Ultrasonic and thermodynamic studies of tetracyclines in solutions

The ultrasonic velocity, U, density, and viscosity of aqueous and non-aqueous (water + dioxan) solutions of tetracycline hydrochloride and chlorotetracycline have been measured at two different temperatures. Partial molal volumes, [Formula: see text] partial molal compressibility, [Formula: see text], Vand's interaction coefficients, Q and C, and thermodynamic activation parameters ΔG*, ΔS*, and ΔH* of these solutions have been computed from the ultrasonic velocity, density, and viscosity data. The results are interpreted in terms of solute–solvent interaction.

Download Full-text

Study of Thermodynamic and Transport Properties of Glycine, Diglycine, and Triglycine in Aqueous Tartrazine at Different Temperatures

Zeitschrift für Naturforschung A ◽

10.1515/zna-2009-1113 ◽

2009 ◽

Vol 64 (11) ◽

pp. 758-764 ◽

Cited By ~ 8

Author(s):

Anwar Ali ◽

Rajan Patel ◽

Shahjahan Khan ◽

Vidiksha Bhushan

Keyword(s):

Viscous Flow ◽

Activation Parameters ◽

Partial Molar Volumes ◽

Molar Refraction ◽

Viscosity Data ◽

Molar Volumes ◽

Viscosity Coefficients ◽

Different Temperatures ◽

Refractive Index Data ◽

Amino Acid Glycine

The densities (ρ), viscosities (η), and refractive indices (nD) of (0.01, 0.05, 0.10, 0.15, and 0.20 m) amino acid, glycine, and peptides, diglycine and triglycine in 0.01 m aqueous tartrazine solution were determined at 288.15, 293.15, 298.15, 303.15, 308.15, and 313.15 K. The density data were utilized to evaluate apparent molar volumes (φv) which, in turn, were used to determine partial molar volumes (φv ◦) using Masson’s equation. The transfer volumes were also calculated. The viscosity data were analyzed using the Jones-Dole equation to determine the viscosity coefficients and the activation parameters. The activation parameters of viscous flow were obtained to throw light on the mechanism of viscous flow. The molar refraction was calculated using the refractive index data. The results were interpreted in the light of ion-ion, ion-nonpolar, and nonpolar-nonpolar interactions and the effect of increasing hydrophobicity as we move from glycine to triglycine on these interactions in presence of the dye tartrazine was also investigated.

Download Full-text

Ultrasonic Study of Substituted Thiazoles at Different Temperatures

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.61.105 ◽

2015 ◽

Vol 61 ◽

pp. 105-109 ◽

Cited By ~ 1

Author(s):

A.B. Naik

Keyword(s):

Ultrasonic Velocity ◽

Adiabatic Compressibility ◽

Effect Of Temperature ◽

Water Mixture ◽

Excellent Correlation ◽

Acoustical Parameters ◽

Temperature Variations ◽

Solvent Interaction ◽

Pure Solvent ◽

Different Temperatures

Density, ultrasonic velocity of pure solvent, dimethylformamide (DMF) and ligand solutions of substituted thiazoles in DMF-water mixture were measured at different temperatures (303.15, 308.15, 313.15 and 318.15) K. Acoustical parameters such as adiabatic compressibility, intermolecular free length, acoustical impedance and relative association were determined from experimental data of density and ultrasonic velocity. The effect of temperature variations on the strength of molecular interaction has also been studied. An excellent correlation represents in terms of solute-solvent and solvent-solvent interaction at all temperatures.

Download Full-text

Effect of KCl and KNO3 on Partial Molal Volumes and Partial Molal Compressibilities of Some Amino Acids at Different Temperatures

International Journal of Thermophysics ◽

10.1007/s10765-008-0514-x ◽

2008 ◽

Vol 30 (2) ◽

pp. 475-489 ◽

Cited By ~ 16

Author(s):

Riyazuddeen ◽

Imran Khan

Keyword(s):

Amino Acids ◽

Partial Molal Volumes ◽

Different Temperatures ◽

Molal Volumes

Download Full-text

Effects of temperature on measurement of aspartate aminotransferase and alanine aminotransferase in commercial control sera.

Clinical Chemistry ◽

10.1093/clinchem/32.1.184 ◽

1986 ◽

Vol 32 (1) ◽

pp. 184-185 ◽

Cited By ~ 2

Author(s):

J C Hafkenscheid ◽

B E Kohler

Keyword(s):

Aspartate Aminotransferase ◽

Alanine Aminotransferase ◽

Activity Concentration ◽

Activation Parameters ◽

Thermodynamic Activation Parameters ◽

Activity Concentrations ◽

Different Temperatures ◽

Human Sera ◽

Proportional Increase ◽

Effects Of Temperature

Abstract The catalytic activity concentrations of aspartate aminotransferase (EC 2.6.1.1) and alanine aminotransferase (EC 2.6.1.2) in several commercial control sera were determined at three different temperatures. Although these sera were of various biological origins, the temperature-conversion factors calculated are nearly identical to those for native human sera. The proportional increase of the activity concentration caused by adding pyridoxal-5'-phosphate to the reaction mixture is independent of the reaction temperature. Arrhenius plots and some thermodynamic activation parameters of both enzymes are independent of the presence of the coenzyme pyridoxal-5'-phosphate.

