Protein folding is subject to the effects of solvation environment. A variety of organic solvents are used as additives for in vitro refolding of denatured proteins. Examination of the solvent effects on protein folding could be of fundamental importance to understand the molecular interactions in determining protein structure. This article investigated the folding of α-helix and β-hairpin stru...

The solubility of amino acids and the preferential solvent interaction of hen-egg lysozyme in acetonitrile (AN)-water mixtures (<60 w/v% AN) were investigated by means of densimetric and refractometric methods at 25 degreesC. The free energy of transfer from water to aqueous AN was negative for most nonpolar side-chains of amino acids and positive for the peptide group, the extent being compara...

The dynamics and conformational landscape of proteins in organic solvents are events of potential interest in nonaqueous process catalysis. Conformational changes, folding transitions, and stability often correspond to structural rearrangements that alter contacts between solvent molecules and amino acid residues. However, in nonaqueous enzymology, organic solvents limit stability and further a...

First-order rate coefficients have been obtained for the solvolysis of triethyloxonium hexafluorophosphate in a variety of organic and aqueous-organic solvents. These have been used to set up a scale of solvent nucleophilicities based upon the four-parameter (two-term) Grunwald-Winstein equation. The required corrections for variation in solvent influence upon the leaving group were estimated f...

In this study, solvent-free and phase transfer catalysis conditions coupled with microwave irradiation and their advantages in synthesis of N-alkylation of primary anilines were reported. In this way two different microwave processing techniques were compared in terms of reaction yields. Consequently, microwave irradiation significantly reduced reaction times compared to traditional heating met...

Catalysis in organic solvents and the mapping of protein surfaces using multiple solvent crystal structures are two rapidly developing areas of research. Recent advances include the study of protein folding and stability in different solvents, and the demonstration that it is possible to qualitatively rank the affinities of protein binding sites for a given organic solvent using the multiple so...

A supercritical fluid can be used in substitution of the original organic solvent for the preparation of pharmaceutical forms. The steps involved in the preparation are essentially similar to those of the traditional preparation but in this case the final purification is not required. The interest in the supercritical fluid impregnation of polymeric materials stems from the opportunity to utili...

When adult worms of the acanthocephalan parasite, Polymorphus minutus, are incubated for 4 hr. at 417 ±0-5° C. under near-anaerobic conditions in a balanced salt solution containing radioactive glucose, they excrete two substances which contain approximately equal amounts of radioactivity. It was suspected that these metabolites might be organic acids. They were found to be non-volatile, dialys...

Two types of photoinitiator are considered: (1) transition metal complexes (mainly carbonyls), (2) chelates of transition metals. In systems of type (1) the metal is in a low oxidation state and an organic halide is generally, but not always, present; on thc other hand, in (2) the metal is initially in a high oxidation state. Comparison between photoand thermal-initiation is made for each type....

a highly efficient and simple method for the preparation of α,α´-bis(arylidene)cycloalkanones under solvent-free conditions has been developed. the crossed-aldol condensation of cycloalkanones (1 eq.) with arylaldehydes (2 eq.) in the presence of 2.5 mol% of ionic liquid 1,3-disulfonic acid imidazolium hydrogen sulfate {[dsim]hso4} afforded the title compounds in high yields and short reaction ...