Department Of Chemistry

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Access to carbon nanofiber composite hydrated cobalt phosphate nanostructure as an efficient catalyst for the hydrogen evolution reaction
(Frontiers Media S.A., 2023-02-23T00:00:00) Ahmed, Imtiaz; Biswas, Rathindranath; Sharma, Rohit; Burman, Vishal; Haldar, Krishna Kanta
Attractive technology for producing sustainable hydrogen with water electrolyzers was foreseen as one of the most promising ways to meet the increasing demands of renewable resources and electricity storage. Mainly used for the efficient generation of H2, water electrolysis involving hydrogen evolution reactions (HERs) depends on efficient and affordable electrocatalysts. Hydrogen is an effective fuel that can be produced by splitting water. Hence, the search for highly efficient HER catalysts is a major challenge as efficient hydrogen evolution catalysts are sought to replace catalysts such as platinum. Here, we describe a low-cost and highly effective electrocatalyst for the proper incorporation of the HER electrocatalyst with low overpotential, effective charge transfer kinetics, low Tafel slope, and good durability. By using a simple hydrothermal approach to produce Co3(PO4)2.8H2O/CNF, it is possible to attach Co3(PO4)2.8H2O to the surface of carbon nanofibers (CNFs), which also exhibit remarkable HER activity at an overpotential of 133�mV and produce a current density of 10�mA/cm2 and a 48�mV/decade for the Tafel slope. Large electrochemical surface areas and easy charge transfer from Co3(PO4)2.8H2O to the electrode through conductive Co3(PO4)2.8H2O/CNF composites are the reasons for the improved performance of Co3(PO4)2.8H2O/CNF. Copyright � 2023 Ahmed, Biswas, Sharma, Burman and Haldar.
Acetyl oxime/azirine 1, 3-dipole and strategy for the regioselective synthesis of polysubstituted pyrroles via [3 + 2] cycloaddition with alkyne utilizing Fe2O3@cellulose catalyst
(Elsevier B.V., 2021-09-27T00:00:00) Dwivedi, Kartikey Dhar; Kumar, Bhupender; Reddy, Marri Sameer; Borah, Biplob; Nagendra Babu, J.; Chowhan, L. Raju
Fe2O3@cellulose catalyzed regioselective [3 + 2] cycloaddition of acetyl oxime with alkynes via 2H?azirines intermediate generated in situ in an aqueous ethanolic medium is described. The methodology is highly regioselective for the synthesis of polysubstituted pyrroles in good yield. The products were isolated without using any column chromatography. The catalyst could be separated by using an external magnet and the recovered catalyst could be reused for four consecutive cycles with negligible loss in its catalytic activity. Broad functional group tolerance, mild reaction condition, easily accessible starting materials, utilization of green reaction medium, recyclability of the catalyst up to further reaction without affecting the outcome of the reaction, gram-scale synthesis are some of the salient features of this strategy. � 2021 The Author(s)
Advancements in the development of multi-target directed ligands for the treatment of Alzheimer's disease
(Elsevier Ltd, 2022-04-05T00:00:00) Kumar, Naveen; Kumar, Vijay; Anand, Piyush; Kumar, Vinay; Ranjan Dwivedi, Ashish; Kumar, Vinod
Alzheimer's disease (AD) is a multifactorial irreversible neurological disorder which results in cognitive impairment, loss of cholinergic neurons in synapses of the basal forebrain and neuronal death. Exact pathology of the disease is not yet known however, many hypotheses have been proposed for its treatment. The available treatments including monotherapies and combination therapies are not able to combat the disease effectively because of its complex pathological mechanism. A multipotent drug for AD has the potential to bind or inhibit multiple targets responsible for the progression of the disease like aggregated A?, hyperphosphorylated tau proteins, cholinergic and adrenergic receptors, MAO enzymes, overactivated N-methyl-D-aspartate (NMDA), ?