Interaction Of Ethylene Glycol Research Articles

Study on the interaction of ethylene glycol with trypsin: Binding ability, activity, and stability

The study of the structural changes and thermal stabilities of proteins in the presence of various co-solutes is a critical element of basic research, drug discovery, and development. Ethylene glycol (EG) is typically known to be poisonous and teratogenic, causing skeletal and external abnormalities as well as other disorders. At pH 8, the influence of EG on the structure and thermal stability of trypsin was investigated using a variety of spectroscopic techniques. Spectroscopic techniques, fluorescence spectroscopy, circular dichroism (CD), and molecular dynamics simulation studies were used to evaluate the binding reaction between ethylene glycol and trypsin in the current study. Circular dichroism, Trp fluorescence, and absorption tests demonstrated that EG has an effect on secondary and tertiary structures of trypsin, and it boosts the protein's thermal stability, which increases with increasing EG concentration. This contact occurs through a static quenching process, according to fluorescence spectroscopy data, and van der Waals contributions and hydrogen bonds were also important in binding ethylene glycol to trypsin. The ethylene glycol binding constant (Kb) and the number of binding sites (n) were calculated using fluorescence quenching data. Kinetic technique analysis displayed a decrease in trypsin activity in the presence of ethylene glycol. Also, circular dichroism results confirmed the conformation changes resulting from the binding of ethylene glycol to trypsin. Molecular dynamics simulation using RMSD was used to test the stability of the trypsin-ethylene glycol complex in this study. Molecular docking research revealed that EG interacts with trypsin amino acid residues via hydrogen bonding and van der Waals interactions.

The effective ethanol rate against the toxicity of ethylene glycol

Ethylene glycol (EG) is a toxic substance and EG metabolites cause metabolic acidosis. The major emphasis in this study is to get rid of the toxicity of EG before conversion to its metabolites. The interaction between ethylene glycol and ethanol has been studied using DFT (Density functional theory method). In ethylene glycol metabolites in the blood; Glycolic acid is more stable and gloxal less stable. The interaction of ethylene glycol with ethanol has been considered for ethylene glycol metabolism. Thermodynamic values obtained from ethylene glycol metabolites and ethanol were also analyzed. According to the analyst results of ethanol and ethylene glycol ratios; The maximum effective point is very stable in the blood and its solubility is determined at this rate. It is very important to determine the most appropriate rate in the prevention of toxicity. This study is an important study in terms of the use of ethanol in the prevention of toxicity of EG, the first of its rates and in terms of preventing the loss of time and substance.

Effects of Ethylene Glycol on the Structure and Stability of Myoglobin Using Spectroscopic, Interaction, and In Silico Approaches: Monomer Is Different from Those of Its Polymers.

Investigation of changes in thermal stabilities and structures of proteins in the presence of different co-solutes (ligands) is an integral part in the basic research, discovery, and development of drugs. Ethylene glycol (EG) is known to be toxic and causes teratogenic, inducing primarily skeletal and external malformations and other diseases. The effect of EG on the structure and thermal stability of myoglobin (Mb) was studied using various spectroscopic techniques at pH 7.0 and two different temperatures. As revealed by circular dichroism, Trp fluorescence, nano-DSF, and absorption (UV and visible) measurements, EG (i) has no significant effect on secondary and tertiary structures of Mb at 25 °C, and (ii) it decreases the thermal stability of the protein, which increases with increasing concentration of EG. As revealed by ANS (8-anilino-1-naphthalene sulfonic acid) fluorescence measurements, heat-induced denatured protein has newly exposed hydrophobic patches that bind to ANS. Isothermal titration calorimetry revealed that the interaction between EG and Mb is temperature dependent; the preferential interaction of EG is entropy driven at low temperature, 298 K (25 °C), and it is enthalpy driven at higher temperature, 343 K (70 °C). Molecular docking study showed that EG interacts with side chains of amino acid residues of Mb through van der Waals interactions and hydrogen bonding.

