The Influence of Sodium Benzoate on the Alkaline Hydrolysis of Fuchsin: Inhibition Study

2021 ◽  
Vol 46 (1) ◽  
Author(s):  
D. F Latona ◽  
A.E Akinola
Keyword(s):  
Alkaline Hydrolysis ◽  
Sodium Benzoate ◽  
Activation Parameters ◽  
First Order ◽  
First Order Kinetics ◽  
Free Energy Of Activation ◽  
Hydrolytic Reaction ◽  
Presence And Absence ◽  
Gibb’S Free Energy ◽  
Hydrolysis Of

Kinetics of alkaline hydrolysis of Fuchsin in the absence and presence of sodium benzoate was investigated at 546.5 nm by pseudo first order kinetics. The reaction was found to be first order each in [Fuchsin] and [NaOH] in the presence and absence of sodium benzoate. Double reciprocal plot indicates the presence of an intermediate complex in the course of the reaction. Activation parameters were obtained from Erying’s equation as ΔH# 24.70 kJmol-1, ΔS# -0.193 kJK-1mol-1 and ΔG# 82.21 kJ mol-1 in the absence of sodium benzoate and ΔH# 27.59 kJmol-1, ΔS# -0.185 kJ K-1mol-1 and ΔG# 82.72 kJ mol-1in the presence of sodium benzoate. Sodium benzoate plays an inhibitory role in the hydrolysis reaction. The values of the change in Gibb’s free energy of activation shows same mechanism for the hydrolytic reaction in the presence and absence of sodium benzoate. A plausible mechanism is proposed. Keywords: Sodium benzoate, Fuchsin, NaOH, rate law, mechanism

scholarly journals A Fast, Inexpensive, and Safe Method for Residue Analysis of Meptyldinocap in Different Fruits by Liquid Chromatography/Tandem Mass Spectrometry

2010 ◽  
Vol 93 (6) ◽  
pp. 1957-1964 ◽  
Author(s):  
Kaushik Banerjee ◽  
Soma Dasgupta ◽  
Manjusha R Jadhav ◽  
Dattatraya G Naik ◽  
Axel Patrick Ligon ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Residue Analysis ◽  
First Order ◽  
First Order Kinetics ◽  
Free Energy Of Activation ◽  
Subsequent Hydrolysis ◽  
Liquid Chromatography Tandem Mass ◽  
Rate Kinetics ◽  
Entropy Of Activation ◽  
Hydrolysis Of

Abstract An analytical method is reported for residue analysis of the fungicide meptyldinocap in different fruit matrixes that involves extraction with ethyl acetate, hydrolysis of the residues with ethanolamine, and determination by LC/MS/MS. The method involves extraction of 10 g sample with 10 mL ethyl acetate; evaporation of the ethyl acetate phase to dryness, and subsequent hydrolysis of the residues to 4,6-dinitro-2-(1-methylheptyl) phenol on reaction with 1 ethanolamine. The pH of this hydrolyzed product was neutralized with formic acid and analyzed by LC/MS/MS. The hydrolysis reaction followed pseudo-first-order kinetics, and the reaction product was spectroscopically confirmed as 2-(1-methylheptyl)-4,6-dinitrophenol. The method offered >80 recoveries at an LOQ of 10 ng/g for grape and mango, 25 ng/g for pomegranate with intralaboratory Horwitz ratio <0.5, and measurement uncertainties <10 at LOQ levels. Considering first-order rate kinetics, activation energy, enthalpy of activation, and entropy of activation varied as solvent > mango > grape > pomegranate. Free energy of activation at 298 K was higher than at 280 K and was similar for solvent and three matrixes at both temperatures.

scholarly journals MW irradiation and ionic liquids as green tools in hydrolyses and alcoholyses

2020 ◽  
Vol 10 (1) ◽  
pp. 001-010 ◽  
Author(s):  
Nikoletta Harsági ◽  
Betti Szőllősi ◽  
Nóra Zsuzsa Kiss ◽  
György Keglevich
Keyword(s):  
Ionic Liquids ◽  
Alkaline Hydrolysis ◽  
Alkyl Group ◽  
Phosphinic Acid ◽  
Reaction Times ◽  
Alternative Possibility ◽  
First Order ◽  
Pseudo First Order ◽  
Mw Irradiation ◽  
Hydrolysis Of

Abstract The optimized HCl-catalyzed hydrolysis of alkyl diphenylphosphinates is described. The reaction times and pseudo-first-order rate constants suggested the iPr > Me > Et ∼ Pr ∼ Bu order of reactivity in respect of the alkyl group of the phosphinates. The MW-assisted p-toluenesulfonic acid (PTSA)-catalyzed variation means a better alternative possibility due to the shorter reaction times, and the alkaline hydrolysis is another option. The transesterification of alkyl diphenylphosphinates took place only in the presence of suitable ionic liquids, such as butyl-methylimidazolium hexafluorophosphorate ([bmim][PF6]) and butyl-methylimidazolium tetrafluoroborate ([bmim][BF4]). The application of ethyl-methylimidazolium hydrosulfate ([emim][HSO4]) and butyl-methylimidazolium chloride ([bmim][Cl]) was not too efficient, as the formation of the ester was accompanied by the fission of the O–C bond resulting in the formation of Ph2P(O)OH. This surprising transformation may be utilized in the phosphinate → phosphinic acid conversion.

