Hydrophobic free energy for protein folding is currently measured by liquid-liquid transfer, based on an analogy between the folding process and the transfer of a nonpolar solute from water into a reference solvent. The second part of the analogy (transfer into a nonaqueous solvent) is dubious and has been justified by arguing that transfer out of water probably contributes the major part of th...

In this research, Quantum-mechanical calculations were performed at the HF method with the 6-31+G*basis set and at the B3LYP method with the 6-31+G* basis set in the gas phase and five solvents such as water, DMSO, methanol, ethanol and dichloromethane at six temperatures. According to these theoretical results of IR, we extracted thermo chemical parameters such as enthalpy (∆H Kcal/mol), Gibbs...

The hydrophobic part of the solvent-accessible surface of a typical monomeric globular protein consists of a single, large interconnected region formed from faces of apolar atoms and constituting approximately 60% of the solvent-accessible surface area. Therefore, the direct delineation of the hydrophobic surface patches on an atom-wise basis is impossible. Experimental data indicate that, in a...

in this work, a procedure for preconcentration of cobalt using dispersive liquid–liquid microextraction (dllme) with the reagent 1-nitroso 2-naphtol as complexing reagent was developed. at ph 4, co(ii) was complexed with 1-nitroso 2-naphtol and extracted into the fine droplets formed when mixing chloroform (extraction solvent), ethanol (disperser solvent) and the sample solution. after extracti...

in this work, a procedure for preconcentration of silver using dispersive liquid–liquid microextraction with the reagent dithizone as complexing reagent was developed. at ph 2, silver ions are complexed with dithizone and extracted into the fine droplets formed when mixing carbon tetrachloride (extraction solvent), ethanol (disperser solvent) and the sample solution. after extraction, the phase...

This review illustrates how water, as an environmentally friendly solvent, can have significant additional benefits when it is used as a solvent for the Diels–Alder reaction. The mechanism by which the unique properties of water enhance the rate and selectivity are discussed. Also, possibilities for the achievement of further increases in rate and enantioselectivity of aqueous Diels–Alder react...

some 2-iminothiazolidin-4-ones have been synthesized by the reaction of dialkyl acetylenedicarboxylates with thiosemicarbazones. the reaction was performed in the presence of 10 mol% of triphenylphosphine and tetrabutylammonium bromide as a phase transfer catalyst in water as a green solvent. all the synthesized compounds were characterized by their physical and spectral data.

The permeation of different organic molecules in water solvent and in 12% ethanolwater solution by hydrophilic reverse osmosis membrane was studied. The membrane was conditioned to the ethanol-water solution before the experiments. Initially, the membrane was characterized by water and ethanol-water solutions. The permeation of four solutes (tyramine, proline, glucose and tartaric acid) showed ...

In the present work we study and compare unfolding of a small protein, chicken villin headpiece (HP-36) in two different aqueous binary mixtures, namely water-ethanol (EtOH) and water-dimethyl sulphoxide (DMSO). In both the binary mixtures, HP-36 is found to unfold (fully or partially, depending on the mixture) under ambient conditions, that otherwise requires temperature as high as ~600 K to d...

Mean spherical approximation (MSA) for electrolyte solution has been extended to investigate the role of partial solvent polarization densities around an ion in a completely asymmetric binary dipolar mixture. The differences in solvent diameters, dipole moments, and ionic size are incorporated systematically within the MSA framework in the present theory for the first time. In addition to the c...