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Papers by Masood Qureshi
Data Revues 16310748 V15i6 S1631074812000604, Jun 19, 2012
Journal of Photochemistry and Photobiology B: Biology, 2013
The binding of antihypertensive acetazolamide with eleven nonsteroidal anti-inflammatory drugs (N... more The binding of antihypertensive acetazolamide with eleven nonsteroidal anti-inflammatory drugs (NSA-IDs) was investigated at pH 3, 7 and 9.5 with the objective of monitoring their interactive pharmacokinetics during digestion and absorption in human body. The results of UV-Vis spectroscopy and cyclic voltammetry revealed two NSAIDs (acetaminophen and dichlofenic sodium) to interact with acetazolamide in stomach fluid conditions forming complexes of 1:1 and 1:2 stoichiometry. The complexation ratio was also verified by computational methods. The strong binding propensity of acetaminophen and dichlofenic sodium with acetazolamide prohibited their combined therapy. However, the poor binding affinity of aspirin and mefinamic acid suggested these drugs as preferred NSAIDs to be prescribed with acetazolamide.
Experimental and theoretical investigations were carried out on 2 sets of chalcones. Set 1 has an... more Experimental and theoretical investigations were carried out on 2 sets of chalcones. Set 1 has an OH group on ring A and Set 2 does not, and both have different substituents on ring B at different positions. The experimental investigations comprised cyclic voltammetric (CV) studies to determine the reactivity in terms of redox potentials in DMF at room temperature (23 ± 1 • C). Electrochemical parameters from cyclic voltammograms were used to evaluate the reversibility of electron transfer, standard reduction potentials, solvation energies, electron affinities, diffusion coefficients, critical scan rates and heterogeneous electron transfer rate constants. Heterogeneous electron transfer rate constants were determined experimentally by Gileadi's method for the Set 2 chalcones only. Computational studies included the use of MO theory with semi-empirical AM1 and PM3 approximations for the determination of optimized geometries and the energies of lowest unoccupied molecular orbital (ELUMO). An attempt was also made to correlate the experimental and theoretical parameters.
Journal of The Electrochemical Society, 2014
The electrochemical response of two biologically important phenazine derivatives was examined by ... more The electrochemical response of two biologically important phenazine derivatives was examined by using cyclic, differential pulse and square wave voltammetry in a wide pH range of 2.0-12.0. Cyclic voltammetry was employed for the determination of heterogeneous electron transfer rate constant and diffusion coefficient of the analytes. The value of electron transfer rate constant was used for evaluation of Gibbs free energy, enthalpy and entropy changes of redox reactions of the compounds. Differential pulse voltammetry was used for the determination of number of protons and electrons involved in the redox processes. Limits of detection and quantification were assessed by square wave voltammetry. The detailed pH dependent redox mechanisms of the compounds were proposed on the basis of experimental results which were further supported by theoretical calculations. These redox mechanistic pathways are expected to play a key role in understanding the necessary aspects of structure-activity relationships and exploring the hidden routes by which this class of compounds exert its biochemical actions.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008
In the present study CT complexes of 2-, 3- and 4-Picolines with (DDQ) 2, 3-dichloro-5, 6-dicyano... more In the present study CT complexes of 2-, 3- and 4-Picolines with (DDQ) 2, 3-dichloro-5, 6-dicyano parabenzoquinone (pi-acceptor) and (I2) Iodine (sigma-acceptor) have been investigated spectrophotometrically in three different solvents (CCl4, CHCl3 and CH2Cl2) at six different temperatures. The formation constants of the CT complexes were determined by the Benesi-Hildebrand equation. The thermodynamic parameters were calculated by Van(')t Hoff equation. The DeltaH degrees , DeltaG degrees and DeltaS degrees values are all negative implying that the formation of studied complexes is exothermic in nature.
Data Revues 16310748 V15i6 S1631074812000604, Jun 19, 2012
Journal of Photochemistry and Photobiology B: Biology, 2013
The binding of antihypertensive acetazolamide with eleven nonsteroidal anti-inflammatory drugs (N... more The binding of antihypertensive acetazolamide with eleven nonsteroidal anti-inflammatory drugs (NSA-IDs) was investigated at pH 3, 7 and 9.5 with the objective of monitoring their interactive pharmacokinetics during digestion and absorption in human body. The results of UV-Vis spectroscopy and cyclic voltammetry revealed two NSAIDs (acetaminophen and dichlofenic sodium) to interact with acetazolamide in stomach fluid conditions forming complexes of 1:1 and 1:2 stoichiometry. The complexation ratio was also verified by computational methods. The strong binding propensity of acetaminophen and dichlofenic sodium with acetazolamide prohibited their combined therapy. However, the poor binding affinity of aspirin and mefinamic acid suggested these drugs as preferred NSAIDs to be prescribed with acetazolamide.
Experimental and theoretical investigations were carried out on 2 sets of chalcones. Set 1 has an... more Experimental and theoretical investigations were carried out on 2 sets of chalcones. Set 1 has an OH group on ring A and Set 2 does not, and both have different substituents on ring B at different positions. The experimental investigations comprised cyclic voltammetric (CV) studies to determine the reactivity in terms of redox potentials in DMF at room temperature (23 ± 1 • C). Electrochemical parameters from cyclic voltammograms were used to evaluate the reversibility of electron transfer, standard reduction potentials, solvation energies, electron affinities, diffusion coefficients, critical scan rates and heterogeneous electron transfer rate constants. Heterogeneous electron transfer rate constants were determined experimentally by Gileadi's method for the Set 2 chalcones only. Computational studies included the use of MO theory with semi-empirical AM1 and PM3 approximations for the determination of optimized geometries and the energies of lowest unoccupied molecular orbital (ELUMO). An attempt was also made to correlate the experimental and theoretical parameters.
Journal of The Electrochemical Society, 2014
The electrochemical response of two biologically important phenazine derivatives was examined by ... more The electrochemical response of two biologically important phenazine derivatives was examined by using cyclic, differential pulse and square wave voltammetry in a wide pH range of 2.0-12.0. Cyclic voltammetry was employed for the determination of heterogeneous electron transfer rate constant and diffusion coefficient of the analytes. The value of electron transfer rate constant was used for evaluation of Gibbs free energy, enthalpy and entropy changes of redox reactions of the compounds. Differential pulse voltammetry was used for the determination of number of protons and electrons involved in the redox processes. Limits of detection and quantification were assessed by square wave voltammetry. The detailed pH dependent redox mechanisms of the compounds were proposed on the basis of experimental results which were further supported by theoretical calculations. These redox mechanistic pathways are expected to play a key role in understanding the necessary aspects of structure-activity relationships and exploring the hidden routes by which this class of compounds exert its biochemical actions.
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008
In the present study CT complexes of 2-, 3- and 4-Picolines with (DDQ) 2, 3-dichloro-5, 6-dicyano... more In the present study CT complexes of 2-, 3- and 4-Picolines with (DDQ) 2, 3-dichloro-5, 6-dicyano parabenzoquinone (pi-acceptor) and (I2) Iodine (sigma-acceptor) have been investigated spectrophotometrically in three different solvents (CCl4, CHCl3 and CH2Cl2) at six different temperatures. The formation constants of the CT complexes were determined by the Benesi-Hildebrand equation. The thermodynamic parameters were calculated by Van(')t Hoff equation. The DeltaH degrees , DeltaG degrees and DeltaS degrees values are all negative implying that the formation of studied complexes is exothermic in nature.