Time course and vectorial nature of albumin metabolism in isolated perfused rabbit PCT

1988 ◽  
Vol 255 (3) ◽  
pp. F520-F528 ◽  
Author(s):  
C. H. Park
Keyword(s):  
Time Course ◽  
Hydrolysis Product ◽  
High Capacity ◽  
Intact Protein ◽  
Renal Metabolism ◽  
First Order ◽  
First Order Kinetics ◽  
Hydrolysis Products ◽  
Renal Tubular ◽  
Hydrolysis Of

The time course and vectorial nature of renal metabolism of albumin (Alb) were studied. The tubular absorption, accumulation, and hydrolysis of Alb and the release of the hydrolysis products were determined in the isolated rabbit proximal convoluted tubule (PCT) perfused with tritiated Alb ([3H3C]Alb) at 36.4 micrograms/ml. The Alb absorption across the apical membrane was constant (99.9 +/- 4.9 x 10(-3) ng.min-1.mm-1). In contrast, the accumulation and hydrolysis of Alb in the cells increased nonlinearly with time. The bulk of the tritium that accumulated in the cells was associated with intact [3H3C]Alb. Only the final hydrolysis products were released from the cells and these first appeared in the peritubular bath 6–7 min after the start of perfusion of the tubule with [3H3C]Alb. The hydrolysis product was not detectable in the tubule lumen. The proteolytic activity correlated linearly with the protein load to the cells, characteristic of first-order kinetics and a high-capacity system. The results suggest that the renal tubular handling of proteins proceeds from the apical to the basolateral aspect of the cell. The transcellular processing of Alb is rapid and can occur in 6–7 min. The accumulation of intact protein in the cell and the first-order kinetics of hydrolysis of the absorbed protein suggest that the rate-limiting step in proximal tubular handling of proteins may include the initial hydrolysis of protein or reside in steps that precede the hydrolysis.

scholarly journals Kinetic Profiling of the Hydrolytic Reaction of Benazepril: Metabolic Pathway Simulation

2018 ◽  
Vol 101 (4) ◽  
pp. 1009-1013
Author(s):  
A Hemdan ◽  
Adel M Michael
Keyword(s):  
Room Temperature ◽  
Enzyme Inhibitor ◽  
Internal Standard ◽  
Official Method ◽  
First Order ◽  
First Order Kinetics ◽  
Accuracy And Precision ◽  
Inhibitor Analysis ◽  
Hydrolytic Reaction ◽  
Significant Difference

Abstract A simple, specific, and rapid kinetic study of benazepril (BNZ) hydrolysis was developed and validated using HPLC. BNZ was degraded using 0.1 N sodium hydroxide at room temperature to produce benazeprilat, which is an active metabolite of BNZ and acts as an angiotensin-converting enzyme inhibitor. Analysis was carried out using an Athena C18 column (4.6 × 250 mm, 5 µm particle size). The mobile phase consists of a mixture of phosphate buffer (pH 4.5) and acetonitrile (53 + 47, v/v) at a flow rate of 1 mL/min. UV detection was accomplished at 242 nm using moexipril as the internal standard. The method was validated according to International Conference on Harmonization guidelines, and the calibration curve was linear over the range 10–100 µg/mL, with acceptable accuracy and precision. Kinetic profiling of the hydrolysis was shown to follow pseudo-first-order kinetics. The method was applied to the assay of BNZ in combined dosage form with no interference from other ingredients. The obtained results were statistically compared with those of the official method, showing no significant difference.

The kinetics and the mechanism of oxidative decarboxylation of benzilic acid by acidic permanganate (stopped-flow technique) — An autocatalytic study

2004 ◽  
Vol 82 (9) ◽  
pp. 1372-1380 ◽  
Author(s):  
Sairabanu A Farokhi ◽  
Sharanappa T Nandibewoor
Keyword(s):  
Activation Parameters ◽  
Oxidative Decarboxylation ◽  
Two Stage ◽  
First Order ◽  
First Order Kinetics ◽  
Stage Process ◽  
Benzilic Acid ◽  
Reaction Constants ◽  
Kinetics Of ◽  
Good Agreement

