Afzal Shah - Academia.edu (original) (raw)
Papers by Afzal Shah
European journal of medicinal chemistry, Oct 1, 2009
Three new triorganotin(IV) dithiocarboxylates (1–3) with general formula R3SnL, where R=C4H9 (1),... more Three new triorganotin(IV) dithiocarboxylates (1–3) with general formula R3SnL, where R=C4H9 (1), C6H11 (2), C6H5 (3) and L=4-(4-nitrophenyl)piperazine-1-carbodithioate, have been synthesized and characterized by elemental analysis, Raman, FT-IR, multinuclear NMR (1H, 13C and 119Sn) and mass spectrometry. The crystal structure of complex 3 confirmed distorted trigonal-bipyramidal geometry around Sn atom. The interaction of compounds 1–3 with DNA was investigated by
RSC Advances, 2022
Nanoparticles bind to the surface of the cell membranes of microbes altering their basic cell fun... more Nanoparticles bind to the surface of the cell membranes of microbes altering their basic cell functions and resulting in cell death.
Global Challenges, 2018
Electrochemical capacitors (ECs) are a vital class of electrical energy storage (EES) devices tha... more Electrochemical capacitors (ECs) are a vital class of electrical energy storage (EES) devices that display the capacity of rapid charging and provide high power density. In the current era, interest in using ionic liquids (ILs) in high‐performance EES devices has grown exponentially, as this novel versatile electrolyte media is associated with high thermal stability, excellent ionic conductivity, and the capability to withstand high voltages without undergoing decomposition. ILs are therefore potentially useful materials for improving the energy/power performances of ECs without compromising on safety, cyclic stability, and power density. The current review article underscores the importance of ILs as sustainable and high‐performance electrolytes for electrochemical capacitors.
Bioelectrochemistry, 2018
... Fouzia Perveen, Rumana Qureshi*, Afzal Shah, Safeer Ahmed, Farzana Latif Ansari, Saima Kalsoo... more ... Fouzia Perveen, Rumana Qureshi*, Afzal Shah, Safeer Ahmed, Farzana Latif Ansari, Saima Kalsoom and Sumera Mehboob ... Amtul, Z., Follmer, C., Mahboob, S., Rahman, AU, Mazhar, M.,Khan, KM, Siddiqui, RA, Muhammad, S., Kazmi, SA, and Choudhary, MI (2007) Germa-c ...
International journal of pharmaceutics, Jan 7, 2018
Various types of nanoparticles (NPs) have been used in delivering anticancer drugs to the site of... more Various types of nanoparticles (NPs) have been used in delivering anticancer drugs to the site of action. This area has become more attractive in recent years due to optimal size and negligible undesirable side effects caused by the NPs. The focus of this review is to explore various types of NPs and their surface/chemical modifications as well as attachment of targeting ligands for tuning their properties in order to facilitate targeted delivery to the cancer sites in a rate-controlled manner. Heme compatibility, biodistribution, longer circulation time, hydrophilic lipophilic balance for high bioavailability, prevention of drug degradation and leakage are important in transporting drugs to the targeted cancer sites. The review discusses advantages of polymeric, magnetic, gold, and mesoporous silica NPs in delivering chemotherapeutic agents over the conventional dosage formulations along with their shortcomings/risks and possible solutions/alternatives.
Electrochimica Acta, 2016
A highly sensitive electrochemical sensor based on immobilization of a newly synthesized urea fun... more A highly sensitive electrochemical sensor based on immobilization of a newly synthesized urea functionality containing surfactant, 1-(2, 4-dinitrophenyl)-dodecanoylthiourea (DAN), possessing soil fertility enhancing characteristics, was developed for the detection of Hg(II) using cyclic, square wave and differential pulse voltammetry. Under suitable experimental conditions, calibration plot with a good linearity up to 2 µg/L was obtained with a detection limit of 0.64 µg/L and sensitivity of 0.164 µAL/µg in doubly distilled water at accumulation time of 360 sec using square wave voltammetry. The proposed method was also used for the determination of Hg (II) in drinking and tap water samples with very good recovery data and relative standard deviation of less than 3.5%. The designed sensor exhibited remarkable electrocatalytic effect by dramatically boosting the signal of the analyte as compared to the bare electrode. Computational studies of the interaction of DAN and mercury were also performed. The theoretical results were found in good agreement with the experimental findings.