-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor etc. The traditional approach of one disease-one target-one drug has been rationalized to one drug-multi targets for the chronic diseases like AD and cancer. Thus, over the last decade research focus has been shifted towards the development of multi target directed ligands (MTDLs) which can simultaneously inhibit multiple targets and stop or slow the progression of the disease. The MTDLs can be more effective against AD and eliminate any possibility of drug-drug interactions. Many important active pharmacophore units have been fused, merged or incorporated into different scaffolds to synthesize new potent drugs. In the current article, we have described various hypothesis for AD and effectiveness of the MTDLs treatment strategy is discussed in detail. Different chemical scaffolds and their synthetic strategies have been described and important functionalities are identified in the chemical scaffold that have the potential to bind to the multiple targets. The important leads identified in this study with MTDL characteristics have the potential to be developed as drug candidates for the effective treatment of AD. � 2022 Elsevier Ltd
Ag-S Type Quantum Dots versus Superatom Nanocatalyst: A Single Sulfur Atom Modulated Decarboxylative Radical Cascade Reaction
(American Chemical Society, 2023-04-06T00:00:00) Meena, Sangeeta; Dastider, Saptarshi G.; Nishad, Chandra Shekhar; Jangid, Dilip Kumar; Kumar, Pankaj; Khirid, Samreet; Bose, Shubhankar Kumar; Mondal, Krishnakanta; Banerjee, Biplab; Dhayal, Rajendra S.
The preparation of high-nuclearity silver nanoclusters in quantitative yield remains exclusive and their potential applications in the catalysis of organic reactions are still undeveloped. Here, we have synthesized a quantum dot (QD)-based catalyst, [Ag62S13(SBut)32](PF6)4 (denoted as Ag62S12-S) in excellent yield that enables the direct synthesis of pharmaceutically precious 3,4-dihydroquinolinone in 92% via a decarboxylative radical cascade reaction of cinnamamide with ?-oxocarboxylic acid under mild reaction conditions. In comparison, a superatom [Ag62S12(SBut)32](PF6)2 (denoted as Ag62S12) with identical surface anatomy and size, but without a central S2- atom in the core, gives an improved yield (95%) in a short time and exhibits higher reactivity. Multiple characterization techniques (single-crystal X-ray diffraction, nuclear magnetic resonance (1H and 31P), electrospray ionization mass spectrometry, energy dispersive X-ray spectroscopy, Brunauer-Emmett-Teller (BET), Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis) confirm the formation of Ag62S12-S. The BET results expose the total active surface area in supporting a single e- transfer reaction mechanism. Density functional theory reveals that leaving the central S atom of Ag62S12-S leads to higher charge transfer from Ag62S12 to the reactant, accelerates the decarboxylation process, and correlates the catalytic properties with the structure of the nanocatalyst. � 2023 American Chemical Society.
[Ag20{S2P(OR)2}12]: A Superatom Complex with a Chiral Metallic Core and High Potential for Isomerism
(Wiley-VCH Verlag, 2016) Dhayal, R.S.; Lin, Y.-R.; Liao, J.-H.; Chen, Y.-J.; Liu, Y.-C.; Chiang, M.-H.; Kahlal, S.; Saillard, J.-Y.; Liu, C.W.
The synthesis and structural determination of a silver nanocluster [Ag20{S2P(OiPr)2}12] (2), which contains an intrinsic chiral metallic core, is produced by reduction of one silver ion from the eight-electron superatom complex [Ag21{S2P(OiPr)2}12](PF6) (1) by borohydrides. Single-crystal X-ray analysis displays an Ag20core of pseudo C3symmetry comprising a silver-centered Ag13icosahedron capped by seven silver atoms. Its n-propyl derivative, [Ag20{S2P(OnPr)2}12] (3), can also be prepared by the treatment of silver(I) salts and dithiophosphates in a stoichiometric ratio in the presence of excess amount of [BH4]?. Crystal structure analyses reveal that the capping silver-atom positions relative to their icosahedral core are distinctly different in 2 and 3 and generate isomeric, chiral Ag20cores. Both Ag20clusters display an emission maximum in the near IR region. DFT calculations are consistent with a description within the superatom model of an 8-electron [Ag13]5+core protected by a [Ag7{S2P(OR)2}12]5?external shell. Two additional structural variations are predicted by DFT, showing the potential for isomerism in such [Ag20{S2P(OR)2}12] species. ? 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Amido-amine derivative of alginic acid (AmAA) for enhanced adsorption of Pb(II) from aqueous solution
(Elsevier B.V., 2020) Vaid U.; Mittal S.; Babu J.N.; Kumar R.
