Urea derivatives

Ebook "Specific intermolecular interactions of nitrogenated and bioorganic compounds" development of the thermodynamic theory of specific intermolecular interactions to a wider spectrum of nitrogenated and bioorganic compounds: amino alcohols, amino acids, peptides and urea derivatives. The fundamentals of an unconventional approach to the theory of H-bonding and specific interactions are formulated based on a concept of penta- coordinated carbon atoms.

603p tudohanhtau1006 29-03-2024 3 1   Download

The Urea-Hydrogen Peroxide complex was synthesized from urea, hydrogen peroxide by using microwave assisted method and characterized by FT-IR. This Urea-Hydrogen Peroxide complex could be employed as an oxidizing agent for metal-free oxidation reaction of benzylic alcohols to carboxylic acids corresponding.

8p viengels 25-08-2023 4 2   Download

We hereby report a new method for preparation of 3,4-dihydroquinolin-2(2H) -one starting from the methyl 2-(2-carboxyethyl)benzoic acid. The acid functionality, adjacent to the methylene, was regiospecifically converted to the desired methyl ester and the remaining acid functionality was transferred into acyl azide. Curtius rearrangement of acyl azide followed by trapping with aniline and alcohols provided the corresponding urea and urethane derivatives.

8p langthannam 29-12-2021 6 0   Download

15N labeled soluble metallo- and metal-free phthalocyanines are described for the first time. The complexes were synthesized starting from phthalic anhydride derivatives using 98% 15N enriched urea. The effects of the substitution pattern, aggregation, and coordinated metal on 15 N chemical shifts in liquid state NMR were studied.

11p langthannam 29-12-2021 13 1   Download

Twenty-five new hydroxy- and methoxy-substituted 4,6-diarylpyrimidin-2(1H)-ol (20–34) and 4,6-diarylpyrimidine-2(1H)-thiol derivatives (35–44) were synthesized from the reaction of the corresponding 1,3-diaryl-2-propene-1- one compounds (1–19) with urea or thiourea using the solid-phase microwave method. All the new synthetic compounds (20–44) were evaluated with regard to their α-glucosidase activity. However, only compounds 22–25, 27, 31, 34, 35, 37, and 40 exhibited a greater inhibitory effect than standard acarbose. The IC50 values of the active compounds ranged between 2.36 and 13.

16p tudichquannguyet 29-11-2021 9 1   Download

Pyrimidine derivatives are well known due to their remarkable pharmacological potential in various fields of science, and they are also present in some natural substances like DNA and RNA. These scaffolds manifest diversified biological activities such as antimicrobial, antiinflammatory, anti-HIV, antitubercular, antitumor, antineoplastic, and antimalarial. A pyrimidine ring is constructed when chalcones, amidines, guanidine, nitriles, isocyanates, urea, thiourea, and aminopyrazoles undergo condensation, coupling, or cyclization reactions.

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The rapid population growth, fast agricultural extensions, increased urbanization and industrialization have together stressed the exploration of eco-friendly sustainable and renewable energy resources in meeting the energy needs. Biodiesel is a fuel that comprises mono-alkyl esters of long-chain of fatty acids derived from vegetable oils. Microalgae have tremendous capacity of biosynthesis of TAG compared to other terrestrial crops. The aim of present work was to study effect of various nitrogen sources on the patterns of microalgae growth and the lipid content.

10p angicungduoc8 07-11-2020 18 2   Download

Chalcones have a place with the flavonoid family and show a few very important pharmacological activities. They can used as initial compounds for synthesis of several heterocyclic compounds. The compounds with the backbone of chalcones have been reported to possess various biological activities.

14p vijiraiya2711 27-05-2020 9 1   Download

Pyrazolines show different biological activities. In recent years, interest in the chemistry of hydrazonoyl halides has been renewed. 1,3,4-Thiadiazoles are one of the most common heterocyclic pharmacophores with a wide range of biological activities.

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Inducing calcium carbonate precipitation is another important function of urease in nature. The process takes advantage of the supply of carbonate ions derived from urea hydrolysis and of an increase in pH generated by the reaction, effects that in the presence of Ca2+ ions lead to the precipitation of CaCO3.

9p trinhthamhodang1 14-11-2019 15 0   Download

Urease (urea amidohydrolase, EC 3.5.1.5) is a nickel-containing enzyme produced by plants, fungi, and bacteria that catalyzes the hydrolysis of urea into ammonia and carbamate. Urease is of historical importance in Biochemistry as it was the first enzyme ever to be crystallized (1926). Finding nickel in urease’s active site (1975) was the first indication of a biological role for this metal. In this review, historical and structural features, kinetics aspects, activation of the metallocenter and inhibitors of the urea hydrolyzing activity of ureases are discussed.

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World population is expected to reach 9.7 billion by 2050, which makes a great challenge the achievement of food security. The use of urease inhibitors in agricultural practices has long been explored as one of the strategies to guarantee food supply in enough amounts. This is due to the fact that urea, one of the most used nitrogen (N) fertilizers worldwide, rapidly undergoes urease-driven hydrolysis on soil surface yielding up to 70% N losses to environment.

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In this study, CuO-doped material fabricated from rice husk ash and red mud was modified by CeO2 promoter and urea using the impregnation method. The obtained samples were investigated for catalytic degradation of aromatic derivatives (benzene, toluene, and p-xylene - BTX) at a temperature range of 275 to 450o C. This demonstrated that all samples were highly active in the BTX treatment.

6p caygaocaolon1 13-11-2019 14 2   Download

Most of the VOCs probably derived from indoor sources. However, the wall cavity was an apparent source of acetaldehyde, toluene and xylenes and the belly space was a source of 2-butanone, lower volatility aldehydes and aromatic hydrocarbons. Indoor minus outdoor VOC concentrations varied with time. Adjusted formaldehyde concentrations exhibited the most temporal variability with concentrations ranging from 25 µg m-3 to 128 µg m-3 and the lowest concentrations occurring in winter months when indoor RH was low.

148p ut_hai_can 29-12-2012 52 4   Download

In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom: C=O. It is common to several classes of organic compounds, as part of many larger functional groups. The term carbonyl can also refer to carbon monoxide as a ligand in an inorganic or organometallic complex. Other organic carbonyls are urea and the carbamates, the derivatives of acyl chlorides chloroformates and phosgene, carbonate esters, thioesters, lactones, lactams, hydroxamates, and isocyanates.

68p loc5heo 07-06-2011 121 14   Download