Journal of Chemical Sciences, 2015
A novel thiourea-based non-ionic surfactant 1-(4-chlorophenyl)-3-dodecanoylthiourea (4CPDT) was s... more A novel thiourea-based non-ionic surfactant 1-(4-chlorophenyl)-3-dodecanoylthiourea (4CPDT) was synthesized from decanoyl chloride, potassium thiocyanate and 4-chloroanline in high yield. The structural chemistry of the compound was done by multiple nuclear NMR (1 H, 13 C) and FT-IR. UV-Visible spectrophotometry and pendant drop methods were used to evaluate their critical micelle concentration in ethanol and hexane. This surfactant showed very low solubility in water, and interestingly low but well-defined, submillimolar critical micelle concentration (CMC) in ethanol and hexane, demonstrating that this is moderately amphiphobic. Its low value of critical micelle concentration indicates economical use for cleaning purposes and environment-friendly applications. It was also characterized by cyclic and square wave voltammetry and found to be electrochemically active giving sharp signal in different pH media.
Comptes Rendus Chimie, 2015
Journal of The Electrochemical Society, 2014
![Research paper thumbnail of Redox Mechanism and Evaluation of Kinetic and Thermodynamic Parameters of 1,3-Dioxolo[4,5-g]pyrido[2,3-b]quinoxaline Using Electrochemical Techniques](https://attachments.academia-assets.com/117344623/thumbnails/1.jpg)
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Electrochimica Acta, 2014
The redox behavior of a novel quinoxaline carboxylic acid derivative, 6-(1-hydroxynaphthalen-2-yl... more The redox behavior of a novel quinoxaline carboxylic acid derivative, 6-(1-hydroxynaphthalen-2-yl) benzo[f]quinoxaline-2-carboxylic acid (HBQCA) was studied at the surface of glassy carbon electrode in a wide pH range using modern electrochemical techniques. Cyclic, square wave and differential pulse voltammetry were employed in this work. Several important thermodynamic parameters of the redox reactions of HBQCA were evaluated. Various physical parameters like apparent energy of activation, heterogeneous electron transfer rate constant and diffusion coefficient were also determined. On the basis of electrochemical results the pH dependent redox mechanism of HBQCA was proposed. Computational chemistry was used as a tool for the identification of oxidizable and reducible electropores and evaluation of some useful quantum chemical parameters for further characterization of the compound.
Journal of The Electrochemical Society, 2015
Arabian Journal of Chemistry, 2014
Journal of Photochemistry and Photobiology B: Biology, 2013
UV-Vis spectroscopic behavior of four imidazolidine derivatives i.e., [5-benzylideneimidazolidine... more UV-Vis spectroscopic behavior of four imidazolidine derivatives i.e., [5-benzylideneimidazolidine-2,4dione (NBI), 5-(2-hydroxybenzylidene)imidazolidine-2,4-dione (HBI), 5-(4-methoxybenzylidene)imidazolidine-2,4-dione (MBI) and 5-(3,4-di-methoxybenzylidene)imidazolidine-2,4-dione (DBI)] was studied in a wide pH range. Spectroscopic response of the studied compounds was found sensitive to pH and the attached substituents. Incited by anti-tumor activity, structural miscellany and biological applications of imidazolidines, the DNA binding affinity of some novel derivatives of this class of compounds was examined by cyclic voltammetry (CV) and UV-Vis spectroscopy at pH values of blood (7.4) and lysosomes (4.5). The CV results showed the following order of binding strength: K NBI (6.40 Â 10 6 M À1) > K HBI (1.77 Â 10 5 M À1) > K MBI (2.06 Â 10 4 M À1) > K DBI (1.01 Â 10 4 M À1) at pH 7.4. The same order was also obtained from UV-Vis spectroscopy. The greater affinity of NBI justified its preferred candidature as an effective anti-cancer drug. The DNA binding propensity of these compounds was found comparable or greater than most of the clinically used anticancer drugs.
Journal of Photochemistry and Photobiology B: Biology, 2012
The redox mechanism and electronic absorption behavior of a commercial anticancer drug, 5-fluorou... more The redox mechanism and electronic absorption behavior of a commercial anticancer drug, 5-fluorouracil (5-FU) and two potential anticancer drugs, 2-thiouracil (2-TU) and dithiouracil (DTU) have been investigated in a wide pH range by UV-Vis spectroscopy, cyclic voltammetry and differential pulse voltammetry. The effect of electrolytes, substituents, successive sweeps and potential scan rate on the voltammetric response of uracils was examined. Organized structure-activity relationships of these drugs were established on the basis of the results obtained from electronic absorption spectroscopy and cyclic voltammetry. The electrode reaction mechanism was suggested using the experimentally determined electrochemical parameters. The DNA binding propensity of uracils was found greater than the classical intercalator, proflavin and clinically used drug, epirubicin. Moreover, the results obtained through ab initio calculations for the oxidation potential of the three uracil derivatives were found in good agreement with the electrochemical results.
