scholarly journals Physicochemical studies of binding of 4-methylumbelliferyl β-d-galactopyranoside to cold agglutinin

1989 ◽  
Vol 262 (1) ◽  
pp. 357-360 ◽  
Author(s):  
D Mitra ◽  
M Sarkar
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Binding Sites ◽  
Association Constants ◽  
Cold Agglutinin ◽  
Physicochemical Studies ◽  
Different Temperatures ◽  
Number Of Binding Sites ◽  
Enthalpy And Entropy ◽  
Quenching Phenomenon

The fluorescence of 4-methylumbelliferyl beta-D-galactopyranoside (MeUmbGalp) was quenched in the presence of cold agglutinin, showing that there was binding between MeUmbGalp and cold agglutinin. That binding was saccharide-specific. By using this quenching phenomenon, the association constants (Ka) of the binding of cold agglutinin at different temperatures (10 degrees C and 15 degrees C) to MeUmbGalp and also the number of binding sites were calculated. The Ka values were found to be 2.63 x 10(3) M-1 at 10 degrees C and 1.58 x 10(3) M-1 at 15 degrees C. Though there is a change in Ka values, the number of binding sites was calculated to be six at both temperatures (10 degrees C and 15 degrees C). From the Ka values the thermodynamic parameters (free energy, enthalpy and entropy) of the binding were derived, and analysis of the data indicated that the binding is spontaneous, exothermic and hydrophobic in nature.

scholarly journals AVALIAÇÃO DOS PARÂMETROS TERMODINÂMICOS E CINÉTICOS DE CENOURAS SUBMETIDAS A SECAGEM CONVECTIVA

e-xacta ◽  
2017 ◽  
Vol 10 (2) ◽  
pp. 73 ◽  
Author(s):  
Heloísa Righi Pessoa da Silva ◽  
Roberta Pazinato Cuco ◽  
Barbara Daniele Almeida Porciuncula ◽  
Camila Da Silva
Keyword(s):  
Experimental Data ◽  
Free Energy ◽  
Mathematical Models ◽  
Thermodynamic Parameters ◽  
Kinetic Data ◽  
Temperature Characteristic ◽  
Different Temperatures ◽  
Endothermic Process ◽  
Degree Of Order

<p>Este estudo tem como objetivo a obtenção de dados cinéticos da secagem de cenouras, bem como o ajuste de modelos matemáticos aos dados experimentais e determinação dos parâmetros termodinâmicos do processo. Buscando este propósito, experimentos foram conduzidos em estufa com renovação e circulação de ar, nas temperaturas de 50, 60, 70 e 80 °C. Os modelos matemáticos foram ajustados aos dados das cinéticas de secagem à diferentes temperaturas, e os modelos de Page e de Midilli apresentaram o maior coeficiente de correlação (R<sup>2</sup>) e menor valor de RMSE. Da análise termodinâmica verificou-se que a entalpia e a energia livre de Gibbs diminuíram com o aumento da temperatura, característico de um processo endotérmico. A entropia apresentou valores negativos e diminuiu com a diminuição na temperatura de secagem, isto indica que há um aumento no grau de ordem do sistema, considerado desfavorável entropicamente.</p><p> </p><p>ABSTRACT</p><p>This study aims to obtain kinetic data of carrot drying, as well as the adjustment of mathematical models to the experimental data and determination of the thermodynamic parameters of the process. For this purpose, experiments were conducted in an oven with renovation and circulation of air, at temperatures of 50, 60, 70 and 80 °C. The mathematical models were adjusted to the drying kinetics data at different temperatures, and the Page and de Midilli models presented the highest correlation coefficient (R<sup>2</sup>) and lowest RMSE values. From the thermodynamic analysis it was verified that the enthalpy and the free energy of Gibbs decreased with the increase of the temperature, characteristic of an endothermic process. The entropy presented negative values and decreased with the decrease in the drying temperature, this indicates that there is an increase in the degree of order of the system, considered as entropically unfavorable.</p>

scholarly journals Sewage Water Deironing with Carbon Sorbents

2012 ◽  
pp. 90-98
Author(s):  
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Sewage Water ◽  
Dynamic Conditions ◽  
Electroplating Wastewater ◽  
Carbon Sorbents ◽  
Entropy Changes ◽  
Enthalpy And Entropy Changes ◽  
Enthalpy And Entropy

The possibility of extraction of iron cations Fe2+ from the wash plant electroplating wastewater by carbon sorbents IPI-T synthesized in ISTU has been stated in this work. In this paper we studied the regularities of sorption in static and dynamic conditions, the numerical values defined limiting sorption of iron cations Fe2+ in the interval of temperatures 293-313 K. Such thermodynamic parameters of sorption as Gibbs free energy and enthalpy and entropy changes have been calculated.

