Vijay Devra
@dce.rajasthan.gov.in
Professor
J.D.B. Govt. Girls College Kota Rajasthan
EDUCATION
M.Sc ,Ph.D
RESEARCH, TEACHING, or OTHER INTERESTS
Biochemistry, Chemistry, Materials Chemistry, Spectroscopy
Scopus Publications
Scopus Publications
Vijay Devra
Elsevier
Hussien AboDalam, Vijay Devra, Farah K. Ahmed, Bin Li, and Kamel A. Abd-Elsalam
Elsevier
Vijay Devra
Elsevier
Gajala Tazwar and Vijay Devra
Bulletin of Chemical Reaction Engineering and Catalysis
Soluble colloidal manganese dioxide was formed by reduction of potassium permanganate with sodium thiosulphate in neutral aqueous medium at 25 ºC. The obtained nano-sized colloidal manganese dioxide was found to be dark reddish-brown in color and stable for several months. The formation of manganese dioxide was confirmed by UV-visible spectrophotometer and determination of oxidation state of Mn species in manganese dioxide. The effect of different concentration of sodium thiosulphate on the formation of manganese dioxide was also studied. The nano-sized colloid manganese dioxide was characterized by transmission electron microscopy and Fourier transform infrared spectrophotometer. The formed soluble colloidal manganese dioxide was used as an oxidant in oxidation of ciprofloxacin in perchloric acid medium at 35 ºC. The reaction was first-order concerning to concentration of manganese dioxide and hydrogen ion but fractional order with ciprofloxacin. The results suggest formation of complex between ciprofloxacin and manganese dioxide. The oxidation products were also identified based on stoichiometric and characterization results. Copyright © 2020 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).
Niharika Nagar and Vijay Devra
Springer Science and Business Media LLC
Gajala Tazwar and Vijay Devra
Springer Science and Business Media LLC
Niharika Nagar and Vijay Devra
Elsevier BV
Niharika Nagar and Vijay Devra
Elsevier BV
Niharika Nagar and Vijay Devra
Elsevier BV
Niharika Nagar and Vijay Devra
Elsevier BV
Shikha Jain, Ankita Jain, and Vijay Devra
Elsevier BV
Gajala Tazwar, Ankita Jain, and Vijay Devra
Springer Science and Business Media LLC
Gajala Tazwar, Ankita Jain, Naveen Mittal, and Vijay Devra
Wiley
The kinetic and mechanistic investigation of oxidation of levofloxacin (LF) has been studied by permanganate ion in aqueous sulphuric acid medium at 25°C. The reaction followed first-order kinetics with respect to [LF], and [H+] in their lower concentrations range, tending to zero-order at their higher concentrations. The effect of added products and dielectric constant of the medium was studied on the rate of reaction. Effect of varying salt electrolyte concentration was insignificant showing that the molecular species was involved in the rate determining step. The main products were identified by spot test, FT-IR, and LC-MS. A mechanism was proposed on the basis of experimental results. The activation parameters with respect to the slow step of the mechanism were evaluated, and the thermodynamic parameters were also determined and discussed.Potassium permanganate widely used as oxidizing agent in the kinetics of number of organic and biological active compounds. Permanganate is multi-electronoxidant, which can exist in various oxidation states, among which +7 is its highest oxidation state. In acidic medium it exists in different forms as HMnO4, HMnO4+, HMnO3, Mn2O7 and one depending on the nature of the reductant. Levofloxacin is a broad spectrum drug of activity against various bacteria, including gram-positive and gram-negative microorganisms. Kinetic measurements were performed on a Peltier accessory (temperature-Controlled) attached to a U.V.3000+ UV-Visible spectrophotometer (LABINDIA).The product analysis is characterized by LC-ESI-MS and FT-IR studies. The reaction stoichiometry indicates that 5 moles of levofloxacin require 2 moles of Mn(VII). The oxidation products were identified as 7amino fluoroquinolone and Mn (II). The reaction shows first order kinetics with respect to MnO4and fractional order with respect to levofloxacin and hydrogen ion concentration. The effect of added product, varying salt electrolyte were studied on the rate of reaction. The rate constant of the slowest step and other equilibrium constants involved in the mechanism are evaluated. Overall mechanistic sequence described here is consistent with product, mechanistic and kinetic studies.
Ankita Jain, Gajala Tazwar, and Vijay Devra
Journal of Applied Pharmaceutical Science
ABSTRACT
The kinetics and mechanism of oxidation of nalidixic acid (NA) by permanganate ion in alkaline medium have been studied at 40 ± 1oC. The Stoichiometry was observed to be 2:1 in terms of mole ratio of permanganate ion and nalidixic acid consumed. The reaction shows first order with respect to oxidant and fractional order in both the substrate and alkali concentration. The oxidation reaction proceeds via an alkali permanganate species that forms a complex with nalidixic acid and the complex then decomposes to give the product. The effects of added products and ionic strength have also been investigated. The main products identified were hydroxylated NA and Mn(VI). A mechanism was proposed on the basis of experimental results. Investigation of the reaction at different temperature allowed the determination of the activation parameters with respect to the slow step of the proposed mechanism.
Niharika Nagar, Shikha Jain, Pranav Kachhawah, and Vijay Devra
Springer Science and Business Media LLC
Shikha JAIN, Ankita JAIN, Pranav KACHHAWAH, and Vijay DEVRA
Elsevier BV
Khushboo Srivastava, Vijay Devra, and Ashu Rani
Elsevier BV