European journal of medicinal chemistry, Oct 1, 2009
Three new triorganotin(IV) dithiocarboxylates (1–3) with general formula R3SnL, where R=C4H9 (1),... more Three new triorganotin(IV) dithiocarboxylates (1–3) with general formula R3SnL, where R=C4H9 (1), C6H11 (2), C6H5 (3) and L=4-(4-nitrophenyl)piperazine-1-carbodithioate, have been synthesized and characterized by elemental analysis, Raman, FT-IR, multinuclear NMR (1H, 13C and 119Sn) and mass spectrometry. The crystal structure of complex 3 confirmed distorted trigonal-bipyramidal geometry around Sn atom. The interaction of compounds 1–3 with DNA was investigated by
Journal of the Electrochemical Society, 2014
ABSTRACT The electrochemical fate of ethylene diamine (ED) was probed at the surface a glassy car... more ABSTRACT The electrochemical fate of ethylene diamine (ED) was probed at the surface a glassy carbon electrode over a wide range of pH 2-12 using cyclic, differential pulse and square wave voltammetry. A single quasi-reversible anodic peak followed by a reversible voltammetric signature of the oxidized product was evidenced in the first and second scan cyclic voltammograms. The quasi-reversible nature of the electron abstraction process of ED was witnessed by the unequal anodic and cathodic peak currents, scan rate deviation of peak potential and the value of heterogeneous electron transfer rate constant. On the contrary, cyclic and square wave voltammetric results revealed the redox behavior of the oxidized product of ED to be reversible. The redox mechanism was proposed on the basis of the obtained results in order to offer useful guidelines for protection against the harmful effects of diamines. As the presence of diamines in aqueous system is a serious threat to living organisms so we developed and validated a sensitive, robust, specific and reproducible square wave voltammetric method for the rapid determination of low concentration of ED. The linearity was achieved within the concentration range from 30 to 100 M with LOD = 47.4 mu M. Precision was checked with recovery studies.
RSC Advances, 2022
Nanoparticles bind to the surface of the cell membranes of microbes altering their basic cell fun... more Nanoparticles bind to the surface of the cell membranes of microbes altering their basic cell functions and resulting in cell death.
European journal of medicinal chemistry, Oct 1, 2009
Three new triorganotin(IV) dithiocarboxylates (1–3) with general formula R3SnL, where R=C4H9 (1),... more Three new triorganotin(IV) dithiocarboxylates (1–3) with general formula R3SnL, where R=C4H9 (1), C6H11 (2), C6H5 (3) and L=4-(4-nitrophenyl)piperazine-1-carbodithioate, have been synthesized and characterized by elemental analysis, Raman, FT-IR, multinuclear NMR (1H, 13C and 119Sn) and mass spectrometry. The crystal structure of complex 3 confirmed distorted trigonal-bipyramidal geometry around Sn atom. The interaction of compounds 1–3 with DNA was investigated by
RSC Advances, 2022
Nanoparticles bind to the surface of the cell membranes of microbes altering their basic cell fun... more Nanoparticles bind to the surface of the cell membranes of microbes altering their basic cell functions and resulting in cell death.
Global Challenges, 2018
Electrochemical capacitors (ECs) are a vital class of electrical energy storage (EES) devices tha... more Electrochemical capacitors (ECs) are a vital class of electrical energy storage (EES) devices that display the capacity of rapid charging and provide high power density. In the current era, interest in using ionic liquids (ILs) in high‐performance EES devices has grown exponentially, as this novel versatile electrolyte media is associated with high thermal stability, excellent ionic conductivity, and the capability to withstand high voltages without undergoing decomposition. ILs are therefore potentially useful materials for improving the energy/power performances of ECs without compromising on safety, cyclic stability, and power density. The current review article underscores the importance of ILs as sustainable and high‐performance electrolytes for electrochemical capacitors.
Bioelectrochemistry, 2018
... Fouzia Perveen, Rumana Qureshi*, Afzal Shah, Safeer Ahmed, Farzana Latif Ansari, Saima Kalsoo... more ... Fouzia Perveen, Rumana Qureshi*, Afzal Shah, Safeer Ahmed, Farzana Latif Ansari, Saima Kalsoom and Sumera Mehboob ... Amtul, Z., Follmer, C., Mahboob, S., Rahman, AU, Mazhar, M.,Khan, KM, Siddiqui, RA, Muhammad, S., Kazmi, SA, and Choudhary, MI (2007) Germa-c ...