Study on the Inclusion Interactions of β-Cyclodextrin with Oleic Acid by Competitive Inclusion Method

2011 ◽  
Vol 130-134 ◽  
pp. 847-851 ◽  
Author(s):  
Xue Feng Xu ◽  
Ji Ju Guan ◽  
Rong Jun He
Keyword(s):  
Oleic Acid ◽  
Inclusion Complex ◽  
Thermodynamic Parameters ◽  
Association Constants ◽  
Grinding Wheel ◽  
Stoichiometric Ratio ◽  
Buffer Solution ◽  
Solution Ph ◽  
Inclusion Method ◽  
Different Temperatures

The grinding wheel will have a property of self-lubricating when the inclusion complexes of β-cyclodextrin (β-CD) and oleic acid are used as filler. The association constants and thermodynamic parameters of inclusion complex of β-CD and oleic acid were determined by competitive inclusion method in aqueous buffer solution (pH = 10.50, c = 0.025 mol/L) at different temperatures using phenolphthalein (PP) as a probe. Furthermore, the stoichiometric ratio of the complex was derived by equimolar series method. The results showed that the stoichiometric ratio of the complex was about 1:1 and the thermodynamic parameters of ΔG, ΔH and ΔS were all negative, which indicated that the formation of the inclusion complex was spontaneous, exothermic and enthalpy-driven. Thermogravimetric analysis revealed that the complex began to have a weight loss at 300°C and could withstand the hardening temperature of resin bond grinding wheel.

scholarly journals Influence of Valsartan on the thermodynamics of micellization of anionic surfactant Sodium Dodecyl Sulphate

2016 ◽  
Vol 63 (2) ◽  
pp. 30-36
Author(s):  
L. Stopková ◽  
A. Hriňaková ◽  
Ž. Bezáková ◽  
F. Andriamanty ◽  
V. Žufková
Keyword(s):  
Free Energy ◽  
Gibbs Free Energy ◽  
Anionic Surfactant ◽  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Uv Spectrophotometry ◽  
Micellar Media ◽  
Different Temperatures ◽  
Enthalpy And Entropy

AbstractIn this manuscript was investigated behaviour of drug valsartan by micellar media of anionic surfactant sodium dodecyl sulphate. As the method was used electrical conductivity for the determination of critical micelle concentration at different temperatures (T = 293.15 - 313.15 K), as well as calculated thermodynamic parameters like standard Gibbs free energy, enthalpy and entropy of micellization. According to contribution of Gibbs free energy is the process of micellization primarily controlled by entropy. Solubilization of valsartan was studied in surfactant system at 298.15 K and physiological conditions pH 7.4 using UV-spectrophotometry at different concentration range (0.001 - 0.07 mol/l) of sodium dodecyl sulphate. The solubilization of drug was observed with increasing concentration of surfactant in aqueous solution.

scholarly journals Conductometric Study of Nimesulide in Aqueous Solutions of Hydrotropic Agents at Different Temperatures

2012 ◽  
Vol 9 (1) ◽  
pp. 21-26 ◽  
Author(s):  
Chandravir S. Solanki ◽  
Paresh Mishra ◽  
Mahesh Kumar Talari ◽  
Minaketan Tripathy ◽  
Upendra N. Dash
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Sodium Benzoate ◽  
Sodium Salicylate ◽  
Molar Conductance ◽  
Association Constants ◽  
Sodium Bromide ◽  
Limiting Molar Conductance ◽  
Different Temperatures ◽  
Conductometric Study

Conductance values of nimesulide have been determined in water in 0.1, 0.2, 0.4, 0.6, 0.8, 1 and 2 mol dm-3aqueous solutions of hydrotropic agents (sodium benzoate, sodium salicylate, sodium bromide and nicotinamide) at temperatures 298.15, 303.15, 308.15 and 313.15 K. The conductance values have been used to evaluate the limiting molar conductance and association constants by means of Shedlovsky extrapolation technique. Thermodynamic parameters for the association process of nimesulide in aqueous solutions of hydrotropic agents have also been calculated.