Performance of mixture of ethylene glycol and glycine in inhibiting methane hydrate formation

This study investigates synergistic hydrate inhibition performance of conventional thermodynamic hydrate inhibitors (THIs) combined with amino acids. For this purpose, hydrate-liquid-vapor equilibrium (HLVE) data for methane were measured in the presence of mixed ethylene glycol and glycine using 1:1 mixtures at concentrations of 1 wt% (0.5 wt% ethylene glycol +0.5 wt% glycine), 5 wt% (2.5 wt% ethylene glycol +2.5 wt% glycine), 10 wt% (5 wt% ethylene glycol +5 wt% glycine), 20 wt% (10 wt% ethylene glycol +10 wt% glycine), and 30 wt% (15 wt% ethylene glycol +15 wt% glycine) by the isochoric pressure search method. Thermodynamic inhibition efficiency has been investigated by observing the shifts in the hydrate equilibrium curves and trends of the calculated hydrate suppression temperatures at various concentrations and pressures. The results were also obtained for ethylene glycol, glycine and ionic liquids for comparison. An improving inhibition performance by mixing ethylene glycol and glycine was observed, indicating the potential of amino acids as inhibition synergists in hydrate exploitation, oil/gas transportation and flow assurance. Molar hydrate dissociation enthalpies were calculated by using the Clausius-Clapeyron equation and showed that the interaction of ethylene glycol and glycine has no impact on the hydrate structure.

Nanoheterogeneous Catalytic Cotransformation of Polyatomic Alcohols and Carbamides

The interaction of ethylene glycol and glycerol with carbamide in the presence of nanosized cobalt oxide obtained by the decomposition of cobalt(II) acetylacetonate in diphenyl ether is studied. The average size of the nanosized catalyst particles is 8–10 nm. The effect of nanoheterogeneous catalysis on the cyclocondensation of polyatomic alcohols with carbamide is investigated. A high capacity of the nanosized catalyst in this process is found 150 g(cyclic carbonate)/(g(catalyst) h), which is more than 100 times higher than the capacity of conventional catalysts.

Hydrogen production from ethylene glycol reforming catalyzed by Ni and Ni–Pt hydrotalcite-derived catalysts

In this work, we report a study of the steam reforming (SR) and the aqueous phase reforming (APR) of ethylene glycol (EG) with catalysts based on Ni, prepared from hydrotalcite-like compounds. The Pt–Ni bimetallic catalyst was synthesized using controlled techniques derived from Surface Organometallic Chemistry on Metals (SOMC/M). This methodology allows obtaining very well-defined active phases, with low atomic Pt/Ni bulk values (∼0.004) and a specific interaction between both metals.We demonstrate that in the APR of EG, in which the CO bond cleavage reactions are more favored than in SR, the Ni catalyst is more efficient than the bimetallic Pt–Ni. However, this Pt–Ni bimetallic catalyst is more active and selective to hydrogen in the SR at 450 °C.The interaction of ethylene glycol with the catalyst surface was studied combining diffuse reflectance infrared spectroscopy with mass spectrometry. Through these studies carried out on the Pt–Ni catalyst, we observed low stability of the formate and carboxylate intermediate species, which would explain its higher activity to produce H2 and CO2 through the water gas shift reaction.

Formation of alloys upon the simultaneous electrochemical deposition of gold and tin from ethylene glycol and aqueous electrolytes

An ethylene glycol (EG) solution containing Au(III) and Sn(IV) compounds, and conditions for the electrochemical deposition of Au–Sn alloy based on AuSn and Au5Sn intermetallics with total tin content of 30–55 at % are proposed. Fundamental difficulties of the deposition of alloys with high tin content, (including eutectic Au–Sn alloy) from aqueous electrolytes are revealed. It is determined via voltammetry that the simultaneous deposition of gold and tin from aqueous and EG electrolytes proceeds with the depolarization effect of both Au(III) and Sn(IV) as a result of the formation of the alloy, the increase in the rate of tin cathodic reduction being more noticeable in case of EG solution. Formation of SnCl2EG(H2O)2+ complex upon the dissolution of SnCl4 · 5H2O in glycol, the stability of the composition of tetracyanoaurate ions upon the dissolution of K[Au(CN)4], and the weakening of intermolecular interactions in EG with small amounts of water were revealed via IR spectroscopy. It is suggested that the depolarization effect is due not only to alloy formation, but also to the formation of SnCl2EG(H2O)2+ cations, their association with Au(CN)4- anions, and a change in the mechanism of Au(III) and Sn(IV) reduction.

