scholarly journals Study of uric acid oxidation reaction products in medium of ammonia or primary amines

2021 ◽  
Vol 104 (4) ◽  
pp. 30-38
Author(s):  
А.А. Minakova ◽  
◽  
M.V. Chikina ◽  
S.G. Il’yasov ◽  
◽  
...  
Keyword(s):  
Uric Acid ◽  
Oxidation Reaction ◽  
High Energy ◽  
Potassium Ferrocyanide ◽  
Primary Amines ◽  
Acid Oxidation ◽  
Reaction Products ◽  
Polycyclic Compounds ◽  
Starting Compound ◽  
Derivatives Of

This work is considered in more detail the most important stage of obtaining one of the promising heteroatomic polycyclic compounds 3,7,10-trioxo-2,4,6,8,9,11-hexaaza[3.3.3]propellane (THAP). THAP is a potential compound for creating high-energy substances due to the presence of six nitrogen atoms in the structure and tight packing. Uric acid is the starting compound in the THAP synthesis chain. When it is oxidized by sodium persulfate or potassium ferrocyanide, 1,5-diaminoglycoluril is formed, from which the propellane structure is formed by the tricyclization reaction. This work expanded the range of oxidants for the conversion of uric acid to 1,5-diaminoglycoluril. It was found that 1,5-diaminoglycoluril was formed with a yield of 29 % when using equimolar proportions of uric acid and KMnO4. When using MnO2 in a ten times more excess, the yield of 1,5-diaminoglycoluril was 38 %. The article also presents the results of a study of the interaction of uric acid with some amines. The reaction of interaction of uric acid with benzylamine was studied in more detail, the reaction products of which were 4-benzylimino-5-benzylaminoallantoin, 4- benzylimino-1-benzylamino-allantoin and 4-benzyliminoallantoin. Based on the synthesis of 4- benzyliminoallantoin, a number of promising derivatives of 4-iminoallantoin were obtained, namely 4- ethyliminoallantoin, 4-propyliminoallantoin, 4-i-propyliminoallantoin, 4-n-butyliminoallantoin, 4-i- butyliminoallantoin, 4-tert-butyliminoallantoin.

Reactions of 2-Acyl-1,3-indandiones with Nitrogen Nucleophiles

1994 ◽  
Vol 59 (12) ◽  
pp. 2734-2740 ◽  
Author(s):  
Pavel Hrnčiar ◽  
Eva Švanygová
Keyword(s):  
Silica Gel ◽  
Primary Amines ◽  
Reaction Products ◽  
Carbonyl Carbon ◽  
Nitrogen Base ◽  
Nitrogen Nucleophiles ◽  
Derivatives Of ◽  
Twofold Excess

Reactions of 2-acyl-1,3-indandiones with nitrogen nucleophiles were studied rarely. The question, if they react with carbonyl carbon of acyl group or indandione skeleton, has not been answered unambiguously. To make clear the question which carbonyl carbon of 2-acyl-1,3-indandiones enters the reaction with nitrogen nucleophiles we carried out the reactions with 2-acetyl- (Ia), 2-propionyl- (Ib), 2-pivaloyl- (Ic), and 2-benzoyl-1,3-indandione (Id). We used different 2-acyl-1,3-indandiones with the aim to find out if the character of acyl group affects the course of reaction. We used ethoxyamine, primary amines, phenylhydrazine, hydrazine and methylhydrazine as nucleophile reactants. The reactions were carried out in methanol at reflux at 10% excess of nitrogen base. The reactions with phenylhydrazine, hydrazine and methylhydrazine were performed with twofold excess of nitrogen base. The separation of reaction products was carried out by chromatography on silica gel. We found that 2-acyl-1,3-indandiones I react with ethoxyamine both at the acylcarbonyl carbon to produce 2-(1-ethoxyiminoalkyl)-1,3-indandiones II and the carbonyl carbon of indandione skeleton to give rise 3-(ethoxyimino)-2-acyl-1-indanones III. In all cases, the carbonyl carbon of acyl group was preferred (the observed ratio of products II to III was 6 - 8 : 1). From the reaction of 2-acyl-1,3-indandiones with primary amines only the products IV of reaction with the acylcarbonyl carbon were isolated. The hydrazines used reacted with 2-acyl-1,3-indandiones also at carbonyl carbon of acyl group in the first step to produce hydrazones. However, the products isolated in most cases were formed by the attack of hydrazone nitrogen at carbonyl carbon of indandione skeleton giving rise to derivatives of indeno[2,3-d]pyrazole-4-one V. It is interesting that 2-acetyl-1,3-indandione and 2-propionyl-1,3-indandione, reacting with phenylhydrazine and hydrazine, yielded only corresponding hydrazones VI.

