Effect of dimethyl sulfoxide, urea, guanidine hydrochloride, and sodium chloride on hydrophobic interactions. Heats of dilution of tetrabutylammonium bromide and lithium bromide in mixed aqueous solvent systems

1972 ◽  
Vol 76 (21) ◽  
pp. 3050-3057 ◽  
Author(s):  
Martin J. Mastroianni ◽  
M. J. Pikal ◽  
Siegfried Lindenbaum
Keyword(s):  
Sodium Chloride ◽  
Dimethyl Sulfoxide ◽  
Hydrophobic Interactions ◽  
Guanidine Hydrochloride ◽  
Tetrabutylammonium Bromide ◽  
Lithium Bromide ◽  
Heats Of Dilution ◽  
Aqueous Solvent ◽  
Solvent Systems

Thermodynamics and acoustic effects of quercetin on micellization and interaction behaviour of CTAB in different hydroethanol solvent systems

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Vikrant Abbot ◽  
Poonam Sharma
Keyword(s):  
Pharmaceutical Industry ◽  
Hydrophobic Interactions ◽  
Chemical Properties ◽  
Formulation Development ◽  
Surfactant Interactions ◽  
Physico Chemical ◽  
Ultrasonic Sound ◽  
Apparent Molar Compressibility ◽  
Solvent Systems ◽  
Thermoacoustic Properties

AbstractFlavonoids amongst the class of secondary metabolites possess numerous health benefits, are known for its use in pharmaceutical industry. Quercetin, a flavonoid has more prominent medical advantages however its utilization is constrained because of various instability and insolubility issues and therefore, taken into consideration for studying its physico-chemical properties. In view of that, the thermodynamic and thermoacoustic properties of quercetin were examined in presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) at different hydroethanolic concentrations and temperatures. The conductivity studies were used to calculate change in enthalpy (∆Hom), change in entropy (∆Som) and change in Gibbs free Energy (∆Gom) of micellization. The interactions between quercetin and CTAB were found to be endothermic, entropically controlled and spontaneous. Further, ultrasonic sound velocity and density studies were carried out and utilized for the calculation of thermoacoustic parameters i.e. apparent molar volume and apparent molar compressibility. Thermoacoustic properties revealed that at higher surfactant concentration, hydrophobic interactions are dominant. The results suggested that the flavonoid-surfactant interactions in hydroethanolic solutions is more favourable as compared with aqueous solution. Overall, the data is favourable for the framework to be used for detailing advancement, drug development, drug industry, pharmaceutical industry, medical administration and formulation development studies.

scholarly journals Characterization of Virus Adsorption by Using DEAE-Sepharose and Octyl-Sepharose

2002 ◽  
Vol 68 (8) ◽  
pp. 3965-3968 ◽  
Author(s):  
Patricia A. Shields ◽  
Samuel R. Farrah
Keyword(s):  
Sodium Chloride ◽  
Electrostatic Interactions ◽  
Hydrophobic Interactions ◽  
Chloride Concentration ◽  
Sodium Chloride Concentration ◽  
Virus Adsorption ◽  
Nacl Concentration

ABSTRACT Viruses were characterized by their adsorption to DEAE-Sepharose or by their elution from octyl-Sepharose by using buffered solutions of sodium chloride with different ionic strengths. Viruses whose adsorption to DEAE-Sepharose was reduced most rapidly by an increase in the sodium chloride concentration were considered to have the weakest electrostatic interactions with the solids; these viruses included MS2, E1, and φX174. Viruses whose adsorption to DEAE-Sepharose was reduced least rapidly were considered to have the strongest electrostatic interactions with the column; these viruses included P1, T4, T2, and E5. All of the viruses studied adsorbed to octyl-Sepharose in the presence of 4 M NaCl. Viruses that were eluted most rapidly following a decrease in the concentration of NaCl were considered to have the weakest hydrophobic interactions with the column; these viruses included φX174, CB4, and E1. Viruses that were eluted least rapidly from the columns after the NaCl concentration was decreased were considered to have the strongest hydrophobic interactions with the column; these viruses included f2, MS2, and E5.