Density, viscosity and spectroscopic studies of the binary system of ethylene glycol + dimethyl sulfoxide at T = (298.15 to 323.15) K

Densities and viscosities of the binary system of ethylene glycol (EG) (1)+dimethyl sulfoxide (DMSO) (2) over the entire composition range were measured at T=(298.15, 303.15, 308.15, 313.15, 318.15, and 323.15) K and atmospheric pressure. Based on density and viscosity data, the excess molar volume, viscosity deviation, excess Gibbs free energy of activation for the viscous flow, and apparent molar volumes were calculated. These results were fitted to a Redlich–Kister equation to obtain the coefficients and to estimate the standard deviations between the experimental and calculated quantities. Meanwhile, from the kinematic viscosity data, the enthalpy of activation for viscous flow and entropy of activation for the viscous flow were also calculated. In addition, based on UV–vis and FTIR spectral results, the intermolecular interaction of EG with DMSO was discussed.

Effects of functionalization of carbon nanotubes on their dispersion in an ethylene glycol-water binary mixture--a molecular dynamics and ONIOM investigation.

The present work utilizes classical molecular dynamics simulations to investigate the covalent functionalization of carbon nanotubes (CNTs) and their interaction with ethylene glycol (EG) and water molecules. The MD simulation reveals the dispersion of functionalized carbon nanotubes and the prevention of aggregation in aqueous medium. Further, residue-wise radial distribution function (RRDF) and atomic radial distribution function (ARDF) calculations illustrate the extent of interaction of -OH and -COOH functionalized CNTs with water molecules and the non-functionalized CNT surface with EG. As the presence of the number of functionalized nanotubes increases, enhancement in the propensity for the interaction with water molecules can be observed. However, the same trend decreases for the interaction of EG molecules. In addition, the ONIOM (M06-2X/6-31+G**:AM1) calculations have also been carried out on model systems to quantitatively determine the interaction energy (IE). It is found from these calculations that the relative enhancement in the interaction of water molecules with functionalized CNTs is highly favorable when compared to the interaction of EG.

Manifestation of Intermolecular Interactions in Raman Spectra and ab Initio Calculations of Molecular Aggregation in Liquid Ethylene Glycol

We present the results of a study of intermolecular interactions in ethylene glycol by Raman spectra. For a more reasonable assumptions about the possibility of the existence of aggregated intermolecular complexes and monomeric molecules of ethylene glycol in the liquid, as well as manifestations of these formations in spectra, we carried out ab initio calculations of the normal vibration frequencies, depolarization ratios of bands, formation energy, and other physical and optical characteristics for aggregated complexes of molecules. Calculations were carried out in the framework of a self-consistent field (RHF) using the basis 6-31G++(d, p) with full optimization of the geometry of molecules. Calculations showed a possibility of the formation of an intermolecular H-bond between the H atom of the O–H group of one molecule and the O atom of another molecule. For a dimeric aggregate, the intermolecular H-bond length is 1.986 ˚ A. In molecules of the dimer, there is a slight change of bonds’ lengths, but also there is a significant change of the charge distribution between atoms. The energy of dimer formation is 4.6 kcal/mole, the dipole moment of an aggregate is 6.35 D (in the monomeric molecule, the dipole moment is 2.73 D). In Raman spectra, there are some features of the manifestation of the H-bonding between molecules: asymmetry of bands and splitting of bands that are the features that accompany the H-bond formation.

Adsorption and conversion of ethylene glycol on the surface of Ag-containing catalyst modified with phosphate

The interaction of ethylene glycol with the surface of Ag-containing catalysts modified with phosphates was studied by IR spectroscopy. It was found that ethylene glycol was adsorbed at the surface phosphate groups; the presence of water vapor increased the stability of adsorbed ethylene glycol to a temperature of 400°C. A study of the kinetics of oxidation of ethylene glycol showed that it was consecutively converted into glycolaldehyde and glyoxal at 400°C. At 500–550°C, glyoxal was formed upon both the consecutive and direct conversion of ethylene glycol. The presence of a stage of the consecutive conversion of ethylene glycol into glycolaldehyde and glyoxal was caused by the participation of surface phosphate groups in the adsorption of alcohol molecules to be oxidized.

A Comparative Study of the Electrooxidation of Ethylene Glycol on Transition Metal Electrodes in Alkaline Solution

Electrodes made of group VIII and IB metals were examined for their redox process and electrocatalytic activities towards the oxidation of ethylene glycol in alkaline solutions. The method of cyclic voltammetery (CV) and Open circuit potentials measurement (OCP) was employed. It is found that considerable electrooxidation current are observed for silver and copper but lower anodic overpotential for oxidation is obtained for gold and platinum. Oxide layer produced on the surface of all electrodes in alkaline solution under anodic scan participates in ethylene glycol electrooxidation. Oxidation current observed in the reverse scans for platinum and gold are higher than those observed in forward potential scan. Open circuit potential measurements have shown the interaction of ethylene glycol and electrodes.

