scholarly journals Oxidation of Cinacalcet Hydrochloride by Chloramine-B in Acid Medium: A Kinetic and Mechanistic Study

2021 ◽  
Vol 33 (9) ◽  
pp. 2065-2068
Author(s):  
Nichhapurada Kallesha ◽  
Ningegowda Prasad ◽  
N. Shivakumara ◽  
Kereyagalahally H. Narasimhamurthy
Keyword(s):  
Thermodynamic Parameters ◽  
Acid Medium ◽  
Oxidation Product ◽  
Mechanistic Study ◽  
Spectroscopic Methods ◽  
Arrhenius Plots ◽  
Rate Law ◽  
Different Temperatures ◽  
Cinacalcet Hydrochloride ◽  
Hcl Medium

Kinetic and mechanistic study of cinacalcet hydrochloride by chloramine-B (CAB) in HCl medium at 308 K was the aim of this work. Analyzed the reaction at five different temperatures and determined the thermodynamic parameters using Arrhenius plots. The reaction had a stoichiometry of 1:2 and characterized the oxidation product using chromatographic and spectroscopic methods. The rate law is deduced from the marked effects, which were accompanied by plausible mechanisms.

scholarly journals Kinetic and Mechanism of Uncatalytic Oxidation of Dl-Threonine by Cerium (Iv) in Aqueous Acid Medium

2021 ◽  
pp. 51-63
Author(s):  
Gajanand Sahu ◽  
Sanjay Ghosh
Keyword(s):  
Thermodynamic Parameters ◽  
Acid Medium ◽  
Rate Constant ◽  
Acidic Medium ◽  
Order Reaction ◽  
First Order Reaction ◽  
First Order ◽  
Aqueous Acid ◽  
Rate Of Reaction ◽  
Different Temperatures

Kinetic of uncatalyzed oxidation of DL-Threonine has been studied by Ce (IV) in acidic medium has been investigatigated by spectrophotometer technique.  The rate of reaction determined at three different temperatures ranging from 298 K to 318 K at the interval of 10 K. The reaction has been found to be a first order reaction in presence or in absence of KCl, CTAB, and SDS. The rate constant, decreases with increasing the concentration of [HSO4-] and [H+] ion. The various thermodynamic parameters were calculated at 298 K, 308 K and 318 K. The proposed mechanism and results is discussed.

Oxidation mechanism of carcinogenic bis-azo dyestuff Trypan Blue

1982 ◽  
Vol 47 (10) ◽  
pp. 2746-2748 ◽  
Author(s):  
Miroslav Matrka ◽  
Jana Pípalová
Keyword(s):  
Acid Medium ◽  
Quantitative Evaluation ◽  
Oxidation Product ◽  
Trypan Blue ◽  
Oxidation Mechanism ◽  
Azo Coupling ◽  
Arenediazonium Salt

Oxidation of Trypan Blue with cerium(IV) ion in acid medium gives arenediazonium cation similar to the oxidation product of N,N-dimethyl-4-aminoazobenzene. Quantitative evaluation of the arenediazonium salt formed has been carried out spectrophotometrically after previous C-azo coupling with 2-naphthol.

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 Thermodynamic studies of substrate binding and spin transitions in human cytochrome P-450 3A4 expressed in yeast microsomes

1996 ◽  
Vol 319 (3) ◽  
pp. 675-681 ◽  
Author(s):  
Jean-Paul RENAUD ◽  
Dmitri R. DAVYDOV ◽  
Karel P. M. HEIRWEGH ◽  
Daniel MANSUY ◽  
Gaston HUI BON HOA
Keyword(s):  
Thermodynamic Parameters ◽  
Protein Interactions ◽  
Substrate Binding ◽  
Principal Component ◽  
Yeast Saccharomyces Cerevisiae ◽  
Human Cytochrome ◽  
Different Temperatures ◽  
Haem Protein ◽  
Cytochrome P 450 ◽  
Spin Transitions

An approach to the quantitative spectral analysis of substrate binding and inactivation of cytochrome P-450 in microsomes is described. The method is based on the application of the principal component analysis technique on the Soret-region spectra measured at different temperatures at various concentrations of substrate. This approach allowed us to study the thermodynamic parameters of substrate binding and spin transitions in human cytochrome P-450 3A4 expressed in yeast (Saccharomyces cerevisiae) microsomes. These parameters are discussed in comparison with the values reported earlier by Ristau et al. [(1979) Acta Biol. Med. Ger. 38, 177–185] for rabbit liver cytochrome P-450 2B4 in solution with benzphetamine as a substrate. Our analysis shows the substrate-free states of 2B4 and 3A4 to be very similar. However, substrate binding seems to perturb haem-protein interactions in 3A4 in contrast with 2B4, where the effect of substrate binding on the thermodynamic parameters of spin transitions was insignificant. The implication of the results for the mechanism of substrate-induced spin shift is discussed.

scholarly journals Perborate Oxidation of Substituted 5-Oxoacids in Aqueous Acetic Acid Medium: A Kinetic and Mechanistic Study

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
S. Shree Devi ◽  
B. Muthukumaran ◽  
P. Krishnamoorthy
Keyword(s):  
Acetic Acid ◽  
Acid Medium ◽  
Reaction Rate ◽  
Reaction Medium ◽  
Activation Parameters ◽  
Reaction Rates ◽  
Mechanistic Study ◽  
Aqueous Acetic Acid ◽  
Sodium Perborate ◽  
Acetic Acid Medium

Kinetics and mechanism of oxidation of substituted 5-oxoacids by sodium perborate in aqueous acetic acid medium have been studied. The reaction exhibits first order both in [perborate] and [5-oxoacid] and second order in [H+]. Variation in ionic strength has no effect on the reaction rate, while the reaction rates are enhanced on lowering the dielectric constant of the reaction medium. Electron releasing substituents in the aromatic ring accelerate the reaction rate and electron withdrawing substituents retard the reaction. The order of reactivity among the studied 5-oxoacids is p-methoxy ≫ p-methyl > p-phenyl > –H > p-chloro > p-bromo > m-nitro. The oxidation is faster than H2O2 oxidation. The formation of H2BO3+ is the reactive species of perborate in the acid medium. Activation parameters have been evaluated using Arrhenius and Eyring’s plots. A mechanism consistent with the observed kinetic data has been proposed and discussed. Based on the mechanism a suitable rate law is derived.

Sign in / Sign up

Export Citation Format

Share Document