurrence with nitro-heteroaromatics has never been reported. The ready reaction of the parent nitro drugs under such mild aqueous conditions suggests that this may be an alternative path for the formation of nonextractable bound residues in tissues.

Mechanism of interference with the Jaffé reaction for creatinine.

1987 ◽  
Vol 33 (7) ◽  
pp. 1129-1132 ◽  
Author(s):  
M H Kroll ◽  
N A Roach ◽  
B Poe ◽  
R J Elin
Keyword(s):  
Carbonyl Group ◽  
Equilibrium Constants ◽  
Molar Absorptivity ◽  
Reaction Products ◽  
Cyclic Ketones ◽  
Common Structure ◽  
Aliphatic Ketones ◽  
Rate Of Reaction ◽  
The Common

Abstract We investigated the mechanism of the Jaffé reaction for determination of creatinine by studying the spectrophotometric, kinetic, and equilibrium properties of the reaction of picrate with creatinine and with cyclic and aliphatic ketones. Absorbance spectra for the reaction products of picrate with all the ketones were superimposable with that of creatinine (Amax, 490 nm). Cyclic ketones not containing nitrogen had a molar absorptivity less than half that of creatinine and equilibrium constants approximately 0.01 that of creatinine. Aliphatic ketones, except for benzylacetone, had molar absorptivities similar to that of creatinine, but all of these compounds had equilibrium constants approximately a tenth or less that of creatinine. The common structure for all of the compounds reacting with picrate is the carbonyl group. The variable magnitude of interference for aliphatic and cyclic ketones is ascribable to the different rate constants, molar absorptivities, and equilibrium constants as compared with creatinine. Structures adjacent to the carbonyl group significantly affect the absorptivity and equilibrium constant, but steric hindrance is the major factor affecting the rate of reaction. We postulate that the carbonyl group is required for the Jaffé reaction, and we suggest a mechanism for the reaction.

scholarly journals THE KINETICS OF THE PERIODATE-SCHIFF REACTION OF HUMAN LEUKOCYTE HOMOGENATES

1967 ◽  
Vol 15 (11) ◽  
pp. 646-651 ◽  
Author(s):  
INGE OLSSON ◽  
ARNE DAHLQVIST
Keyword(s):  
Periodate Oxidation ◽  
Human Leukocyte ◽  
Test Tube ◽  
High Concentration ◽  
Human Leukocytes ◽  
Considerable Fraction ◽  
Quantitative Test ◽  
Pas Reaction ◽  
Schiff Reaction ◽  
Kinetics Of

The periodate-Schiff (PAS) reaction of homogenized human leukocytes has been studied with a quantitative test tube method. The leukocytes contain glycogen, which gives a slow formation of chromogen during the periodate oxidation, and one or several more rapidly reacting, nonglycogen substances. The latter substances are quantitatively more important for the PAS reaction than glycogen. Nonglycogenic, rapidly reacting PAS-positive substances are present in a high concentration in the specific leukocyte granules. A considerable fraction of the rapidly reacting PAS-positive material in leukocyte homogenates can be extracted with lipid solvents.

scholarly journals SYNTHESIS AND RESEARCH OF NITROGEN-CONTAINING XANTHANE GUM DERIVATIVES

2020 ◽  
Vol 9 (5(74)) ◽  
pp. 57-62
Author(s):  
O.R. Ahmedov ◽  
N.Sh. Rahmatova ◽  
H.S. Talipova ◽  
Z.S. Alihonova ◽  
A.S. Turaev
Keyword(s):  
Xanthan Gum ◽  
Condensation Reaction ◽  
Oxidation States ◽  
Reaction Products ◽  
Scanning Calorimetry ◽  
Quantitative Content ◽  
Degree Of Oxidation ◽  
Physicochemical Methods ◽  
Aldehyde Groups ◽  
Derivatives Of

This study presents the results concerning the synthesis of nitrogen-containing derivatives of xanthan gum. The authors obtained xanthan gum derivatives with various oxidation states through the preliminary reaction of periodic oxidation of the polysaccharide. Through the physicochemical methods of analysis, the structure and established quantitative content of aldehyde groups in the macromolecular chain of the polysaccharide were proved. It was possible to carry out a condensation reaction with guanidine and to synthesize new macromolecular derivatives in the presence of reactive aldehyde groups in the structure of xanthan gum. The synthesized derivatives were further investigated through IR spectroscopy, thermogravimetry, differential scanning calorimetry, and elemental analysis for nitrogen content. Furthermore, it is found that the amount of guanidine and the degree of substitution in the synthesized compounds are 15.3-39.0% and 34-85 mol.%. Finally, when using modified xanthan gum with a different degree of oxidation it is possible to vary the quantitative content of guanidine and the degree ofsubstitution in the reaction products.