Development of Nano-KIT for Synthesis of Silver and Gold Nanostructures with Emphasis on Biological Applications

2020 ◽  
Vol 12 (8) ◽  
pp. 1018-1027
Author(s):  
Bipin S. Khade ◽  
P. M. Dongre
Keyword(s):  
Binding Sites ◽  
Biological Applications ◽  
X Ray Diffraction ◽  
X Ray ◽  
Research Areas ◽  
Silver Nanostructure ◽  
Transmission Electron ◽  
Number Of Binding Sites ◽  
Cold Condition ◽  
Enthalpy And Entropy

Nano-KIT consist of few standard chemicals (solvents)/constitutes that can be added sequentially by given protocol. Spherical silver (30 nm) and gold (25–30 nm) nanostructure were synthesized instantly in (5–10 min). Surface plasmon resonance for silver 413 nm and gold 545 nm were confirmed synthesis. Synthesized silver has stability more than 36 months in cold condition. Dynamic Light Scattering (DLS), X-ray Diffraction (XRD) and High Resolution-Transmission Electron Microscopy (HR-TEM) revealed 30 nm (silver) and 25–30 nm (gold). Nano-KIT can be used for variety of application in Nano research areas like biomedical and industrial. Synthesized silver nanostructure were analysed with its molecular interaction between Bovine Serum Albumin (BSA). Biocompatibility assays with Red Blood Cells (RBC), number of binding sites, thermodynamic parameters i.e., free energy, enthalpy and entropy were studied.

The Estimation of the Number of Binding Sites for Antibody on Antigen Molecules with Reference to Factor VIII and its Antibody

1976 ◽  
Vol 35 (02) ◽  
pp. 274-288 ◽  
Author(s):  
Judith Pool ◽  
Rosemary Biggs ◽  
R. G Miller
Keyword(s):  
Factor Viii ◽  
Binding Sites ◽  
Theoretical Basis ◽  
Human Antibody ◽  
Rabbit Antibody ◽  
Number Of Binding Sites ◽  
Theoretical Considerations

SummaryThe theoretical basis for determining the number of antibody sites on antigen molecules is examined. The theoretical considerations are applied to factor VIII molecules. Examples based on data available at the Oxford Haemophilia Centre are calculated to illustrate the approach. It is concluded that there are few sites on each factor VIII molecule for human antibody. The three antibodies for which reasonable data were available suggest 1–3 sites for human antibody. The data for rabbit antibody suggest 5–6 sites per factor VIII molecule.

Abnormal Platelet Serotonin Uptake and Binding Sites in Myeloproliferative Disorders

1984 ◽  
Vol 51 (03) ◽  
pp. 349-353 ◽  
Author(s):  
C Caranobe ◽  
P Sié ◽  
F Fernandez ◽  
J Pris ◽  
S Moatti ◽  
...  
Keyword(s):  
Binding Sites ◽  
High Capacity ◽  
Specific Inhibitor ◽  
Myeloproliferative Disorders ◽  
Normal Subjects ◽  
Binding Data ◽  
Full Explanation ◽  
Number Of Binding Sites ◽  
5 Ht Uptake ◽  
Kinetics Of