The present work reports the alternate synthesis of amido-amine derivative of alginic acid (AmAA) with high degree of functionalization. The AmAA have been characterized for percentage functionalization, functional group change, surface morphology and thermal decomposition behavior. The results indicate that the amido-amine derivatisation of alginic acid (AA) with >95% functionalization, significantly improves its Pb(II) adsorption efficiency (395.72 mg/g to 535.87 mg/g) over the AA. The equilibrium and kinetic studies showed that Langmuir and Freundlich adsorption isotherm models fitted well to the experimental data, and these followed pseudo-second order kinetic model. The FTIR (Fourier transform infrared spectroscopy) and 13C CP-MAS NMR (Cross-polarization magic angle spinning carbon-13 solid state nuclear magnetic resonance spectroscopy) analysis revealed that Pb(II) binds to the carboxyl group in case of AA and to the carbonyl & amine group in case of AmAA, which leads to increase in its adsorption efficiency. The study concludes that the functionalization of amido-amine on AA improves its adsorptive efficiency for Pb(II) from aqueous medium.
Analysis of the effect of 1-Allyl-3-Methylimidazolium chloride on thermodynamic stability, folding kinetics, and motional dynamics of horse cytochrome c
(Elsevier B.V., 2022-09-08T00:00:00) Garg, Mansi; Sharma, Deepak; Kumar, Rajesh
1-allyl-3-methylimidazolium chloride (AMIMCl) acts as a potential green solvent for proteins. The present work provides a possible pathway by which the structural, kinetic, thermodynamic, and folding properties of horse cytochrome c (cyt c) are affected in green aqueous-AMIMCl systems. Analysis of the effect of AMIMCl on thermodynamic stability, refolding/unfolding kinetics, and motional dynamics of cyt c provided important information, (i) AMIMCl decreases the thermodynamic stability of reduced cyt c and also strengthens the guanidinium chloride (GdmCl)-mediated decrease in thermodynamic stability of protein, (ii) AMIMCl reduces the thermal-fluctuation of Met80-containing omega-loop of natively-folded compact state of carbonmonoxycytochrome c (MCO-state) due to polyfunctional interactions between the AMIM+ and different groups of protein, (iii) AMIMCl shifts the kinetic chevron plot, ln kobs[sbnd][GdmCl] to the lower concentration of GdmCl, (iv) AMIMCl shifts the refolding and unfolding limps to vertically downwards and upwards, respectively, and (v) AMIMCl reducing the unfolding free energy estimated by both thermodynamic and kinetic analysis. � 2022
Analysis of the pH-dependent thermodynamic stability, local motions, and microsecond folding kinetics of carbonmonoxycytochrome c
(Academic Press Inc., 2016) Kumar, Rajesh
This paper analyzes the effect of pH on thermodynamic stability, low-frequency local motions and microsecond folding kinetics of carbonmonoxycytochrome c (Cyt-CO) all across the alkaline pH-unfolding transition of protein. Thermodynamic analysis of urea-induced unfolding transitions of Cyt-CO measured between pH 6 and pH 11.9 reveals that Cyt-CO is maximally stable at pH?9.5. Dilution of unfolded Cyt-CO into refolding medium forms a native-like compact state (NCO-state), where Fe2+?CO interaction persists. Kinetic and thermodynamic parameters measured for slow thermally-driven CO dissociation (NCO?N+CO) and association (N+CO?NCO) reactions between pH 6.5 and pH 13 reveal that the thermal-motions of M80-containing ?-loop are decreased in subdenaturing limit of alkaline pH. Laser photolysis of Fe2+-CO bond in NCO-state triggers the microsecond folding (NCO?N). The microsecond kinetics measured all across the alkaline pH-unfolding transition of Cyt-CO produce rate rollover in the refolding limb of chevron plot, which suggests a glass transition of NCO en route to N. Between pH 7 and pH 11.9, the natural logarithm of the microsecond folding rate varies by?<?1.5 units while the natural logarithm of apparent equilibrium constant varies by 11.8 units. This finding indicates that the pH-dependent ionic-interactions greatly affect the global stability of protein but have very small effect on folding kinetics. ? 2016 Elsevier Inc.