Weak Intramolecular Interactions in Ethylene Glycol Identified by Vapor Phase OH−Stretching Overtone Spectroscopy

Vapor phase OH-stretching overtone spectra of ethylene glycol were recorded to investigate weak intramolecular hydrogen bonding. The spectra were recorded with conventional absorption spectroscopy and laser photoacoustic spectroscopy in the first to fourth OH-stretching overtone regions. The room-temperature spectra are dominated by two conformers that show weak intramolecular hydrogen bonding. A less abundant third conformer, with no sign of hydrogen bonding, is also observed. Vapor phase spectra of the ethylene-d(4) glycol isotopomer were also recorded and used to identify an interfering resonance between CH-stretching and OH-stretching states in the fourth overtone. Anharmonic oscillator local mode calculations of the OH-stretching transitions have provided an accurate simulation of the observed spectra. The local mode parameters were calculated with coupled cluster ab initio methods. The calculations facilitate assignment of the different conformers in the spectra and illustrate the effect of the intramolecular hydrogen bonding.

Ethylene glycol electrooxidation on carbon supported Pt, PtRu and Pt 3Sn catalysts—A comparative DEMS study

We present results of a comparative study on the interaction of ethylene glycol (EG) with carbon supported Pt, PtRu and Pt 3Sn nanoparticle catalysts, employing electrochemical and quantitative differential electrochemical mass spectroscopy (DEMS) measurements under continuous reaction and continuous electrolyte flow conditions. For all three catalysts EG adsorption is inhibited at very cathodic adsorption potentials, dissociative adsorption starts above 0.06 V and increases with increasing potential. Based on the electron yield per formed CO 2 molecule and on the similarity with the CO ad stripping characteristics CO ad is identified as the main stable adsorbate; the relative coverage in terms of adsorbed C1 species, relative to that of a saturated CO adlayer on the respective catalyst, reaches a maximum of ca. 0.6 at around 0.4 V on Pt/Vulcan, ca. 0.2 at around 0.2 V on PtRu/Vulcan and ca. 0.4 at around 0.35 V on Pt 3Sn/Vulcan. Bulk EG electrooxidation under steady-state conditions shows a very small current efficiency for CO 2 formation of below 6% for 0.1 M EG on all three catalysts, the oxidation of EG mainly generates partly oxidized C2 by-products. Catalyst modification by Ru or Sn improves the activity for EG oxidation at low potentials (≤0.56 V), but does not lead to better selectivities for complete EG oxidation to CO 2 at potentials with significant oxidation rates. Hence, C–C bond breaking is rate limiting for complete oxidation under present reaction conditions for all three catalysts. The data are consistent with a parallel pathway reaction mechanism, with formation and subsequent oxidation of CO ad in the one pathway and partial oxidation, via a sequence of reaction steps, to increasingly oxidized C2 species in the other pathway.

Investigation by dielectric spectroscopy of domain motions in lysozyme: effect of solvent and binding of inhibitors

Recently, we have shown that ethylene-glycol, a co-solvent commonly used in studying protein folding, strongly affects the dielectric response of lysozyme. The data were coherently interpreted hypothesizing that glycol molecules wedges between and separates the two domains of lysozyme making them rotationally independent. In this Letter, we describe a new dielectric experiment on lysozyme in water/ethylene-glycol solutions in the presence of N-acetyl- d-glucosammine, a well known inhibitor for the protein. The results indicate that the interaction of ethylene-glycol with the protein is markedly influenced by NAG, in the sense that the saccharide preferentially links with lysozyme driving away the glycol molecules.