Download Full-text

SEASONAL CHANGES IN THERMODYNAMIC ACTIVATION PARAMETERS OF MYOSIN Ca2+ ATPase FROM GRASS CARP AND SILVER CARP

Acta Hydrobiologica Sinica ◽

10.3724/sp.j.1035.2008.00161 ◽

2008 ◽

Vol 32 (2) ◽

pp. 161-166

Author(s):

Li HAN

Keyword(s):

Grass Carp ◽

Seasonal Changes ◽

Silver Carp ◽

Activation Parameters ◽

Thermodynamic Activation Parameters

Download Full-text

Kinetic Studies of [4n+2]π-Thermal Cyclodimerization of 1-(3-Pyridazinyl)-3-oxidopyridinium Betaines

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19921951 ◽

1992 ◽

Vol 57 (9) ◽

pp. 1951-1959 ◽

Cited By ~ 2

Author(s):

Madlene L. Iskander ◽

Samia A. El-Abbady ◽

Alyaa A. Shalaby ◽

Ahmed H. Moustafa

Keyword(s):

Energy Gap ◽

Activation Parameters ◽

Kinetic Studies ◽

Cyclic Transition ◽

Concerted Mechanism ◽

First Order ◽

Thermodynamic Activation Parameters ◽

Cyclic Transition State ◽

Complete Dissociation ◽

Homo Lumo

The reactivity of the base induced cyclodimerization of 1-(6-arylpyridazin-3-yl)-3-oxidopyridinium chlorides in a pericyclic process have been investigated kinetically at λ 380 nm. The reaction was found to be second order with respect to the liberated betaine and zero order with respect to the base. On the other hand dedimerization (monomer formation) was found to be first order. It was shown that dimerization is favoured at low temperature, whereas dedimerization process is favoured at relatively high temperature (ca 70 °C). Solvent effects on the reaction rate have been found to follow the order ethanol > chloroform ≈ 1,2-dichloroethane. Complete dissociation was accomplished only in 1,2-dichloroethane at ca 70 °C. The thermodynamic activation parameters have been calculated by a standard method. Thus, ∆G# has been found to be independent on substituents and solvents. The high negative values of ∆S# supports the cyclic transition state which is in favour with the concerted mechanism. MO calculations using SCF-PPP approximation method indicated low HOMO-LUMO energy gap of the investigated betaines.

Download Full-text

Viscosity of Diluted Aqueous K2CO3/KHCO3 Solutions

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19921879 ◽

1992 ◽

Vol 57 (9) ◽

pp. 1879-1887 ◽

Cited By ~ 4

Author(s):

Zdeněk Palatý

Keyword(s):

Dynamic Viscosity ◽

Correlation Equation ◽

Viscosity Data ◽

Electrolyte Mixtures ◽

Interaction Coefficients ◽

Basic Solutions ◽

Good Agreement

The applicability of the equation derived for calculating the dynamic viscosity of ternary non-electrolyte mixtures, to the correlation of viscosity data of the H2O- K2CO3/KHCO3 system is verified in this work. It was found out that the values of dynamic viscosity obtained experimentally are in good agreement with the viscosity values calculated from this equation. The equation constants - interaction coefficients - were determined from the measurements of dynamic viscosity on mixing the basic solutions of K2CO3 and KHCO3 of known concentration. The correlation equation makes it possible to calculate viscosity of the K2CO3/KHCO3 solutions in the K2CO3 and KHCO3 concentration range from 0 to about 2.0 kmol m-3.

Download Full-text

Conductance and Viscometric Studies of Some Tetraalkylammonium and Sodium Salts in Acetonitrile-Dimethyl Sulfoxide Mixtures at 35 °C

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19922078 ◽

1992 ◽

Vol 57 (10) ◽

pp. 2078-2088 ◽

Cited By ~ 4

Author(s):

Mohinder S. Chauhan ◽

Kishore C. Sharma ◽

Sanjay Gupta ◽

Suvarcha Chauhan ◽

Vijay K. Syal

Keyword(s):

Dimethyl Sulfoxide ◽

Binary Mixtures ◽

Molar Conductivity ◽

Viscosity Data ◽

Conductivity Data ◽

Equation Resolution ◽

Solvent Interaction ◽

Sodium Salts ◽

Ionic Components

Molar conductances and viscosities of Bu4NBPh4, NaBPh4 and R4NBr (R ethyl, propyl and butyl) at 35 °C in acetonitrile (AN), dimethylsulfoxide (DMSO) and their binary mixtures have been reported. The conductivity data has been analysed by the Shedlovsky conductance equation and viscosity data by the Jones-Dole equation. Resolution of limiting molar conductivity (Λ0) and viscosity B coefficient of electrolytes into their ionic components have been achieved by the reference salt method. Viscosity A coefficients have been compared with theoretical Aη coefficients. Derived conductance and viscosity parameters have been discussed in terms of the ion-solvent interaction.

Download Full-text