Au/CdSe hybrid nanoflowers: a high photocurrent generating photoelectrochemical cells
(Springer, 2019) Haldar, Krishan Kant; Biswas, R; Patra, A; Halder, K.K; Sen, T.
Photoelectrochemical cell composed of solution-processed nanoflower heterostructure of Au core and eight CdSe petals was investigated for enhanced photocurrent generation. The electrode of CdSe nanorods displayed photocurrent density of 2.1 mA/cm 2 whereas the Au core CdSe nanoflower exhibited 4.6 mA/cm 2 corresponding to a 119% increase during photoelectrochemical cell performance. Both electrodes showed prompt response to the on/off cycles of light, the photocurrent gain (I Photon /I dark ) in CdSe nanorods is 124.7, while the value is 223.3 for Au/CdSe nanoflower, calculated from the growth-decay curves. Photoresponse time was dramatically improved for Au/CdSe nanoflower samples due to increasing in 66% incident photon-to-current emission. Electron lifetime of 21.63 and 48.71 ns was observed for the electrode of CdSe nanorods and Au/CdSe nanoflowers respectively. The prolonged electron lifetime in the case of the electrode of Au/CdSe nanoflowers was responsible for improving charge separation and as a consequence, higher photocurrent generation. © 2018, Springer Nature Switzerland AG.
BiFeO3/g-C3N4/f-CNF ternary nanocomposite as an efficient photocatalyst for methylene blue dye degradation under solar light irradiation
(Elsevier Ltd, 2023-06-21T00:00:00) Deeksha; Kour, Pawanpreet; Ahmed, Imtiaz; Haldar, Krishna Kanta; Yadav, C.S.; Sharma, Surender Kumar; Yadav, Kamlesh
The development of Perovskite oxide photocatalysts with superior dye degradation efficiency under solar light irradiation has gained attention in recent years, owing to their extraordinary flexibility, chemical composition, and tunability. Herein, we report the facile synthesis of a novel ternary composite composed of BiFeO3 (BFO) perovskite, g-C3N4, and functionalized carbon nanofibers (f-CNF), referred to as BFO/g-C3N4/f-CNF using a simple solution method as a photocatalyst to accelerate the degradation of methylene blue dye. Detailed structural and microstructural features confirm the formation of a ternary composite composed of BFO nanoparticles and f-CNFs mounted on g-C3N4 nanosheets. The photocatalytic activity of the sample for the degradation of methylene blue dye was studied in solar light using UV�visible spectroscopy. The BFO/g-C3N4/f-CNF ternary composite displays excellent photocatalytic activity with a degradation rate of 87 % after illumination for 120 min under solar light than BFO, g-C3N4, and binary composites BFO/g-C3N4 and BFO/f-CNF. The highest rate constant (k = 0.01675 min?1) for BFO/g-C3N4/f-CNF further confirms improved photocatalytic efficiency. The red shift in the UV�visible absorption spectrum of BFO/g-C3N4/f-CNF indicates a reduced band gap (1.9 eV) compared to that of pure BFO (2.28 eV) and g-C3N4 ( 2.72 eV). A decrease in the photoluminescence intensity of the ternary composite compared to that of BFO indicates the inhibition of photoexcited electron recombination which results in the availability of more charge carriers for the photocatalytic process. The enhanced efficiency of BFO/g-C3N4/f-CNF can be explained by the synergistic effect between BFO and g-C3N4 and the incorporation of f-CNF further promotes the migration rate of electrons from BFO to g-C3N4. � 2023 Elsevier B.V.
