Ethyl Urea Research Articles

Effects of storage time and temperature on the concentration of ethyl carbamate and its precursors in wine

A 3-year study was carried out on the effects of time and temperature on the concentration of ethyl carbamate in wine. The study monitored the changing concentration of ethyl carbamate and of urea and citrulline, which are two major precursors of ethyl carbamate in wine. In addition to the formation of ethyl carbamate, both urea and citrulline decayed in other reactions. Kinetic analysis was carried out to model the formation of ethyl carbamate and its dependence on the concentrations of ethanol, urea and citrulline. This led to the development of an equation that can be used to predict the concentration of ethyl carbamate in wine at the point of consumption, resulting from any given storage time and temperature profile. The results were in good agreement with data obtained from similar studies.

Synthesis of Some New Pyrazolopyridines, Pyrazolothienopyridines, Pyrazolopyridothienopyrimidines and Pyrazolopyridothienotriazines

Pyrazolo[3,4-b]pyridine derivative 3a was prepared and reacted with methyl iodide to give 4 or 5 depending on reaction conditions. Oxidation of 3a with iodine produced the corresponding disulphide derivative 6 , whereas oxidation with KMnO 4 gave the corresponding oxo derivative 7 . Oxidation of 4 afforded the corresponding sulphone derivative 8 , which on boiling in NaOH solution gave 7 . The reaction of compound 3a with chloroacetonitrile, ethyl chloroacetate, phenacyl bromide, and chloroacetanilide afforded 9a , b , 11 , and 12 respectively. Cyclication of the products 9a , b , 11 , and 12 yielded 10a , b , 13 , and 14 respectively. The reaction of compound 14 with ethyl orthoformate, nitrous acid, acetic anhydride, benzaldehyde, urea, CS 2 , and phenyl isothiocyanate afforded compounds 15-21 respectively.

Free-Radical Polymerization of (R)-(−)-1-(1-Naphthyl)ethyl(2-methacryloyloxyethyl)urea and Chiral Recognition Ability

(R)-(−)-1-(1-Naphthyl)ethyl(2-methacryloyloxyethyl)urea (NEMOU) was synthesized from 2-methacryloyloxyethyl isocyanate (MOI) and (R)-(+)-1-(1-naphthyl)ethylamine. Radical homopolymerizations of NEM...

Phosphorylation of Ethyl Urethane, Urea, and Acetamide with Bis(chloromethyl)phosphinic Chloride in the Presence of Potassium Carbonate

Bis(chloromethyl)phosphinic chloride reacts with urethane to give phosphorylated urethane, whereas with urea and acetamide the final reaction product is bis(chloromethyl)phosphinic anhydride.

Activation of the N–H bond of ethyl carbamate and urea by ruthenium hydride complexes. Unexpected loss of alcohol or ammonia to yield isocyanato complexes

The complex [RuH2(CO)(PPh3)3]1 reacted with ethyl carbamate (urethane), H2NCO2Et, or urea to yield the complex [RuH(NCO)(CO)(PPh3)3]2, which was spectroscopically characterised. The analogous reaction of [RuH2(PPh3)4]3 gave a mixture of products in which [RuH(NCO)(C6H5Me)(PPh3)3]4 predominates. Treatment of this mixture with CO allowed the isolation of [RuH(NCO)(CO)2(PPh3)2]5 the crystal structure of which was solved by X-ray diffraction. The reactions appear to proceed through the intermediate formation of a N-bonded carbamato or ureido complex, formed by elimination of H2, followed by irreversible elimination of alcohol or ammonia. This synthesis of isocyanate complexes appears to be quite general. The reactivity of the complexes obtained with olefins has been investigated. Only isomerisation was observed, with no evidence for organic isocyanate formation.