NANOELECTROCATALYSTS BASED PALLADIUM FOR FUEL CELLS WITH DIRECT OXIDATION OF FORMIC ACID

2019 ◽  
Vol 6 (3) ◽  
pp. 104-107
Author(s):  
Marina Vladimirovna Lebedeva ◽  
Alexey Petrovich Antropov ◽  
Alexander Victorovich Ragutkin ◽  
Nicolay Andreevich Yashtulov
Keyword(s):  
Formic Acid ◽  
Palladium Nanoparticles ◽  
Oxidation Reaction ◽  
Electrode Materials ◽  
Formic Acid Oxidation ◽  
Energy Sources ◽  
Acid Oxidation ◽  
Direct Oxidation ◽  
Atomic Force ◽  
Formic Acid Oxidation Reaction

In paper electrode materials with palladium nanoparticles on polymer matrix substrates for energy sources have been formed. Nanocomposites were investigated by atomic force and scanning electron microscopy. The catalytic activity of formed electrodes in the formic acid oxidation reaction was evaluated by voltammetry method.

Preparation of carbon-supported Pd-decorated PtCu nanoparticles towards formic acid oxidation reaction

Ionics ◽  
2017 ◽  
Vol 23 (7) ◽  
pp. 1861-1869 ◽  
Author(s):  
Yange Suo ◽  
Chenbin Rong ◽  
Yuxin Guo ◽  
Zhiguo Zhang ◽  
Guilin Hu ◽  
...  
Keyword(s):  
Formic Acid ◽  
Oxidation Reaction ◽  
Formic Acid Oxidation ◽  
Acid Oxidation ◽  
Formic Acid Oxidation Reaction ◽  
Supported Pd

scholarly journals Determination of uric acid in human serum by an enzymatic method using N-methyl-N-(4-aminophenyl)-3-methoxyaniline reagent

2003 ◽  
Vol 68 (8-9) ◽  
pp. 691-698 ◽  
Author(s):  
Milena Jelikic-Stankov ◽  
Predrag Djurdjevic ◽  
Dejan Stankov
Keyword(s):  
Uric Acid ◽  
Human Serum ◽  
Limit Of Detection ◽  
Ascorbate Oxidase ◽  
Acid Oxidation ◽  
Uric Acid Concentration ◽  
Enzymatic Method ◽  
Limit Of Quantification ◽  
Relative Standard

In this work a new enzymatic method for the determination of uric acid in human serum has been developed. The method is based on the oxidative coupling reaction between the N-methyl-N-(4-aminophenyl)-3-methoxyaniline (NCP) reagent and the hydrogen ? donor reagent N-ethyl-N-(2-hydroxy-3-sulfopropyl)-3-methylaniline (TOOS), in the system involving three enzymes: uricase, peroxidase and ascorbate oxidase. Using this method uric acid could be determined in concentrations up to 1.428 mmol/L, with a relative standard deviation of up to 1.8 %. The effect of the medium pH and the NCP concentration on the linearity of the chromogen absorbance versus the uric acid concentration curve was investigated. The influence of the uricase activity on the maximum rate of uric acid oxidation was also examined. The use of the NCP reagent demonstrated a more precise and more sensitive determination of the uric acid compared to the determination with 4-aminoantipyrine (4-AA) as the coupling regent. The sensitivity of the method determined from the calibration curve was 0.71 absorbance units per mmol/L of uric acid; the limit of detection was LOD = 0.0035 mmol/L and the limit of quantification was LOQ = 0.015 mmol/L of uric acid.

scholarly journals Electrochemical Performance Improvement of the Catalyst of the Methanol Micro-Fuel Cell Using Carbon Nanotubes

2019 ◽  
Author(s):  
Mohammad Kazemi Nasrabadi ◽  
Amir Ebrahimi-Moghadam ◽  
Mohammad Hosein Ahmadi ◽  
Ravinder Kumar ◽  
Narjes Nabipour
Keyword(s):  
Carbon Nanotubes ◽  
Fuel Cells ◽  
Fuel Cell ◽  
Carbon Black ◽  
Oxidation Reaction ◽  
High Energy ◽  
Proton Exchange ◽  
Operating Conditions ◽  
High Energy Density ◽  
Methanol Oxidation Reaction