International journal of pharmaceutics, Jan 7, 2018
Various types of nanoparticles (NPs) have been used in delivering anticancer drugs to the site of... more Various types of nanoparticles (NPs) have been used in delivering anticancer drugs to the site of action. This area has become more attractive in recent years due to optimal size and negligible undesirable side effects caused by the NPs. The focus of this review is to explore various types of NPs and their surface/chemical modifications as well as attachment of targeting ligands for tuning their properties in order to facilitate targeted delivery to the cancer sites in a rate-controlled manner. Heme compatibility, biodistribution, longer circulation time, hydrophilic lipophilic balance for high bioavailability, prevention of drug degradation and leakage are important in transporting drugs to the targeted cancer sites. The review discusses advantages of polymeric, magnetic, gold, and mesoporous silica NPs in delivering chemotherapeutic agents over the conventional dosage formulations along with their shortcomings/risks and possible solutions/alternatives.
Electrochimica Acta, 2016
A highly sensitive electrochemical sensor based on immobilization of a newly synthesized urea fun... more A highly sensitive electrochemical sensor based on immobilization of a newly synthesized urea functionality containing surfactant, 1-(2, 4-dinitrophenyl)-dodecanoylthiourea (DAN), possessing soil fertility enhancing characteristics, was developed for the detection of Hg(II) using cyclic, square wave and differential pulse voltammetry. Under suitable experimental conditions, calibration plot with a good linearity up to 2 µg/L was obtained with a detection limit of 0.64 µg/L and sensitivity of 0.164 µAL/µg in doubly distilled water at accumulation time of 360 sec using square wave voltammetry. The proposed method was also used for the determination of Hg (II) in drinking and tap water samples with very good recovery data and relative standard deviation of less than 3.5%. The designed sensor exhibited remarkable electrocatalytic effect by dramatically boosting the signal of the analyte as compared to the bare electrode. Computational studies of the interaction of DAN and mercury were also performed. The theoretical results were found in good agreement with the experimental findings.
Journal of Chemical Sciences, 2015
A novel thiourea-based non-ionic surfactant 1-(4-chlorophenyl)-3-dodecanoylthiourea (4CPDT) was s... more A novel thiourea-based non-ionic surfactant 1-(4-chlorophenyl)-3-dodecanoylthiourea (4CPDT) was synthesized from decanoyl chloride, potassium thiocyanate and 4-chloroanline in high yield. The structural chemistry of the compound was done by multiple nuclear NMR (1 H, 13 C) and FT-IR. UV-Visible spectrophotometry and pendant drop methods were used to evaluate their critical micelle concentration in ethanol and hexane. This surfactant showed very low solubility in water, and interestingly low but well-defined, submillimolar critical micelle concentration (CMC) in ethanol and hexane, demonstrating that this is moderately amphiphobic. Its low value of critical micelle concentration indicates economical use for cleaning purposes and environment-friendly applications. It was also characterized by cyclic and square wave voltammetry and found to be electrochemically active giving sharp signal in different pH media.
Comptes Rendus Chimie, 2015
Journal of The Electrochemical Society, 2014
Electrochimica Acta, 2014
The redox behavior of a novel quinoxaline carboxylic acid derivative, 6-(1-hydroxynaphthalen-2-yl... more The redox behavior of a novel quinoxaline carboxylic acid derivative, 6-(1-hydroxynaphthalen-2-yl) benzo[f]quinoxaline-2-carboxylic acid (HBQCA) was studied at the surface of glassy carbon electrode in a wide pH range using modern electrochemical techniques. Cyclic, square wave and differential pulse voltammetry were employed in this work. Several important thermodynamic parameters of the redox reactions of HBQCA were evaluated. Various physical parameters like apparent energy of activation, heterogeneous electron transfer rate constant and diffusion coefficient were also determined. On the basis of electrochemical results the pH dependent redox mechanism of HBQCA was proposed. Computational chemistry was used as a tool for the identification of oxidizable and reducible electropores and evaluation of some useful quantum chemical parameters for further characterization of the compound.
