Publications

Synthesis Crystal Structure and Spectral Properties of New Sulfonamides

Anticoagulation activity of sulfated carboxymethyl cellulose/<i>Azadirachta indica</i> leaf powder-based bio-composite

Polymeric bio-composites synthesized <i>via</i> a green approach using natural herbs have fascinating anticoagulant activity due to their eco-friendly and non-toxic behavior towards various physical and chemical actions. Herein, we introduce a simple and eco-friendly approach for the fabrication of a new hybrid type of bio-composite based on sulfated carboxymethyl cellulose (S-CMC) and <i>Azadirachta indica</i> leaf powder (S-CMC/NLP). First, a non-toxic sulfating agent called N(SO₃Na)₃ was used to modify carboxymethyl cellulose into S-CMC. With an ion exchange capacity of 0.25 meq. g^-1, the level of sulfation (%) of S-CMC (modified polysaccharide) was measured to be 12.01%. Three types of S-CMC/NLP bio-composites were developed by varying the concentration of NLP. FE-SEM, EDX, and XRD were used to characterize the structural features of S-CMC/NLP bio-composites. FTIR spectroscopy indicated that the S-CMC/NLP bio-composite possesses COO^-, -OH and SO^3- groups, suggesting the structural similarity to heparin. In addition, the anticoagulant effect of the S-CMC/NLP bio-composite was investigated using PT and APTT assays. The APTT investigation confirmed that following the intrinsic pathway of the coagulation system, 2-NLP/S-CMC bio-composite dose-dependently (0.045-0.28 mg mL^-1) prolonged the time of blood coagulation compared to control (pure plasma). The S-CMC/NLP bio-composite showed its potential as a new, safe, and effective candidate for anticoagulant activity.

Bamboo-like nitrogen-doped carbon nanotubes toward fluorescence recovery assay for DNA detection

α,β-Enone Borylation by Bis(Pinacolato)Diboron Catalyzed by Cu3(BTC)2 Using Cesium Carbonate as a Base

Cu₃(BTC)₂ (BTC: 1,3,5-benzenetricarboxylate) as a heterogeneous catalyst in the presence of cesium carbonate as a base is reported for the borylation of α,β-conjugated enones by bis(pinacolato)diboron (B₂pin₂). According to the hot-filtration test, Cu₃(BTC)₂ is acting as a heterogeneous catalyst. Further, Cu₃(BTC)₂ exhibits a wide substrate scope and can be reused in consecutive runs, maintaining a crystal structure as evidenced by powder X-ray diffraction (XRD). A suitable mechanism is also proposed for this transformation using Cu₃(BTC)₂ as catalyst.

Multi-step synthesis, spectroscopic studies of biological active steroidal thiosemicarbazones and their palladium (II) complex as macromolecules

Effect of cellulose nano fibers and nano clays on the mechanical, morphological, thermal and dynamic mechanical performance of kenaf/epoxy composites

Contributors

Selective detection of divalent nickel ions based on wet-chemically prepared Cs-doped ZnO nanosheets

Gold(I)‐Catalyzed Cycloisomerization of 3‐Alkoxyl‐1,6‐diynes: A Facile Access to Bicyclo[2.2.1]hept‐5‐en‐2‐ones

A novel gold-catalyzed cycloisomerization of 1,6-diynes was achieved, providing an atom-economic approach to a diverse set of bicyclo[2.2.1]hept-5-en-2-ones in moderate to good yields. With unsymmetrical starting materials with two different internal alkynyl substituents, to some extent, the regioselectivity could be controlled by both electronic and steric factors. This unprecedented reactivity pattern may inspire new and unconventional strategies for the preparation of bridged ring systems.

Novel dyes derived from hydrazones: Part 3. Synthesis and characterizations of 2-[4-(1-phenylethylidene)hydrazino]phenylethylene-1,1,2-tricarbonitrile

Ni foam: a novel three-dimensional porous sensing platform for sensitive and selective nonenzymatic glucose detection

The present communication reports on the first use of commercially available three-dimensional porous Ni foam (NF) as a novel electrochemical sensing platform for nonenzymatic glucose detection. NF not only acts as a working electrode, but also functions as an effective electrocatalyst for electrooxidation of glucose. The sensor exhibits high selectivity toward glucose. The linear range and limit of detection were 0.05-7.35 mM (R = 0.995) and 2.2 μM with a signal-to-noise ratio of 3, respectively. The application of this glucose sensor in human blood serum has also been demonstrated successfully.

Thermodynamic aspects of polymer–surfactant interactions: Gemini (16-5-16)-PVP-water system

The interaction between polyvinylpyrrolidone (PVP) and gemini surfactant (16-5-16) in aqueous solution has been analyzed using conductometry. From conductivity data the critical aggregation concentration (cac), critical micelle concentration (cmc), the effective degree of counter-ion binding (β) at different temperatures were obtained. The thermodynamic parameters, i.e., Gibbs energy of aggregation and micellization, standard enthalpy of aggregation, and standard entropy of aggregation of surfactant/polymer system were estimated, employing pseudophase separation model. The negative values of Gibbs energy and standard enthalpy suggest that the surfactant/polymer aggregation process is spontaneous and exothermic respectively.