Bifunctional electrochemical OER and HER activity of Ta2O5 nanoparticles over Fe2O3 nanoparticles
(Royal Society of Chemistry, 2023-08-23T00:00:00) Ahmed, Imtiaz; Burman, Vishal; Biswas, Rathindranath; Roy, Ayan; Sharma, Rohit; Haldar, Krishna Kanta
Hydrogen production via electrocatalytic water splitting offers encouraging innovations for sustainable and clean energy production as an alternative to conventional energy sources. The improvement of extraordinarily dynamic electrocatalysts is of great interest for work on the performance of gas generation, which is firmly blocked due to the sluggish kinetics of the oxygen evolution reaction (OER). The development of highly efficient base metal catalysts for electrochemical hydrogen and oxygen evolution reactions (HER and OER) is a challenging and promising task. In the present work, a particle over particles of Fe2O3 and Ta2O5 was successfully produced by hydrothermal treatment. The prepared composite shows promising catalytic performance when used as an electrochemical catalyst for OER and HER in alkaline and acidic electrolytes with low overpotentials of 231 and 201 mV at 10 mV cm?2, small Tafel slopes of 71 and 135 mV dec?1, respectively, and good stability properties. The calculated electrochemical surface area (ECSA) for composites is five times higher than that of the original oxides. The result of the OER is significantly better than that of commercial IrO2 catalysts and offers a promising direction for the development of water-splitting catalysts. � 2023 The Royal Society of Chemistry.
Bio-assisted Synthesis of Au/Rh Nanostructure Electrocatalysts for Hydrogen Evolution and Methanol Oxidation Reactions: Composition Matters!
(American Chemical Society, 2023-08-11T00:00:00) Biswas, Rathindranath; Dastider, Saptarshi Ghosh; Ahmed, Imtiaz; Biswas, Sayani; Mondal, Krishnakanta; Haldar, Krishna Kanta
In the field of catalysis, bimetallic nanostructures have attracted much interest. Here, we discuss the effect of Au/Rh bimetallic composition-tuned nanostructure and electrocatalytic activity. A simple bio-assisted technique was used to fabricate multiple Au:Rh nanoplate ratios (25:75, 50:50, and 75:25). XRD and XPS studies show that both Au and Rh phases coexist in a bimetallic nanostructure, and electron microscopy confirms the formation of a triangle-shaped nanoplate. Au0.25Rh0.75 exhibited the maximum catalytic activity and good stability for hydrogen evolution reaction (HER) with an overpotential of 105 mV at a current density of 10 mA/cm2. On the other hand, Au0.50Rh0.50 exhibits a higher activity for methanol oxidation reaction (MOR) compared to the other compositions. Theoretical studies indicate that the electrocatalytic enhancement obtained for both HER and MOR relies on electronic modification effects of the surface, with the overall reaction energy profile being optimized due to Au/Rh d-band mixing. � 2023 American Chemical Society.
Br�nsted acid catalyzed mechanochemical�domino multicomponent reactions by employing liquid assisted grindstone chemistry
(Nature Research, 2023-01-25T00:00:00) Borah, Biplob; Swain, Sidhartha; Patat, Mihir; Kumar, Bhupender; Prajapat, Ketan Kumar; Biswas, Rathindranath; Vasantha, R.; Chowhan, L. Raju
Here, we have demonstrated a metal-free energy-efficient mechanochemical approach for expedient access to a diverse set of 2-amino-3-cyano-aryl/heteroaryl-4H-chromenes, tetrahydrospiro[chromene-3,4?-indoline], 2,2?-aryl/heteroarylmethylene-bis(3-hydroxy-5,5-dimethylcyclohex-2-enone) as well as tetrahydro-1H-xanthen-1-one by employing the reactivity of 5,5-dimethylcyclohexane-1,3-dione/cyclohexane-1,3-dione with TsOH?H2O as Br�nsted acid catalyst under water-assisted grinding conditions at ambient temperature. The ability to accomplish multiple C�C, C=C, C�O, and C�N bonds from readily available starting materials via a domino multicomponent strategy in the absence of metal-catalyst as well as volatile organic solvents with an immediate reduction in the cost of the transformation without necessitates complex operational procedures, features the significant highlights of this approach. The excellent yield of the products, broad functional group tolerances, easy set-up, column-free, scalable synthesis with ultralow catalyst loading, short reaction time, waste-free, ligand-free, and toxic-free, are other notable advantages of this approach. The greenness and sustainability of the protocol were also established by demonstrating several green metrics parameters. � 2023, The Author(s).