The Histochemical Demonstration of Keratin by Methods involving Selective Oxidation

1951 ◽  
Vol s3-92 (20) ◽  
pp. 393-402
Author(s):  
A. G. EVERSON PEARSE
Keyword(s):  
Periodic Acid ◽  
Cobalt Nitrate ◽  
Histochemical Demonstration ◽  
Performic Acid ◽  
Cysteic Acid ◽  
Acid Oxidation ◽  
Reaction Products ◽  
Periodic Acid Schiff ◽  
Periodic Acid Oxidation ◽  
Schiff Reaction

1. Oxidation of tissues with performic acid gives rise to histochemically detectable reaction products particularly in two classes of material. These are keratin and lipoids of the phosphatide class. 2. Three methods have been evolved for visualizing the effect of performic acid on cystine-containing structures; two of these (performic acid/Schiff and perfoiTnic acid/cobalt nitrate) also record the effect on lipoids. 3. An attempt has been made to elucidate the chemistry of the reactions and it is suggested that oxidation of cystine in the tissues gives rise not only to cysteic acid (alanine-beta-sulphonic) but to another acid (alanine-beta-sulphinic). The latter is responsible for the positive reaction with Schiff's solution. 4. The Schiff reaction with performic acid oxidized lipoids is due to the formation of substances giving the reactions of aldehydes. It is possible that similar groups may be produced from lipoid molecules by periodic acid oxidation and that these and not polysaccharides (1.2 glycols) are responsible for the periodic acid-Schiff reaction in such cases.

scholarly journals Unique chemical activity in porous YbB2C2 ceramics with high porosity and high compressive strength

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Zhihui Li ◽  
Jixin Chen ◽  
Hao Zhang ◽  
Jinxing Yang ◽  
Minmin Hu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Raw Materials ◽  
Chemical Activity ◽  
High Porosity ◽  
Reaction Products ◽  
X Ray Diffraction ◽  
X Ray ◽  
High Compressive Strength ◽  
Rate Of Reaction ◽  
Unique Chemical

AbstractHigh purity layered YbB2C2 powder is synthesized by a boro/carbothermic reduction method using YbBO3, B4C and graphite powders as raw materials. Its X-ray diffraction data are presented, and the space group P4/mbm (No. 127) is confirmed. The lattice parameters are a = b = 5.3389 Å and c = 3.5683 Å, and the atom positions are Yb (0.0000, 0.0000, 0.0000), B (0.3621, 0.8621, 0.5000), and C (0.1606, 0.6606, 0.5000). Porous YbB2C2 ceramics have a high porosity in the range of 69.89–58.11% and a high compressive strength in the range of 19.49–63.44 MPa. Furthermore, the as-produced porous YbB2C2 ceramics show unique chemical activity. Porous YbB2C2 ceramic with a porosity of 69.89% emits so much heat that it can burn a piece of paper when this ceramic is wetted by water. The rate of reaction between the porous YbB2C2 ceramic and water can be simply controlled by adjusting the porosity. The solid reaction products are YbB6, C and an unknown amorphous phase.

A Comparative Study on Reactions of Hydrogen Peroxide and Peracetic Acid with Lignin Chromophores. Part 1. The Reaction of Coniferaldehyde Model Compounds

Holzforschung ◽  
2000 ◽  
Vol 54 (2) ◽  
pp. 144-152 ◽  
Author(s):  
George X. Pan ◽  
Liam Spencer ◽  
Gordon J. Leary
Keyword(s):  
Hydrogen Peroxide ◽  
Peracetic Acid ◽  
Oxidation Products ◽  
Reaction Pathways ◽  
Main Reaction ◽  
Side Chain ◽  
Reaction Products ◽  
Efficient Utilization ◽  
Model Compounds ◽  
Rate Of Reaction

Summary The reactions of chromophoric model compounds of the coniferaldehyde type with hydrogen peroxide and peracetic acid have been investigated in relation to lignin-retaining bleaching. Analysis of the main reaction products indicated that the side chain of coniferaldehyde could cleave either between the α, β double bond or between the β, γ bond. Comparison of possible reaction pathways to the formation of oxidation products from hydrogen peroxide and peracetic acid suggested that peracetic acid is more effective than hydrogen peroxide. Advantages of peracetic acid over hydrogen peroxide include a faster rate of reaction, more efficient utilization of the bleaching agent and less likelihood of producing new chromophores.

On structural formulas of basic fuchsin and aldehyde-schiff reaction products

1975 ◽  
Vol 45 (4) ◽  
pp. 255-265 ◽  
Author(s):  
Holde Puchtler ◽  
Susan N. Meloan ◽  
Barbara R. Brewton
Keyword(s):  
Reaction Products ◽  
Basic Fuchsin ◽  
Structural Formulas ◽  
Schiff Reaction
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