Journal of The Electrochemical Society, 2015
Arabian Journal of Chemistry, 2014
Journal of Photochemistry and Photobiology B: Biology, 2013
UV-Vis spectroscopic behavior of four imidazolidine derivatives i.e., [5-benzylideneimidazolidine... more UV-Vis spectroscopic behavior of four imidazolidine derivatives i.e., [5-benzylideneimidazolidine-2,4dione (NBI), 5-(2-hydroxybenzylidene)imidazolidine-2,4-dione (HBI), 5-(4-methoxybenzylidene)imidazolidine-2,4-dione (MBI) and 5-(3,4-di-methoxybenzylidene)imidazolidine-2,4-dione (DBI)] was studied in a wide pH range. Spectroscopic response of the studied compounds was found sensitive to pH and the attached substituents. Incited by anti-tumor activity, structural miscellany and biological applications of imidazolidines, the DNA binding affinity of some novel derivatives of this class of compounds was examined by cyclic voltammetry (CV) and UV-Vis spectroscopy at pH values of blood (7.4) and lysosomes (4.5). The CV results showed the following order of binding strength: K NBI (6.40 Â 10 6 M À1) > K HBI (1.77 Â 10 5 M À1) > K MBI (2.06 Â 10 4 M À1) > K DBI (1.01 Â 10 4 M À1) at pH 7.4. The same order was also obtained from UV-Vis spectroscopy. The greater affinity of NBI justified its preferred candidature as an effective anti-cancer drug. The DNA binding propensity of these compounds was found comparable or greater than most of the clinically used anticancer drugs.
Journal of Photochemistry and Photobiology B: Biology, 2012
The redox mechanism and electronic absorption behavior of a commercial anticancer drug, 5-fluorou... more The redox mechanism and electronic absorption behavior of a commercial anticancer drug, 5-fluorouracil (5-FU) and two potential anticancer drugs, 2-thiouracil (2-TU) and dithiouracil (DTU) have been investigated in a wide pH range by UV-Vis spectroscopy, cyclic voltammetry and differential pulse voltammetry. The effect of electrolytes, substituents, successive sweeps and potential scan rate on the voltammetric response of uracils was examined. Organized structure-activity relationships of these drugs were established on the basis of the results obtained from electronic absorption spectroscopy and cyclic voltammetry. The electrode reaction mechanism was suggested using the experimentally determined electrochemical parameters. The DNA binding propensity of uracils was found greater than the classical intercalator, proflavin and clinically used drug, epirubicin. Moreover, the results obtained through ab initio calculations for the oxidation potential of the three uracil derivatives were found in good agreement with the electrochemical results.
European journal of medicinal chemistry, Oct 1, 2009
Three new triorganotin(IV) dithiocarboxylates (1–3) with general formula R3SnL, where R=C4H9 (1),... more Three new triorganotin(IV) dithiocarboxylates (1–3) with general formula R3SnL, where R=C4H9 (1), C6H11 (2), C6H5 (3) and L=4-(4-nitrophenyl)piperazine-1-carbodithioate, have been synthesized and characterized by elemental analysis, Raman, FT-IR, multinuclear NMR (1H, 13C and 119Sn) and mass spectrometry. The crystal structure of complex 3 confirmed distorted trigonal-bipyramidal geometry around Sn atom. The interaction of compounds 1–3 with DNA was investigated by
Journal of the Electrochemical Society, 2014
ABSTRACT The electrochemical fate of ethylene diamine (ED) was probed at the surface a glassy car... more ABSTRACT The electrochemical fate of ethylene diamine (ED) was probed at the surface a glassy carbon electrode over a wide range of pH 2-12 using cyclic, differential pulse and square wave voltammetry. A single quasi-reversible anodic peak followed by a reversible voltammetric signature of the oxidized product was evidenced in the first and second scan cyclic voltammograms. The quasi-reversible nature of the electron abstraction process of ED was witnessed by the unequal anodic and cathodic peak currents, scan rate deviation of peak potential and the value of heterogeneous electron transfer rate constant. On the contrary, cyclic and square wave voltammetric results revealed the redox behavior of the oxidized product of ED to be reversible. The redox mechanism was proposed on the basis of the obtained results in order to offer useful guidelines for protection against the harmful effects of diamines. As the presence of diamines in aqueous system is a serious threat to living organisms so we developed and validated a sensitive, robust, specific and reproducible square wave voltammetric method for the rapid determination of low concentration of ED. The linearity was achieved within the concentration range from 30 to 100 M with LOD = 47.4 mu M. Precision was checked with recovery studies.
RSC Advances, 2022
Nanoparticles bind to the surface of the cell membranes of microbes altering their basic cell fun... more Nanoparticles bind to the surface of the cell membranes of microbes altering their basic cell functions and resulting in cell death.