A cascade A3 coupling strategy towards the regioselective synthesis of ?-carboline N-fused pyrrole derivatives with pyridine tethers
(Royal Society of Chemistry, 2022-12-01T00:00:00) Vaishali, None; Malakar, Chandi C.; Singh, Virender
A potential three component reaction strategy has been devised to generate nature inspired ?-carboline N-fused pyrroles containing pyridine tethers. These scaffolds were afforded in high yields via a one-pot cascade regioselective reaction of diverse Kumujian C, 2-aminopyridines and alkyne derivatives under Cu(ii)-catalysis. A library of 32 novel indolizino[8,7-b]indole derivatives with pyridine tethers has been developed. The current protocol offers excellent regioselectivity, high atom-economy and significant structural diversity. � 2023 The Royal Society of Chemistry.
A Catalyst- and Metal-free Approach towards the Synthesis of ?-Carboline tethered Imidazole Derivatives and Assessment of their Photophysical Properties
(John Wiley and Sons Inc, 2023-04-25T00:00:00) Vaishali; Singh, Virender
A simple, facile, and highly efficient approach has been unfolded for the syntheses of ?-carboline tethered imidazole derivatives. This expeditious catalyst-free strategy proceeds through the assembly of 1-formyl-9H-?-carbolines, glyoxal derivatives and ammonium acetate via the formation of concomitant four C?N bonds in a one-pot operation. The current approach has various advantages, including multicomponent nature, simple reaction conditions, short reaction time, broad substrate scope, and high product yield. Importantly, the ?-carboline tethered imidazole derivatives displayed excellent photophysical properties with quantum yield up to 90%. � 2023 Wiley-VCH GmbH.
Charge Separated One-Dimensional Hybrid Cobalt/Nickel Phosphonate Frameworks: A Facile Approach to Design Bifunctional Electrocatalyst for Oxygen Evolution and Hydrogen Evolution Reactions
(American Chemical Society, 2021-09-30T00:00:00) Rom, Tanmay; Biswas, Rathindranath; Haldar, Krishna Kanta; Sarkar, Sourav; Saha, Uttam; Paul, Avijit Kumar
Two new organoamine templated one-dimensional transition metal phosphonate compounds are synthesized, and their bifunctional electrocatalytic activities are examined in highly alkaline and acidic media. Compared with state-of-the-art materials, the cobalt phosphonate system is a new fabrication of sustainable and highly efficient catalysts toward electrochemical water splitting systems. � 2021 American Chemical Society. All rights reserved.