SummaryA simultaneous investigation of the kinetics of serotonin (5 HT) uptake and of binding sites was carried out in the platelets of normal subjects and of 10 patients affected with various types of myeloproliferative disorders (MD). The 5 HT uptake was analysed according to the Lineweaver-Burk and the Eadie-Hofstee methods. With the two methods, the patient’s platelets exhibited a dramatic reduction of the Vi max and of the Km; in some patients the Eadie-Hofstee analysis revealed that a passive diffusion phenomenon is superimposed on the active 5 HT uptake at least for the higher concentration used. The binding data were analysed with the Scatchard method. Two classes of binding sites (high affinity - low capacity, low affinity - high capacity) were found in normal subjects and patients. Pharmacological studies with imipramine, a specific inhibitor of 5 HT uptake, suggested that both the sites are involved in 5 HT uptake. The number of both binding sites was significantly decreased in patient’s platelets while the affinity constants of these binding sites were not significantly reduced in comparison with those of the control subjects. No correlations were found between Vi max, Km and the number of binding sites. These results suggest that a reduction in the number of platelet membrane acceptors for 5 HT commonly occurs in myeloproliferative disorders but does not provide a full explanation of the uptake defect.

scholarly journals Thermodynamic and detailed kinetic study of the formation of orthophthalaldehyde-agmatine complex by fluorescence intensities

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Khémesse Kital ◽  
Moumouny Traoré ◽  
Diégane Sarr ◽  
Moussa Mbaye ◽  
Mame Diabou Gaye Seye ◽  
...  
Keyword(s):  
Complex Formation ◽  
Thermodynamic Parameters ◽  
Initial Rate ◽  
Reaction Medium ◽  
Standard Entropy ◽  
Step Size ◽  
Formation Reaction ◽  
Different Temperatures ◽  
Kinetics Of ◽  
Complex Formation Process

Abstract The aim of this work is to determine the thermodynamic parameters and the kinetics of complex formation between orthophthalaldehyde (OPA) and agmatine (AGM) in an alkaline medium (pH 13). Firstly, the association constant (Ka) between orthophthalaldehyde and agmatine was determined at different temperatures (between 298 K and 338 K) with a step size of 10 K. Secondly, the thermodynamic parameters such as standard enthalpy (ΔH°), standard entropy (ΔS°),and Gibbs energy (∆G) were calculated, where a positive value of ΔH° (+45.50 kJ/mol) was found, which shows that the reaction is endothermic. In addition, the low value of ΔS°(+0.24 kJ/mol) indicates a slight increase in the disorder in the reaction medium. Furthermore, the negative values of ΔG between −35.62 kJ/mol and −26.02 kJ/mol show that the complex formation process is spontaneous. Finally, the parameters of the kinetics of the reaction between OPA and AGM were determined as follows: when the initial concentration of AGM (5 × 10−6 M) is equal to that of the OPA, the results show that the reaction follows an overall 1.5 order kinetics with an initial rate of 5.1 × 10−7Mmin−1 and a half-life of 8.12 min. The partial order found in relation to the AGM is 0.8. This work shows that the excess of OPA accelerates the formation reaction of the complex.

scholarly journals Kinetics and thermodynamic properties related to the drying of 'Cabacinha' pepper fruits

2016 ◽  
Vol 20 (2) ◽  
pp. 174-180 ◽  
Author(s):  
Hellismar W. da Silva ◽  
Renato S. Rodovalho ◽  
Marya F. Velasco ◽  
Camila F. Silva ◽  
Luís S. R. Vale
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Free Energy ◽  
Thermodynamic Properties ◽  
Gibbs Free Energy ◽  
Removal Rate ◽  
Effective Diffusion ◽  
Drying Time ◽  
Three Samples ◽  
Different Temperatures

ABSTRACT The objective of this study was to determine and model the drying kinetics of 'Cabacinha' pepper fruits at different temperatures of the drying air, as well as obtain the thermodynamic properties involved in the drying process of the product. Drying was carried out under controlled conductions of temperature (60, 70, 80, 90 and 100 °C) using three samples of 130 g of fruit, which were weighed periodically until constant mass. The experimental data were adjusted to different mathematical models often used in the representation of fruit drying. Effective diffusion coefficients, calculated from the mathematical model of liquid diffusion, were used to obtain activation energy, enthalpy, entropy and Gibbs free energy. The Midilli model showed the best fit to the experimental data of drying of 'Cabacinha' pepper fruits. The increase in drying temperature promoted an increase in water removal rate, effective diffusion coefficient and Gibbs free energy, besides a reduction in fruit drying time and in the values of entropy and enthalpy. The activation energy for the drying of pepper fruits was 36.09 kJ mol-1.

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