Asymmetric synthesis of 3β-acetoxy-17, 17-ethylendioxy-15β, 16β-methylene-5-androsten-7β-ol

3β-acetoxy-17, 17-ethylendioxy-15β, 16β-methylene-5-androsten-7β-ol(I) was prepared by 3 steps from 3β-acetoxy-15β, 16β-methylene-5-androsten-17-one (II) with overall yield of 52.7%. Thus, interaction of ethylene glycol and material (II) gave 3β-acetoxy- 17, 17-ethylendioxy-15β, 16β-methylene-5-androsten (III) which was subsequently oxidated and stereoselectively reduced to produce compound(I). The normal influencing factors, such as the types of oxidants and reductives, the mole ratio of reactants, the reaction temperature, and the addition ways of reactants, in oxidation and reduction were discussed. The results show that the oxidation rate order is CrO3-C5H5N (1:1, mole fraction)>CrO3-C5H5N(1:2)>(C5H5NH)2Cr2O7 in terms of the oxidant, the yield of the oxidation becomes higher with increasing the oxidant stoichiometry and raising the reaction temperature. And the optimum condition is that the reaction temperature is at 30 °C, and n(III)/n(CrO3-C5H5N(1:2))=1:20. The yield of the −7β alcohol order with Li[Al(OC(CH3)3)3H] (e. g. 78.6%) is more than that with NaBH4 (e. g. 14.5%) in terms of the reductive agent and the reduction rate decreases in the course of reaction. The compound (I) is characterized by IR and MS.

Influence of Polyethylene Glycols on the Percolation Behavior of Anionic and Nonionic Water-in-Oil Microemulsions

Replacing a proportion of water by oligo- and polyethylene glycols (PEGs) in water-in-oil (w/o) microemulsions strongly affects the phase boundaries and the percolation behavior of these systems. The influence of ethylene glycol (EG) and PEG on systems stabilized by ionic Aerosol OT (AOT) and nonionic Igepal CO-520 (IG) surfactants is examined using electric conductivity and time-resolved electric birefringence (Kerr-effect) measurements. Addition of ethylene glycol induces percolation in AOT microemulsions but stabilizes droplets in IG systems. This effect of EG is contrary to almost all other solutes, stabilizing the same structure in ionic and nonionic systems. It can be understood by the different interaction of EG with the solvated polar headgroups of AOT and IG respectively. Regarding the molecular weight dependence one can distinguish three regimes in the AOT system: Small oligoethylene glycols induce percolation, medium size polymers increasingly stabilize droplets, and for a degree of polymeriza...

Interaction of ethylene glycol with alumina supported copper —an FTIR study

AbstractThe adsorption of ethylene glycol on γ‐alumina as well as on an alumina‐supported copper catalyst has been studied under working conditions using transient FTIR experiments. Time‐dependent spectra were recorded after exposure of the substrates to a pulse of ethylene glycol, or to subsequent stepwise increases in the ethylene glycol concentration. On alumina both dehydration and dehydrogenation products were observed; on supported copper dehydration was suppressed and only the aldehyde formed by dehydrogenation of the reactant glycol was observed. Hydrogen was found to prevent the formation of dialdehydic species (surface bound glyoxal) which were observed in nitrogen carrier gas. The relevance of these results to the mechanism of the copper‐catalyzed amination of alcohols is discussed.

Intermediate chromium(V) complex species and their role in the process of chromium(VI) reduction by ethylene glycol

The interaction of ethylene glycol with potassium dichromate is studied at 80° in pseudo first-order conditions by ESR method, monitoring the formation of Cr V and Cr III. The formation of Cr V complex with ethylene glycol was observed and its kinetics studied. The kinetic data show, that Cr V is produced as a result of the reaction Cr IV+Cr VI→2Cr V. Water has a strong influence on the reaction as in its presence the process 3Cr V→2Cr VI+Cr III takes place. If the reaction is carried out at a low pressure and water formed in the reaction course removed, the current Cr V concentration i srelatively high and the Cr V complex with ethylene glycol stabilized for several days at room temperature. The final products of ethylene glycol oxidation are water and glycol aldehyde, no cleavage reaction being found to proceed in these conditions.

Solvophobic interactions and micelle formation in structure forming nonaqueous solvents.

HYDROPHOBIC interactions are important in maintaining the conformations of proteins and various macromolecules. The free energies of these interactions are entropic in origin, for the enthalpy changes are actually unfavourable at low temperatures (ΔH>0). It is generally believed that around the nonpolar parts of the solutes in contact with water there is an increased ordering1–3 of the water molecules as a result of hydrogen bonding, and that on the formation of the hydrophobic bond this order is diminished so that there is a positive entropy change. We have recently shown4 that there are solvophobic interactions in ethylene glycol, a polar nonaqueous solvent, chiefly on the grounds of the formation of micelles by several cationic detergents and the limited solubility of hydrocarbons in this solvent.