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Here we report bio-functionalized magnetite nanoparticles (MNPs) for the adsorptive removal of U(vi). Over 94% adsorption is still retained ever after 4th cycle. The experimental adsorption was also investigated and supported by DFT calculations.

The assembly of an inclusion complex in an aqueous medium using a metabolizer drug (dyphylline) as guest and β-cyclodextrin as host has been established, which is extremely appropriate for a variety of applications in modern biomedical sciences. The formation of the inclusion complex is established by

The co-evaporation approach was used to examine the host-guest interaction and to explore the cytotoxic and antibacterial properties of an important anti-cancer medication, 6-mercaptopurine monohydrate (6-MP) with β-cyclodextrin (β-CD). The UV-Vis investigation confirmed the inclusion complex's (IC) 1 : 1 stoichiometry and was also utilized to oversee the viability of this inclusion process. FTIR, NMR, and XRD, among other spectrometric techniques, revealed the mechanism of molecular interactions between β-CD and 6-MP which was further hypothesized by DFT to verify tentative outcomes. TGA and DSC studies revealed that 6-MP's thermal stability increased after encapsulation. Because of the protection of drug 6-MP by β-CD, the formed IC was found to have higher photostability. This work also predicts the release behavior of 6-MP in the presence of CT-DNA without any chemical changes. An evaluation of the complex's antibacterial activity

Background and aim Epithelial ovarian cancer has the deadliest prognosis amongst gynaecological cancers, warranting an unmet need for newer drug targets. Based on its anticancer as well as abortifacient potential, Moringa oleifera Lam. root was hypothesized to have some implications in follicle stimulating hormone receptor (FSHR) dependent cancers like epithelial ovarian cancer. Experimental procedure Effect of Moringa oleifera Lam. root extract (MRE) was studied in epithelial ovarian cancer cell line through in vitro studies viz. MTT assay, clonogenic assay, cell cycle analysis, flow cytometry, western blot analysis, immunocytochemical analysis of FSHRand c-Myc expression and in vivo studies viz. effect of MRE in mice model of ovarian carcinoma. The structure of the active compound of MRE was elucidated following solvent extraction, purification through column chromatography, preparative TLC and bioactivity guided structural identification through 1H-NMR, 13C-NMR, DEPT-135, ESIMS,FT-IR spectrophotometry, UV–vis–NIR spectrophotometry and DFT study. Results and conclusion Crude MRE displayed cytotoxic activity, induced apoptosis, and attenuated expression of FSHR and c-Myc in ovarian cancer cell line OAW42. MRE also attenuated expression of CD31, FSHR, and c-Myc in tumour xenograft mouse model. Finally, the active compound purified from ethyl acetate-n-hexane subfraction ofMRE, that attenuated viability of ovarian carcinoma cell lines and reduced FSHR and c-Myc expression, was identified as a naturally hydrated-trifattyglyceride, showing aDFT-optimized folded amphipathic structure for easy transportation through hydrophilic and hydrophobic regions in a biological system, indicating its immense therapeutic relevance in epithelial ovarian carcinoma.

Herein, catalyst-free, eco-friendly, photo-triggered, self-degradation of malachite green (MG) and crystal violet (CV) dyes in comparison to photocatalytic degradation were investigated. To the best of our knowledge, this is the first systematic study to demonstrate the reactive oxygen species (ROS), electron (e−) and hole (h+) generation ability of dyes to initiate self-degradation in the presence of direct solar energy (a free source of UV radiation) and UV light (254 and 365 nm). Various experimental conditions, e.g., different dye concentrations, pH, vessel-materials (borosilicate glass and quartz) were optimized to achieve the optimum degradation outcomes. The degradation kinetics of dyes suggested the applicability of second-order-kinetics to all kinds of applied light sources. Investigation of the thermodynamic approach reveals that the self-degradation procedure was endothermic, with activation energies of 46.89 and 52.96 kJ mol−1, respectively, for MG and CV. The self-degradation mechanism was further corroborated by the quantum calculations, while the formation of final degraded products for dye-degradations was established on the basis of mass spectroscopy and total organic carbon (TOC) analysis. The computed emission energies for MG and CV advocate that the excitation energy occurs due to the sole-attribution electron excitation from the Highest Occupied Molecular Orbital (HOMO) to the Lowest Unoccupied Molecular Orbital (LUMO). The close energy difference between the hydroxyl anions and the dyes also facilitates the creation of the hydroxyl radical. In a similar manner, the excited electrons from the aforementioned dyes may readily be transferred to triplet molecular oxygen, which makes it possible to generate super oxide. The radical generated in the process facilitates the self-degradation of the dyes.