Due to low working temperature, high energy density and low pollution, proton exchange fuel cells have been investigated under different operating conditions in different applications. Using platinum catalysts in methanol fuel cells leads to increasing the cost of this kind of fuel cell which is considered as a barrier to the commercialism of this technology. For this reason, a lot of efforts have been made to reduce the loading of the catalyst required on different supports. In this study, carbon black (CB) and carbon nanotubes (CNT) have been used as catalyst supports of the fuel cell as well as using the double-metal combination of platinum-ruthenium (PtRu) as anode electrode catalyst and platinum (Pt) as cathode electrode catalyst. The performance of these two types of electro-catalyst in the oxidation reaction of methanol has been compared based on electrochemical tests. Results showed that the carbon nanotubes increase the performance of the micro-fuel cell by 37% at maximum power density, compared to the carbon black. Based on thee-electrode tests of chronoamperometry and voltammetry, it was found that the oxidation onset potential of methanol for CNT has been around 20% less than CB, leading to the kinetic improvement of the oxidation reaction. The current density of methanol oxidation reaction increased up to 62% in CNT sample compared to CB supported one, therefore the active electrochemical surface area of the catalyst has been increased up to 90% by using CNT compared to CB which shows the significant rise of the electrocatalytic activity in CNT supported catalyst. Moreover, the resistance of the CNT supported sample to poisonous intermediate species has been found 3% more than CB supported one. According to the chronoamperometry test results, it was concluded that the performance and sustainability of the CNT electro-catalyst show remarkable improvement compared to CB electro-catalyst in the long term.

Reversal of mitochondrial swelling associated with fatty acid oxidation. II. Effects of cytochrome c and carnitine on contraction of fatty acid swollen mitochondria

1968 ◽  
Vol 46 (9) ◽  
pp. 1151-1160 ◽  
Author(s):  
Misako Nakatani ◽  
W. C. McMurray
Keyword(s):  
Fatty Acid ◽  
Cytochrome C ◽  
Energy Requirement ◽  
Liver Mitochondria ◽  
High Energy ◽  
Fatty Acyl ◽  
Water Soluble ◽  
Rat Liver Mitochondria ◽  
Acid Oxidation ◽  
Swelling Agent

Rat liver mitochondria undergo reversible swelling in the presence of a fatty acyl CoA generating system. Contraction of the swollen mitochondria was observed on the addition of either carnitine or cytochrome c. At low concentrations the two agents acted synergistically. At high concentrations cytochrome c completely replaced the requirement for carnitine.Cytochrome c also promoted the contraction of mitochondria swollen in the presence of fatty acid alone, provided that either ATP or ADP was added to initiate the contraction. The stimulation by cytochrome c was greater in the presence of ADP, and the contraction was more sensitive to respiratory inhibitors or dinitrophenol but was less sensitive to oligomycin than in the presence of ATP. Studies of the metabolism of 14C-labelled palmitate during cytochrome c induced contraction showed that decreases in mitochondrial-bound fatty acid and corresponding increases in water-soluble metabolites coincided with the reversal of swelling. The results indicated that the energy requirement for mitochondrial contraction in the presence of cytochrome c was provided by generation of high-energy intermediates coupled to oxidation of the fatty acid swelling agent.

A quaternary metal–metalloid–nonmetal electrocatalyst: B, P-co-doping into PdRu nanospine assemblies boosts the electrocatalytic capability toward formic acid oxidation

2020 ◽  
Vol 8 (5) ◽  
pp. 2424-2429 ◽  
Author(s):  
You Xu ◽  
Shanshan Yu ◽  
Tianlun Ren ◽  
Chunjie Li ◽  
Shuli Yin ◽  
...  
Keyword(s):  
Formic Acid ◽  
Oxidation Reaction ◽  
Formic Acid Oxidation ◽  
Acid Oxidation ◽  
Co Doping ◽  
Electrocatalytic Performance ◽  
Formic Acid Oxidation Reaction

Quaternary PdRuBP nanospine assemblies (PdRuBP NAs) were readily synthesized and they exhibited enhanced electrocatalytic performance toward the formic acid oxidation reaction.

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