Synthesis of Some Anilides of 2-Alkyl-4-pyridinecarboxylic Acids and Their Photosynthesis-Inhibiting Activity

1997 ◽  
Vol 62 (4) ◽  
pp. 672-678 ◽  
Author(s):  
Miroslav Miletín ◽  
Jiří Hartl ◽  
Miloš Macháček
Keyword(s):  
Silver Nitrate ◽  
Alkaline Hydrolysis ◽  
Oxidative Decarboxylation ◽  
Inhibiting Activity ◽  
Pyridinecarboxylic Acid ◽  
Acyl Chlorides ◽  
Oxygen Evolution Rate ◽  
Alkanoic Acids ◽  
Homolytic Alkylation ◽  
Pyridinecarboxylic Acids

Homolytic alkylation of 4-pyridinecarbonitrile with radicals generated by silver nitrate catalyzed oxidative decarboxylation of alkanoic acids and subsequent alkaline hydrolysis afforded 2-alkyl-4-pyridinecarboxylic acids 2a-2e. These were converted into the halogeno-hydroxy substituted anilides 3a-3r via acyl chlorides by reaction with the respective aminophenols at 10 °C. Of the compounds tested, 5-chloro-2-hydroxyphenylamide of 2-butyl-4-pyridinecarboxylic acid 3h showed the highest effect upon oxygen evolution rate in spinach chloroplasts system. The structure-photosynthesis-inhibiting activity relationships are briefly discussed.

scholarly journals Some Anilides of 2-Alkylthio- and 2-Chloro-6-Alkylthio-4-Pyridinecarboxylic Acids: Synthesis and Photosynthesis-Inhibiting Activity

Molecules ◽  
2001 ◽  
Vol 6 (7) ◽  
pp. 603-613 ◽  
Author(s):  
Miroslav Miletín ◽  
Martin Doležal ◽  
Veronika Opletalová ◽  
Jiří Hartl ◽  
Katarína Král’ová ◽  
...  
Keyword(s):  
Inhibiting Activity ◽  
Pyridinecarboxylic Acids

scholarly journals Equilibrium constants of the sorption of pyridinecarboxylic acids by polystyrene type sulfocationite

2020 ◽  
Vol 64 (10) ◽  
pp. 55-62
Author(s):  
Elena V. Ostapova ◽  
◽  
Sergey Yu. Lyrschikov ◽  
Heinrich N. Altshuler ◽  
◽  
...  
Keyword(s):  
Nicotinic Acid ◽  
Cation Exchanger ◽  
Isonicotinic Acid ◽  
Equilibrium Constants ◽  
Sorption Activity ◽  
Pyridinecarboxylic Acid ◽  
Cation Exchangers ◽  
Sulfonic Cation Exchanger ◽  
Acid Cation ◽  
Pyridinecarboxylic Acids

The processes of sorption of pyridine-3-carboxylic (nicotinic) and pyridine-4-carboxylic (isonicotinic) acids by sulfonic acid cation exchangers of the polystyrene type (CU-2-4 and CU-2-8) from aqueous solutions with different pH values were studied. Analysis of the FTIR spectra of isonicotinic acid, isonicotinic acid sulfate, and CU-2-8 sulfonic cation exchanger filled with isonicotinic acid showed that pyridinecarboxylic acid is in the protonated form in the polymer phase. Experimental data of the equilibrium distribution of acids in the aqueous solution-cation exchange system have been obtained. The values of the equilibrium constants for ion exchange and ligand sorption processes involving various forms of pyridinecarboxylic acid, sulfonic cation exchanger, and protons were calculated. The equilibrium constants for the ion exchange of sulfocationite protons by pyridinecarboxylic acid cations from solution are in the range 3.3-4.4. The selectivity of sulfonic cation exchangers to cations increases in the sequences proton < nicotinic acid cation < isonicotinic acid cation. The values of the equilibrium constant for ligand sorption of molecules are 195-220 dm3/mol for isonicotinic acid and reach 320-330 dm3/mol for nicotinic acid, i.e. the sorption activity of the H-form of the cation exchanger is higher in relation to nicotinic acid molecules. A change in the amount of a crosslinking agent (from 4% to 8% divinylbenzene) in a polystyrene type sulfonic cation exchanger does not significantly affect its sorption activity towards pyridinecarboxylic acids.

A rapid silver-impregnation technique on ultra-thin sections for Electron Microscopy

1993 ◽  
Vol 51 ◽  
pp. 242-243
Author(s):  
K. Chien ◽  
R.C. Heusser ◽  
M.L. Jones ◽  
R.L. Van de Velde
Keyword(s):  
Electron Microscopy ◽  
Silver Nitrate ◽  
Silver Impregnation ◽  
Sodium Borate ◽  
Renal Diseases ◽  
Distilled Water ◽  
Thin Sections ◽  
Impregnation Technique ◽  
Centrifuge Tube ◽  
Simplified Procedure

Silver impregnation techniques have been used for the demonstration of the complex carbohydrates in electron microscopy. However, the silver stains were believed to be technically sensitive and time consumming to perform. Currently, due to the need to more specifically evaluate immune complex for localization in certain renal diseases, a simplified procedure in conjunction with the use of the microwave has been developed and applied to renal and other biopsies. The procedure is as follows:Preparation of silver methenamine solution:1. 15ml graduated, clear polystyrene centrifuge tube (Falcon, No. 2099) was rinsed once with distilled water.2. 3% hexamethylene tetramine (methenamine) was added into the centrifuge tube to the 6ml mark.3. 3% silver nitrate was added slowly to the methenamine to the 7ml mark while agitating. (Solution will instantly turn milky in color and then clear rapidly by mixing. No precipitate should be formed).4. 2% sodium borate was added to the solution to the 8ml mark, mixed and centrifuged before use.

HERG channel inhibiting activity of Rauvolfia nukuhivensis alkaloid content

Planta Medica ◽  
2014 ◽  
Vol 80 (16) ◽  
Author(s):  
NJ Martin ◽  
EA López ◽  
G Lecellier ◽  
M Nicolas ◽  
C Paetz ◽  
...  
Keyword(s):  
Alkaloid Content ◽  
Herg Channel ◽  
Inhibiting Activity

Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

2019 ◽  
Vol 14 (1) ◽  
pp. 110
Author(s):  
Assiss. Prof. Dr. Sabiha Mahdi Mahdi ◽  
Dr. Firas Abd K. Abd K.
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Silver Nitrate ◽  
Surface Hardness ◽  
Mechanical Tests ◽  
Hardness Tester ◽  
Acrylic Resins ◽  
The Difference

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.

Sign in / Sign up

Export Citation Format

Share Document