Anodically generated manganese(III) acetate for the oxidation of ? ? amino acids in aqueous acetic acid: A kinetic study

Amino Acids ◽  
1995 ◽  
Vol 8 (3) ◽  
pp. 291-303 ◽  
Author(s):  
B. S. Sherigara ◽  
K. I. Bhat ◽  
I. Pinto
2004 ◽  
Vol 1 (2) ◽  
pp. 127-131 ◽  
Author(s):  
N. A. Mohamed Farook ◽  
R. Prabaharan ◽  
S. Rahini ◽  
R. Senthil Kumar ◽  
G. Rajamahendran ◽  
...  

The kinetics of oxidation of some amino acids namely, glycine, alanine, aspartic acid, arginine, and histidine, (AA) byN-chlorosaccharin (NCSA) in aqueous acetic acid medium in the presence of perchloric acid have been investigated. The observed rate of oxidation is first order in [AA], [NCSA] and of inverse fractional order in [H+]. The main product of the oxidation is the corresponding aldehyde. The ionic strength on the reaction rate has no significant effect. The effect of changing the dielectric constant of the medium on the rate indicates the reaction to be of dipole-dipole type. Hypochlorous acid has been postulated as the reactive oxidizing species. The reaction constants involved in the mechanism are derived. The activation parameters are computed with respect to slow step of the mechanism.


Author(s):  
S. Parimala Vaijayanthi ◽  
N. Mathiyalagan

The kinetics of oxidation of amino acids namely, alanine, glycine, leucine, phenyl alanine and valine by N-chloropyrazinamide (NCPZA) in aqueous acetic acid medium in the presence of hydrochloric acid have been investigated. The observed rate of oxidation is first order in [NCPZA], [H+] and [Clˉ]. The order with respect to [amino acid] is zero. The rate of oxidation increases with increase in the percentage of acetic acid. The reaction rate increases slightly with increase in ionic strength, while retards with addition of pyrazinamide. Arrhenius and thermodynamic activation parameters have been evaluated from Arrhenius plot by studying the reaction at different temperatures. A most probable reaction mechanism has been proposed and an appropriate rate law is deduced toaccount for the observed kinetic data.


2004 ◽  
Vol 1 (2) ◽  
pp. 132-136 ◽  
Author(s):  
N. A. Mohamed Farook ◽  
G. A. Seyed Dameem ◽  
A. Murugesan ◽  
M. Kanagaraj

The kinetics of oxidation of some essential amino acids namely, valine, leucine and phenylalanine, (AA) byN-chlorosaccharin (NCSA) in aqueous acetic acid medium in the presence of perchloric acid have been investigated. The observed rate of oxidation is first order in [AA], [NCSA] and of inverse fractional order in [H+]. The main product of the oxidation is the corresponding aldehyde. The ionic strength on the reaction rate has no significant effect. The effect of changing the dielectric constant of the medium on the rate indicates the reaction to be of dipole-dipole type. Hypochlorous acid has been postulated as the reactive oxidizing species. The reaction constants involved in the mechanism are derived. The activation parameters are computed with respect to slow step of the mechanism


1976 ◽  
Vol 29 (7) ◽  
pp. 1449 ◽  
Author(s):  
V Balasubramanian ◽  
V Thiagarajan

The chlorination of acetone in aqueous acidic medium in the presence of acetic acid and dimethylformamide was subjected to kinetic study. Although the kinetics follows the traditional mechanism at high concentrations of chloramine-T (cat) and in aqueous acetic acid in the presence of sodium acetate, a term in the rate law independent of ketone concentration is reported for the first time in strongly acidic medium at low concentrations of chloramine-T. Generation of the chlorinating species is considered as the rate-determining step (Scheme 1). The mechanistic changes which occur on addition of chloride and on changing the structure of the ketone are reported. The effect of acetate on the rate in aqueous acetic acid medium is rationalized by invoking a prior equilibrium formation of enolate followed by a rate-controlling chlorination by chlorinium acetate. The retardation in rate and the consequent changes in mechanism in the case of p-bromo- and p-nitroacetophenone are accounted for by invoking a complex between the enol and the positive chlorine species similar to that in the mechanism for the chlorination of phenols.


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