scholarly journals STUDIES ON THE POSTERIOR SILK GLAND OF THE SILKWORM BOMBIX MORI

1970 ◽  
Vol 46 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Yutaka Tashiro ◽  
Eiichi Otsuki
Keyword(s):  
Guanidine Hydrochloride ◽  
Lithium Bromide ◽  
Posterior Part ◽  
Silk Gland ◽  
Sedimentation Equilibrium ◽  
Partial Specific Volume ◽  
Anterior Portion ◽  
Equilibrium Analyses ◽  
Fibroin Solution ◽  
Posterior Silk Gland

Ultracentrifugal analyses of the native silk proteins extracted from the various parts of the middle silk gland of the mature silkworm have revealed that there exist four components with S°20,w values of 10S, 9–10S, 9S, and 4S in the extract. It is suggested that the fastest 10S component is the native fibroin synthesized in the posterior silk gland and transferred to the middle silk gland to be stored there, while the slower three components probably correspond to inner, middle, and outer sericins which were synthesized in the posterior, middle, and anterior portion of the middle silk gland, respectively. Native fibroin solution was prepared from the most posterior part of the middle silk gland. Ultracentrifugal analyses have shown that the solution contains considerable amounts of aggregates in addition to the main 10S component. Treatment with lithium bromide (LiBr), urea, or guanidine hydrochloride solution up to 6 M all have failed to dissociate the 10S component. From the sedimentation equilibrium analyses and partial specific volume of 0.716, the molecular weight of the 10S component of the native fibroin solution was found to be between 3.2 – 4.2 x 105, with a tendency to lie fairly close to 3.7 x 105.

Oxidation of lignans and lignin model compounds by laccase in aqueous solvent systems

2011 ◽  
Vol 72 (3-4) ◽  
pp. 122-129 ◽  
Author(s):  
Maija-Liisa Mattinen ◽  
Pekka Maijala ◽  
Paula Nousiainen ◽  
Annika Smeds ◽  
Jussi Kontro ◽  
...  
Keyword(s):  
Model Compounds ◽  
Lignin Model Compounds ◽  
Aqueous Solvent ◽  
Lignin Model ◽  
Solvent Systems

Salt effects on adsorbed nonelectrolytes

1977 ◽  
Vol 55 (23) ◽  
pp. 4018-4027 ◽  
Author(s):  
Robert Aveyard ◽  
Syed M. Saleem
Keyword(s):  
Aqueous Solution ◽  
Surface Effect ◽  
Hydrophobic Interactions ◽  
Tetrabutylammonium Bromide ◽  
Inorganic Salts ◽  
Salt Effects ◽  
Salting Out ◽  
Oh Groups ◽  
Solution Interface ◽  
Alkyl Groups

An approach to the study of the influence of electrolytes on adsorbed nonelectrolytes at liquid surfaces is described. The adsorption of tetrabutylammonium bromide (Bu4NBr) from aqueous solution to the interfaces with octane, decanol, and air has been determined. Results are presented for the effects of some inorganic salts (NaCl, NH4Br, and Na2CO3), and of Bu4NBr on monolayers of butanol at the air – aqueous solution interface, and of Bu4NBr on dodecanol adsorbed at the octane – aqueous solution interface. The interfacial salt effects differ from the bulk effects in the cases studied. The inorganic salts, which salt-out butanol (and alkanols generally) in aqueous solution, have little or no effect on adsorbed butanol. On the other hand, Bu4NBr which salts-in alkanols in bulk aqueous solution has a strong salting-out effect on dodecanol at the liquid–liquid interface; a similar but less marked effect is observed for butanol at the liquid–vapour surface. Salting-in of alkanols by Bu4NBr in bulk has previously been ascribed to hydrophobic interactions between cations and alkyl groups of the alkanol, whereas the surface effect is assumed to result from interactions between alcoholic OH groups and cations.

Sign in / Sign up

Export Citation Format

Share Document