Alkylated ureas: mineralization and evaluation as N sources

An incubation experiment was conducted for 11 weeks to study the mineralization of ten alkylated ureas and urea in soil. Six of the alkylated ureas viz. methylurea(MU), 1,3-dimethylurea(1,3DMU), 1,1-dimethylurea(1,1DMU), ethylurea(EU), 1,3-diethylurea(1,3DEU) and butylurea(BU) and urea mineralized during the experiment. Urea mineralized immediately, while alkylated ureas mineralized after an incubation period ranging from less than a week to four weeks (delay period of mineralization). The delay period increased in the following sequence MU < 1,3DMU < EU < BU < 1,1DMU < 1,3DEU, but after the delay period was over the compounds mineralized almost as rapidly as urea. The delay period varied according to the number of carbon atoms in the alkyl group and their position with respect to each other on the molecule. It appeared to be specific for each compound and was apparently not influenced by the presence of urea or other alkylated ureas. This character can be used to develop mixture of various alkylated ureas to obtain N mineralization at the desired time. Rapid evolution of CO2 and N2O was observed during the mineralization of urea as well as alkylated ureas. Increase in soil pH was also observed during this period. The simultaneous ocurrence of these events suggested the formation of urea as an intermediate during the mieralization of alkylated ureas. None of the alkylated ureas showed adverse affect on emergence of wheat seedlings and except DEU and BU at high concentration no other alkylated urea showed any adverse effect on initial growth of wheat seedlings.

Effects of ureas on the kinetics of acid hydrolysis of 1-phenylethyl nitrite in water and in aqueous micellar solutions of sodium dodecyl sulfate

The acid ionization constants of urea, methylurea (MEU), ethylurea (ETU), N,N-dimethylurea (DMU) and tetramethylurea (TMU) have been determined in water and in aqueous micellar solutions of sodium dodecyl sulfate (SDS) from the kinetic study of the acid hydrolysis of 1-phenylethyl nitrite (PEN). The acid hydrolysis in water was inhibited by the addition of urea, as a result of its protonation which decreases the effective H+ concentration. Analysis of the solvent isotope effects and the activation parameters shows that urea does not modify the solvation of the substrates. MEU and ETU show a similar behaviour to that found with urea, but TMU behaves slightly differently, because TMU decreases the relative permittivity of the water mixtures.

Incompatibility conditioned by the Mla gene in powdery mildew of barley: change in permeability to non-electrolytes

Passive permeability of host cells to the non-electrolytes, methyl and ethyl urea, was measured plasmometrically in epidermal tissue from barley ( Hordeum vulgare) inoculated with Erysiphe graminis f.sp. hordei. Incompatibility, conditioned by the Mla gene for resistance, was expressed by hypersensitive collapse of haustorium-containing host cells, 1–2 h after cytoplasmic streaming stopped. Measurements were made about 20 h after inoculation, either before or after the halt in streaming. Before streaming stopped, permeability of haustorium-containing cells to methyl and ethyl urea was reduced about 30%. Permeability to methyl urea was reduced also in neighboring cells without haustoria. Cells in tissues with decreased permeability exhibited high frequencies of concave plasmolysis, indicative of increased adhesion between the plasmalemma and the cell wall. After cytoplasmic streaming stopped, but prior to cell collapse, permeability to ethyl urea was reduced to 50% of values for non-inoculated tissues. The results indicate that structural changes which reduce permeability to non-electrolytes occur in the lipid bilayer of the host plasmalemma and that these changes that may be related to reduced membrane fluidity. These changes are similar in incompatible and compatible host-parasite combinations but occur earlier and to a greater degree with incompatibility.

Permeability to nonelectrolytes as an indicator of change in membrane lipid structure in Hordeum vulgare cells infected by Erysiphe graminis f. sp. hordei