Controllable synthesis of SnO₂@C yolk–shell nanospheres as a high-performance anode material for lithium ion batteries

In this work, we report a facile synthesis of uniform SnO2@C yolk-shell nanospheres as high-performance anode materials for lithium ion batteries (LIBs). The yolk-shell structured SnO2@C nanospheres were fabricated through a two-step sol-gel coating process by using tetraethyl orthosilicate (TEOS) and resorcinol-formaldehyde (RF) as precursors, where the silica interlayer not only acts as a template to produce the void space, but also promotes the coating of the RF layer. The synthesis is easy to operate and allows tailoring the carbon shell thickness and void space size. The resultant SnO2@C yolk-shell nanospheres possess a hollow highly crystalline SnO2 core (280-380 nm), tailored carbon shell thickness (15-25 nm) and a large void space size (100-160 nm), a high surface area (∼205 m(2) g(-1)), a large pore volume (∼0.25 cm(3) g(-1)), as well as a high SnO2 content (77 wt%). When evaluated as an anode of LIBs, the materials manifest superior electrochemical performance with a high lithium storage capability (2190 mA h g(-1) in initial discharge capacity; >950 mA h g(-1) in the first 10 cycles), a good cycling performance and an excellent rate capability.

Theoretical and Experimental Investigations of <i>N</i> ‐ and <i>O</i> ‐Alkylated Sulfonamides: Density Functional Theory, Hirshfeld Surface Analysis, and Molecular Docking Studies

Abstract The current article is based on the synthesis of new N ‐ and O‐ alkylated sulfonamides; 4‐{[Ethyl‐(naphthalene‐2‐sulfonyl)‐amino]‐methyl}‐cyclohexanecarboxylic acid ethyl ester ( IV ), 4‐[(2‐nitrobenzene‐1‐sulfonylamino)‐methyl]‐cyclohexanecarboxylic acid ethyl ester ( V ) and 4‐[(Cyclohexa‐1,5‐dienesulfonylamino)‐methyl]‐cyclohexanecarboxylic acid methyl ester ( VI ). These compounds were characterized by FT‐IR spectroscopy, ESI‐MS spectrometry, and X ‐ray crystallography. Density functional theory (DFT) of sulfonamide esters was carried out through the Gaussian‐09 program to optimize structures. Hirshfeld surface analysis has been performed to understand the intermolecular interactions. Biological evaluation of all compounds was done to check their application for antibacterial ( Halomonas halophila, Shigella sonnei, Bacillus subtilis, Chromohalobacter salexigens, Staphylococcus aureus Escherichia coli, Serratia marcescens, Chromohalobacter israelensis, Nesseria gonorrhoeae , Klebsiella pneumonia , and Halomonas salina) , anti‐fungal ( Aspergillus niger ), enzyme inhibition activity (Acetylcholine esterase and butyrylcholine esterase) and anti‐oxidant activity (DPPH (2,2‐diphenyl‐1‐picrylhydrazyl) scavenging method, were carried out. Molecular docking was performed to check the interaction modes of these sulfonamide esters.

A Combined Experimental and Computational Investigation on Spectroscopic and Photophysical Properties of a Coumarinyl Chalcone

In‐situ Glycine Sensor Development Based ZnO/Al ₂ O ₃ /Cr ₂ O ₃ Nanoparticles

Abstract Initially, low‐dimensional ternary nanoparticles of ZnO/Al 2 O 3 /Cr 2 O 3 were synthesized using reliable solvothermal process and successfully implemented to fabricate enzyme‐less selective glycine (Gly) sensor. The calibration curve was plotted from the linear relation of current versus concentration of glycine. By using the slope of resultant calibration curve, the sensitivity (2.09*10 2 μAμM −1 cm −2 ) of Gly sensor was estimated by considering the active surface area of fabricated sensor probe. The proposed enzyme‐free Gly biosensor was found linear over large concentration range of 0.1 nM ∼ 1.0 μM, known as linear dynamic range (LDR). The detection limit (82.25±4.11 pM) was calculated at signal to noise ratio of 3 from the calibration curve. The proposed enzyme‐less Gly sensor was exhibited good reproducibility, long‐term stability and efficiency to detect Gly in real biological samples by electrochemical approach. Thus, this novel research methodology might be a good technique for the development of enzyme‐less sensor using ternary metal oxide nanoparticles onto GCE for the biomedical applications.

Azomethines, isoxazole, N-substituted pyrazoles and pyrimidine containing curcumin derivatives: Urease inhibition and molecular modeling studies

Carbon nanotube- and graphene-based advanced membrane materials for desalination