The kinetics of the oxidation of benzilic acid by potassium permanganate in an acidic medium were studied spectrophotometrically. The reaction followed a two-stage process, wherein both stages of the reaction followed first-order kinetics with respect to permanganate ion and benzilic acid. The rate of the reaction increased with an increase in acid concentration. Autocatalysis was observed by one of the products, i.e., manganese(II). A composite mechanism involving autocatalysis has been proposed. The activation parameters of the reaction were calculated and discussed and the reaction constants involved in the mechanisms were calculated. There is a good agreement between the observed and calculated rate constants under different experimental conditions.Key words: oxidation, autocatalysis, benzilic acid, two-stage kinetics.

scholarly journals Kinetic Evidence for Near Irreversible Nonionic Micellar Entrapment ofN-(2′-Methoxyphenyl)phthalimide (1) under the Typical Alkaline Reaction Conditions

2014 ◽  
Vol 2014 ◽  
pp. 1-6
Author(s):  
M. Niyaz Khan ◽  
Yoke-Leng Sim ◽  
Azhar Ariffin
Keyword(s):  
Kinetic Analysis ◽  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Total Concentration ◽  
Reaction Conditions ◽  
First Order ◽  
Order Rate ◽  
Alkaline Reaction ◽  
Pseudo First Order ◽  
Hydrolysis Of

The values of pseudo-first-order rate constants (kobs) for alkaline hydrolysis of1, obtained at 1.0 mM NaOH and withinCmEnT(total concentration ofCmEn) range of 3.0–5.0 mM forC12E23and 10–20 mM forC18E20, fail to obey pseudophase micellar (PM) model. The values of the fraction of near irreversibleCmEnmicellar trapped1molecules (FIT1) vary in the range ~0–0.75 forC12E23and ~0–0.83 forC18E20under such conditions. The values ofFIT1become 1.0 at ≥10 mMC12E23and 50 mMC18E20. Kinetic analysis of the observed data at ≥10 mMC12E23shows near irreversible micellar entrapment of1molecules under such conditions.

scholarly journals KINETICS OF REACTION BETWEEN MALACHITE GREEN AND HYDROXYL ION IN THE PRESENCE OF REDUCING SUGARS

2015 ◽  
Vol 23 (23) ◽  
pp. 61-72
Author(s):  
Dayo Felix Latona ◽  
Adewumi Oluwasogo Dada
Keyword(s):  
Malachite Green ◽  
Activation Parameters ◽  
Cell Compartment ◽  
First Order ◽  
Rate Determining Step ◽  
First Order Kinetics ◽  
Hydroxyl Ion ◽  
Kinetics Of Reaction ◽  
Kinetics Of ◽  
Sphere Mechanism

The reaction was studied via pseudo-first-order kinetics using a UV-1800 Shimadzu spectrophotometer with a thermostated cell compartment and interfaced with a computer. The reaction showed first order with respect to malachite green and sugar and hydroxyl ion concentrations. However, the reaction was independent of ionic strength and showed no dependence on the salt effect, indicating an inner sphere mechanism for the reaction. There was no polymerization of the reaction mixture with acrylonitrile, indicating the absence of radicals in the course of the reaction. Michaelis-Menten plot indicated the presence of a reaction intermediate in the rate-determining step. The activation parameters of the reaction have been calculated and products were elucidated by FTIR spectroscopy. The stoichiometry of the reaction is 1:1. A mechanism consistent with the above facts has been suggested.

scholarly journals Phenylcarbamic acid derivatives with integrated n-phenylpiperazine moiety in the structure – kinetics of alkaline hydrolysis study / Deriváty kyseliny fenylkarbámovej s integrovanou n-fenylpiperazínovou zložkou v štruktúre – štúdium kinetiky alkalickej hydrolýzy

2015 ◽  
Vol 62 (2) ◽  
pp. 38-42
Author(s):  
Stankovičová M. ◽  
Miháliková V. ◽  
Mezovský Ľ. ◽  
Lašáková A. ◽  
Medlenová V. ◽  
...  
Keyword(s):  
Alkaline Hydrolysis ◽  
Phenyl Ring ◽  
Arrhenius Equation ◽  
Sodium Hydroxide Solution ◽  
Antimycobacterial Activity ◽  
First Order ◽  
Rate Of Hydrolysis ◽  
Pseudo First Order ◽  
Kinetics Of ◽  
Hydrolysis Of

AbstractIn present work, we have studied kinetics of alkaline hydrolysis of 14 compounds, which are phenylcarbamic acid derivatives with integrated N-phenylpiperazine moiety in the structure. The compounds possessed moderate antiarrhythmic and antimycobacterial activity. Their hydrolysis was carried out in an aqueous medium ethanol sodium hydroxide solution. The course of the hydrolysis was observed spectrophotometrically in visible as well as in ultraviolet regions. The pseudo-first order rate constants were calculated at several temperatures. The values of the activation energy EAwere determined by the Arrhenius equation. The rate of hydrolysis of the compounds under the study increase with the increase in temperature and it has been differentiated according to the substitution of N-phenylpiperazine as well as to the alkoxy substitution on phenyl ring.

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