The passive permeability to water and nonelectrolytes of epidermal cells from partially dissected coleoptiles of Hordeum vulagare was investigated in uninfected tissue and in tissue infected with a compatible race of the powdery mildew fungus, Erysiphe graminis f. sp. hordei . Permeability constants were determined plasmometrically for water and for the increasingly nonpolar electrolytes: urea, methyl urea, and ethyl urea. Measurements were taken 48 h after inoculation, usually in heavily infected tissues which exhibited concave plasmolysis. Permeability of cells to water or urea was unchanged by infection. Permeability to methyl urea was reduced significantly in the cultivar Montcalm, but not consistently in Atlas or AlgS. Permeability to ethyl urea in AlgS was reduced by half by infection. The reduced permeability occurred not only in haustoriumcontaining cells. but throughout heavily infected tissue. If tissues were left overnight on plasmolyzing solution of α-methyl glucose, uninfected tissues deplasmolyzed and regained turgor whereas infected tissue did not, suggesting that the α-methyl glucose entered healthy, but not infected cells. The results indicate that infection altered the plasmalemma of host cells, reducing passive permeability to α-methyl glucose and the more lipophilic of the nonelectrolytes tested.

Apparent Molal Volumes of Urea Derivatives in Water–Methanol Mixtures

Abstract Apparent molal volumes (φv) at 25 °C have been obtained for the following urea derivatives in water–methanol mixtures from measurements of the density using an Anton Paar digital densimeter: urea (U), methylurea (MU), ethylurea (EU), 1,1-dimethylurea (1,1-DMU), 1,3-dimethylurea (1,3-DMU), 1,1-diethylurea (1,1-DEU), and 1,3-diethylurea (1,3-DEU). The limiting values φv° were calculated by linear extrapolation using the least-squares method. A plot of φv° vs. X2, the mole fraction of methanol, showed a minimum for each alkylurea studied at low methanol concentrations (X2\simeq0.1), but none for unsubstituted urea: the more alkyl-substituted the urea was, the sharper the minimum. Inspection of the data shows that the assumption of independent solvation on both sides of the urea molecules also holds to a good approximation to the apparent molal volumes both in the pure solvents and in the mixtures.

Al3+ and Ca2+ Alteration of Membrane Permeability of Quercus rubra Root Cortex Cells

This study was undertaken to quantify the effect of aluminum and calcium on membrane permeability. The influence of Ca(2+) (0.2-3.7 millimolar) and Al(3+) (0-3.7 millimolar) on the permeability of root cortical cells of Quercus rubra was measured using three nonelectrolytes (urea, methyl urea, and ethyl urea) as permeators of progressively increasing lipid solubility. Water permeability was also measured. Al(3+) (a) increased membrane permeability to the nonelectrolytes, (b) decreased the membrane's partiality for lipid permeators, and (c) decreased membrane permeability to water. Ca(2+) had effects on permeability that were opposite to those of Al(3+). When Al(3+) and Ca(2+) were tested in combination, these opposite effects counteracted each other. The results suggest that Al(3+) altered the architecture of membrane lipids.

Neoplasia induced in male rats fed lead acetate, ethyl urea, and sodium nitrite.

Sprague-Dawley rats were exposed to 0, 26, or 2600 ppm lead as lead acetate in drinking water for 76 weeks. At 28 weeks of lead exposure, a portion of each group was exposed simultaneously to 6.36 g/kg ethyl urea (EU) and 2.0 g/kg sodium nitrite (NaNO2) for a duration of 20 weeks, and then continued an additional 28 weeks on standard diet free of EU and NaNO2. The animals were observed for incidence, latency, and distribution of tumors. Rats exposed to 2600 ppm lead alone had 81% renal tumors, while rats given 2600 ppm lead in combination with EU/NaNO2 had a 50% incidence. Renal tumors did not occur in the EU/NaNO2 only or EU/NaNO2-26 ppm lead groups. The major tumor type found in EU/NaNO2-exposed rats was lymphosarcoma. Lead did not appear to be syncarcinogenic to the activity of ethylnitrosourea, the carcinogen formed by oral exposure to EU and NaNO2. The lead-induced renal neoplasms were histologically similar to those which occur spontaneously in man and, therefore, may serve as an animal model to study human disease.

