scholarly journals Studying the kinetics of salicin hydrolysis in an acidic environment

2020 ◽  
Author(s):  
A. B. Sabutova
Keyword(s):  
Aqueous Solutions ◽  
Hplc Method ◽  
Acidic Environment ◽  
Strong Acids ◽  
Kinetics Of ◽  
Hydrolysis Of

The work is devoted to the study of the kinetics of the hydrolysis of salicin in aqueous solutions. To determine salicin in the objects of study, the HPLC method was used. During the study, it was found that the hydrolysis of salicin occurs only in aqueous solutions of strong acids.

Kinetics of the Catalytic Hydrolysis of Concentrated Aqueous Solutions of NaBH4 on Co/TiO2 Powder

2021 ◽  
Vol 62 (3) ◽  
pp. 350-359
Author(s):  
S. I. Shabunya ◽  
V. G. Minkina ◽  
V. I. Kalinin ◽  
N. D. Sankir ◽  
C. T. Altaf
Keyword(s):  
Aqueous Solutions ◽  
Catalytic Hydrolysis ◽  
Tio2 Powder ◽  
Concentrated Aqueous Solutions ◽  
Kinetics Of ◽  
Hydrolysis Of

Kinetics of hydrolysis of bromine in aqueous solutions of chloride and bromide ions

1977 ◽  
Vol 26 (8) ◽  
pp. 1571-1575
Author(s):  
A. G. Ivanchenko ◽  
M. N. Vargaftik ◽  
L. A. Katsman ◽  
V. I. Ksenzenko ◽  
S. M. Gutiontov
Keyword(s):  
Aqueous Solutions ◽  
Kinetics Of Hydrolysis ◽  
Bromide Ions ◽  
Kinetics Of ◽  
Hydrolysis Of

A study of ofloxacin and levofloxacin photostability in aqueous solutions

10.20883/178 ◽  
2016 ◽  
Vol 85 (4) ◽  
pp. 238
Author(s):  
Anita Frąckowiak ◽  
Bartosz Kamiński ◽  
Bartosz Urbaniak ◽  
Paweł Dereziński ◽  
Agnieszka Klupczyńska ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
High Performance ◽  
Degradation Products ◽  
Mercury Vapor ◽  
Degradation Process ◽  
Hplc Method ◽  
Photodegradation Products ◽  
Kinetics Of Degradation ◽  
High Performance Capillary Electrophoresis ◽  
Kinetics Of

Introduction. The photostability is one of the most important properties of drugs. A comprehensive study of ofloxacin (OFX) and levofloxacin (LVX) photostability in aqueous solutions was performed. Ofloxacin is a chemotherapeutic agent belonging to the second generation fluoroquinolones and is a racemate of (R)-(+)-ofloxacin and (S)-(-)-ofloxacin (LVX).Material and Methods. Samples of OFX and LVX were subjected to stress conditions of UV irradiation using a mercury‑vapor lamp. The study involved development of enantioselective high‑performance liquid chromatography (HPLC) and high‑performance capillary electrophoresis (HPCE) methods for separation of OFX enantiomers and their degradation products. These methods were used to monitor the degradation process of OFX and LVX under irradiation and to determine the kinetics of degradation of these antibacterial agents. Moreover, the identification of photoproducts was also attempted. The structure of the main photoproducts was examined by mass spectrometry (MS).Results and Conclusions. Using HPLC method it was possible to observe two products of OFX degradation and only one for LVX, while using HPCE method eight products of OFX degradation and six of LVX were observed. Some of the photoproducts retain character of optically active compounds. The trend of the photodegradation of both tested compounds was described by autocatalytic reaction proceeding according to the Prout‑Tompkins model. Some of the products of the decomposition catalyze this reaction. The rate of degradation was similar for both enantiomers but t0.5 was slightly longer for LVX than OFX. Based on MS experiments the photodegradation products of the studied fluoroquinolones and possible pathways of UV induced decay were identified.

The Kinetics of the α-Chymotrypsin Catalyzed Hydrolysis of Nicotinyl-L-tyrosinamide in Aqueous Solutions at 25° and pH 7.91

1951 ◽  
Vol 73 (7) ◽  
pp. 3231-3234 ◽  
Author(s):  
H. T. Huang ◽  
R. V. MacAllister ◽  
D. W. Thomas ◽  
Carl Niemann
Keyword(s):  
Aqueous Solutions ◽  
Kinetics Of ◽  
Hydrolysis Of

scholarly journals The Influence of pH and Temperature on the Stability ofN-[(Piperidine)methylene]daunorubicin Hydrochloride and a Comparison of the Stability of Daunorubicin and Its Four New Amidine Derivatives in Aqueous Solutions

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Mikołaj Piekarski ◽  
Agnieszka Dołhań ◽  
Judyta Cielecka-Piontek ◽  
Przemysław Zalewski ◽  
Witold Kycler ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Hplc Method ◽  
Base Catalysis ◽  
Spontaneous Hydrolysis ◽  
Influence Of Water ◽  
Enthalpy And Entropy ◽  
The Stability ◽  
Protonated Molecules ◽  
Influence Of Ph ◽  
Hydrolysis Of

The influence of pH and temperature on the stability ofN-[(piperidine)methylene]daunorubicin hydrochloride (PPD) was investigated. Degradation was studied using an HPLC method. Specific acid-base catalysis of PPD involves hydrolysis of protonated molecules of PPD catalyzed by hydrogen ions and spontaneous hydrolysis under the influence of water zwitterions, unprotonated molecules, and monoanions of PPD. The thermodynamic parameters of these reactions, energy, enthalpy, and entropy, were calculated. Also, the stability of daunorubicin and its new amidine derivatives (piperidine, morpholine, pyrrolidine, and hexahydroazepin-1-yl) in aqueous solutions was compared and discussed.

Sign in / Sign up

Export Citation Format

Share Document