Chitosan-supported copper as an efficient and recyclable heterogeneous catalyst for A3/decarboxylative A3-coupling reaction
(Elsevier Ltd, 2018) Kaur, Pavneet; Kumar, Bhupinder; Kumar, Vinod; Kumar, Rakesh
Chitosan-supported copper (chit@copper) based heterogeneous catalysts have been explored for A3-coupling and decarboxylative A3-coupling. The developed protocol employs low catalyst loading, solventless condition and easy work-up for the synthesis of diversely substituted propargylamines. More importantly, the catalyst could be recovered and reused without any significant loss in the activity. This offer huge advantages as recyclability issues are rarely addressed in decarboxylative A3-coupling. Leaching studies were carried out using AAS and ICPMS analysis. It is envisaged that chit@copper catalysts can have potential applications in terms of efficiency and recyclability in the emerging area of decarboxylative C?H bond activation/functionalization strategies. ? 2018 Elsevier Ltd
Chitosan-supported FeCl3 catalyzed multicomponent synthesis of tetrahydroisoquinoline-indole hybrids with promising activity against chloroquine resistant Plasmodium falciparum
(Elsevier B.V., 2022-10-26T00:00:00) Kaur, Pavneet; Sharma, Priyanka; Kumar, Vinod; Sahal, Dinkar; Kumar, Rakesh
An operationally simple three-component coupling of tetrahydroisoquinoline (THIQ), aldehydes and indoles or indole-3-carboxylic acids has been achieved using chitosan-ionic liquid supported FeCl3 (chit-IL@FeCl3) as a recyclable heterogeneous catalyst. The developed waste-free approach provided rapid access to biologically important THIQ-indole hybrids without the use of any additive or ligand. The synthesized THIQ-indole hybrids were evaluated as antiplasmodial agents against chloroquine-sensitive (Pf3D7) and chloroquine-resistant (PfINDO) strains of Plasmodium falciparum. Compounds 4b (most potent against Pf3D7) and 4g (most potent against PfINDO) showed IC50 values of 1.32 and 0.26 �g/mL respectively. Also, 4g showed strong cytocidal action against both rings and trophozoite stages. Furthermore, cytotoxic study against human liver HUH 7 cells revealed that the most potent compound 4g with an excellent resistance index of 0.07 is also relatively non-toxic. The results of this study suggest that THIQ-indole hybrids hold an enormous potential for developing new antimalarial agents with novel mechanism of action. � 2022 Elsevier B.V.
Comprehensive Update on Synthetic Aspects of Bosentan Derivatives
(Bentham Science Publishers, 2022-05-11T00:00:00) Panchal, Jigar; Panchal, Ashima; Jain, Sonika; Jain, Pankaj Kumar; Dwivedi, Jaya; Sharma, Swapnil
Bosentan and its analogues were first reported as endothelin (ET) receptor antagonists in US patent No. 5, 292,740 in 1994. Bosentan synthesis has been reported by employing different methods from the reaction between (4,6-dichloro-5-(2-methoxyphenoxy)-2,2'-bipyrimidine and 4-(tert-butyl) benzenesulfonamide and 4-(tert-butyl)-N-(6-chloro-5-(2-methoxyphenoxy)-[2,2'-bipyrimidin]-4-yl) benzenesulfonamide in the form of different salts like potassium salt, ammonium salt, sodium salt, and free, on its reaction with ethylene glycol. Several changes have been observed in the chemistry of the involved intermediate synthesis, particularly coupling chemistry, to produce bosentan derivatives with high purity and yield. � 2023 Bentham Science Publishers.
Construction of three-dimensional marigold flower-shaped Ni3V2O8 for efficient solid-state supercapacitor applications
(John Wiley and Sons Inc, 2022-06-13T00:00:00) Haldar, Krishna K.; Biswas, Rathindranath; Arya, Anil; Ahmed, Imtiaz; Tanwar, Shweta; Sharma, Achchhe Lal
Development of binary spinel-type mixed metal oxide and fabrication various morphological heterostructure nanomaterials having two distinct metals paid a wide attention in emerging field. Here, we prepared three-dimensional (3D) marigold flower-like Ni3V2O8 structure via a simple and facile technique for electrochemical supercapacitor applications. 3D Ni3V2O8 with thick petals as cathode materials exhibits high specific capacitance of 263.12 F g?1 at a scan rate of 0.5�mA cm?2. The high energy density of 32.98 W h kg?1 at power density of 189.96 W kg?1 is obtained by the cathode formation of marigold flower-shaped Ni3V2O8, indicating excellent ions accessibility and large charge storage ability of Ni3V2O8 structure. It is also observed that even after 5000 cycles charging-discharging profile analysis, Ni3V2O8 cathode retains 32% of its initial capacitance along with 100% Coulombic efficiency. This higher capacitance retention strengthens its adoption as a potential candidate for supercapacitor application. � 2022 John Wiley & Sons Ltd.