Alteration of natural killer cell-mediated cytotoxicity in rats treated with selenium, diethylnitrosamine and ethylnitrosourea

Weanling, female Sprague-Dawley rats were divided into 14 separate groups. Three of these groups were administered 0.5, 2.0 or 5.0 ppm selenium (Se) in the drinking water for 10 weeks. Three groups received intraperitoneal injections of 1, 5 or 10 mg/kg diethylnitrosamine (DEN) twice weekly for 10 weeks. The remaining animals received 0.150% or 0.316% ethylurea (EU) in the feed and 1 or 10 ppm nitrite as sodium nitrite in the drinking water either alone or in combination. Separate groups of rats treated with cyclophosphamide (CY) were included as positive immunosuppressed controls. Following the 10-week chemical exposure period, splenic natural killer (NK) cell-mediated cytotoxicity was assessed by a 4-h chromium release assay using YAC-1 tumor cells as targets. The NK cell cytotoxic response was enhanced in both the low and medium dose selenium-exposed groups. In contrast, rats exposed to 0.316% EU + 10 ppm NO 2 had significantly depressed NK cell activity. CY treatment also resulted in a significant reduction of splenic NK cell cytotoxicity.

Studies on the Utility of Artificial Mutations in Plant Breeding : XIII. Mutagenicity of Several Alkylating Agents in Rice

Five alkylating agents, ethylenimine (EI), ethyl methanesuifonate (EMS), N-nitroso-N -ethyl urea (NEUA), N-nitroso-N-methyl urea (NMUA) and N-nitroso-N-methyl urethane (NMUT), were compared on the mutagenic effectiveness and efficiency in a few agronomic characters of rice. The modes of dose-response of seedling height, survival rate of seedlings and seed fertility in M1 generation were remarkably different with the different agents used : Methylating agents brought about more toxic effects on M1 plants than ethylating agents. The data obtained in M2 indicated that ethylating agents induced the mutations in chlorophyll, heading date and culm length more easily than methylating agents : In comparison of the highest frequency of chlorophyll mutants and variants in the two agronomic characters, NEUA ranked first, followed by EMS, EI, NMUA and NMUT in turn. The orders of the effectiveness and efficiency of mutagens were NEUA>NMUA >EI>NMUT>EMS and NEUA>EI>EMS>NMUA>NMUT, respectively. These results suggest that NEUA is one of the best mutagens in practical plant breeding. The frequency of variants in each of two agronomic characters was quite exactly proportional to that of chlorophyll mutations throughout all the agents applied.

Alterations in the reproductive performance of Habrobracon females following combined treatments with ethylurea and sodium nitrate or nitrite

Ethylurea (EU) and NaNO 2 fed simultaneously to female braconid wasps caused several types of changes in reproductive performance. Early effects included a decrease in (a) the number of vitellogenic oocytes developing into eggs, and in (b) the hatchability of the eggs laid. After a period of no damage to transitional cells there was a late effect expressed as a pronounced reduction in the number of eggs produced from the oogonia, although the hatchability was good. Dissection of the ovarioles revealed gaps in the oogenetic sequence. Most of the specimens showed resorption of the small oocytes and some specimens contained distal masses of undifferentiated cells resembling a tumerous condition. Neither EU nor NaNO 2 alone caused the damage obtained from feeding them in combination, and EU injected along with NaNO 2 was ineffective.

The swelling properties of poly(2-hydroxyethyl methacrylate) hydrogels polymerized by gamma-irradiation and chemical initiation

The swelling behaviour of polyHEMA hydrogels in aqueous solutions of various compounds has been investigated. Gels polymerized using a chemical initiator attained a higher equilibrium hydration in aqueous solutions than those polymerized by ionizing radiation. The difference in equilibrium hydration has been explained in terms of the effect of residual initiator on swelling. Aqueous solutions of sodium chloride, sucrose and glucose were found to dehydrate the gels, while solutions of phenol, urea, acetic acid, acetamide, ethanol, sodium acetate and ethyl urea caused swelling. The extent of swelling was a function of the osmotic activity, size, lipophilicity and number of hydrogen bonding groups of the solute molecule. A linear relationship was found between the swelling rate and the concentration of cross-linking agent in the gel.

On simultaneous transport of water and solute through plant cell membranes: Evidence for the absence of solvent drag effect and insensitivity of the reflection coefficient

AbstractThe simultaneous efflux of tritiated water and 14C labelled ethanol from inner epidermal cells of the bulb scale of Allium cepa was measured with a specially designed efflux chamber. It was found that water and ethanol moved essentially independently. Rates of efflux of tritiated water and 14C ethanol were essentially the same in the presence or absence of a simultaneous influx of water.Using the same technique the efflux of tritiated water from the epidermal cells was measured during a simultaneous flow of nonlabelled ethanol. When tritiated water and ethanol moved in opposite directions, the water permeability values became slightly reduced depending upon the concentration of ethanol. When ethanol and tritiated water moved in the same direction, however, no effect on water permeability values could be detected. These results are best explained by the molecular theory of diffusion across lipid bilayer membranes, and are consistent with the above findings of lack of interaction between water and ethanol as they are transported across the cell membrane.In another study, the solute permeability coefficients (Ks) for non‐electrolytes such as urea and methyl urea were measured by plasmolyzing the epidermal cells and transferring them to equimolal solutions of urea and methyl urea. This method was also used to measure the reflection coefficient (σ) for these nonelectrolytes. The Ks values for methyl urea were 16 times greater than the ones for urea. The values of σ for both of these solutes, however, were very close to 1.Using the Ks data available in the literature for the subepidermal cells of the Pisum sativum stem basis, the σ values were calculated for malonamide, glycerol, methyl urea, ethyl urea, dimethyl urea, and formamide. Again the Ks values for these nonelectrolytes varied by several orders of magnitude, whereas all σ values were found to be close to 1.These findings point out that σ is an insensitive parameter and that Ks, the solute permeability constant, has to be used for characterizing solute transport through the membrane. The present study shows that fast (e.g. ethanol, formamide) as well as slowly permeating molecules do not interact with water as they are transported across the cell membrane. Aqueous pores for the simultaneous transport of water and solutes, therefore, are absent in the plant cell membranes investigated here.

Effect of selected amides on heat-induced changes in milk

SummaryThe effect of 15 amides and related compounds on the heat stability of milk was investigated; of these urea, biuret, triuret, methyl urea and ethyl urea had a similar stabilizing effect. These 5 compounds reacted with lysine to form a ninhydrin-positive compound, possibly homocitrulline, and with lactose produced Maillard-type browning, but some of the other compounds studied were also capable of participating in one or both of these reactions. The only effect which the 5 stabilizing amides had in common and which the other compounds did not share was a significant pH-buffering capacity in synthetic systems and in milk. It is suggested that urea exercises its stabilizing influence in milk principally through its ability to buffer the pH of the system during heating.

On the reactions of NaNO2 with ethyl urea in the presence and absence of ascorbic acid.

On the reactions of NaNO2 with ethyl urea in the presence and absence of ascorbic acid.

Chemistry of nitropyrroles

1. A study was made of the reactions of the dipotassium salt of trinitropropionaldehyde with formaldehyde and a primary amine, those examined being benzylamine, 2-aminoethanol, glycine ethyl ester, aniline, ammonia, hydrazine, ethylenediamine, and urea. 2. The reactions with benzylamine, 2-aminoethanol, and glycine ethyl ester led to the formation of the corresponding nitropyrrole derivatives: 1-benzyl-3,4-dinitropyrrole, 1-(2-hydroxyethyl)-3,4-dinitropyrrole [3,4-dinitropyrrole-1-ethanol], and ethyl 3,4-dinitropyrrole-1-acetate. In the case of ammonia, hydrazine, ethylenediamine, and urea the reaction did not go in the desired direction. 3. In the reaction with aniline two individual substances C16H13N3O2 and C13H11N3O2 were obtained; their structures were not determined. 4. It was shown that simple homologs of formaldehyde can be used in the reaction, namely acetaldehyde and propionaldehyde.