The Coronavirus disease-2019 (COVID-19), has become a worldwide pandemic and the scientific communities are struggling to find out the ultimate treatment strategies against this lethal virus, Severe Acute Respiratory Syndrome Coronavirus–2 (SARS-CoV-2). Presently, there is no potential chemically proven antiviral therapy available in the market which can effectively combat the infection caused by this deadly virus. Few vaccines are already developed but it is not clear to the scientific community how much efficient they are to combat SARS-CoV-2. Mode of transmission and symptoms of the disease are two important factors in this regard. Rapid diagnosis of the COVID-19 is very much important to stop its spreading. In this scenario, a complete study starting from symptoms of the disease to vaccine development including various SARS-CoV-2 detection techniques is very much required. In this review article, we have made a partial analysis on the origin, virology, global health, detection techniques, replication pathways, doses, mode of actions of probable drugs, and vaccine development for SARS-CoV-2.

Magnetic CoFe2O4-gC3N4 nanocomposites were successfully synthesized, and their photocatalytic activities toward the decomposition of model synthetic dyes (e.g., methylene blue, methyl orange, and Congo red) in the presence of H2O2 were evaluated under simulated solar light irradiation. The 50CoFe2O4-50gC3N4 nanocomposite exhibited the highest catalytic activity. The catalytic activity of 50CoFe2O4-50gC3N4 toward the photodegradation of some industrially used dyes (such as Drimaren Turquoise CL-B p, Drimaren Yellow CL-2R p, and Drimaren Red CL-5B p) was also examined, and the catalyst exhibited its capability to decompose the industrial dyes completely. An aqueous mixture of these dyes was prepared to mimic the dye-containing wastewater, which was fully photodegraded within 30 min. 50CoFe2O4-50gC3N4 also exhibited facile magnetic separability from the reaction mixture after the accomplishment of photocatalysis reaction and stable performance after five cycles. The high photocatalytic efficiency to degrade several dyes, including dyes used in textile industries, under solar light irradiation makes 50CoFe2O4-50gC3N4 a promising photocatalyst for the treatment of dye-containing wastewater discharged from industries.

Tridecanoic acid (TDA), an antimicrobial compound, was isolated from Bacillus sp. LBF-01 and purified with the help of column and multidimensional liquid chromatography (MDLC), and characterized by Thin-layer chromatography (TLC), Electrospray Ionisation Mass Spectrometry (ESI–MS), Ultraviolet–Visible (UV–Vis), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance (NMR) spectroscopic studies. Isolated TDA was potentialized through the synthesis of silver nanoparticles (AgNPs). UV–Vis, FTIR, and TEM analysis showed that synthesized AgNPs were stable, monodispersed, and spherical shape of average 19 nm diameter. Theoretical simulation using Density Functional Theory revealed that AgNPs were stabilized by the tridecanoate form of TDA with a binding energy of 59.9 kJ/mol. Both TDA and AgNPs showed strong antifungal and antibacterial activities against the plant and human pathogenic organisms, however, AgNPs showed higher antimicrobial efficacy than TDA. Synergistic activity of TDA and AgNPs with a fungicide (Bavistin) and antibiotics (Streptomycin and Ciprofloxacin) showed enhanced antimicrobial potency in the range of 20–32%. TDA and AgNPs cause severe morphological abnormalities in Fusarium oxysporum as observed under the light microscope. Hence, the study reveals that the antimicrobial TDA produced by Bacillus sp. LBF-01 have disease control potentiality, and also the TDA stabilized AgNPs have much higher antimicrobial efficacy against the target pathogens that could be utilized in plant and human diseases control.

Herein we have investigated the ability of the (6,6) MoS2-nanotube (NT) to sense environmentally hazardous electrophilic and nucleophilic gases using density functional theory (DFT). CO, CO2, H2O and NH3 gases were chosen for adsorption on the (6,6) MoS2-NT and different adsorption parameters such as adsorption energy, projected density of states (PDOS), band structure and structural changes after adsorption were evaluated. Nucleophilic gases NH3 and H2O showed a fairly high amount of electron density transfer from gas molecules to the NT while the opposite trend was realized for electrophilic gases CO and CO2. Among the four gases, H2O has the highest amount of adsorption energy (−1.74 eV) and a moderately high amount of charge transfer from H2O to the NT. Gas sensing behaviour was further rationalized from the enhanced I–V characteristics of gas adsorbed nanotubes compared to pristine ones. Analysis of results revealed that the (6,6) MoS2-NT showed a decent level of gas sensing properties towards CO, CO2, H2O and NH3 gases, and high selectivity for H2O makes the MoS2-NT superior to previously reported MoS2-monolayer in this matter. These results suggest the possibility of fabrication of highly efficient MoS2-NT based gas sensors for environmentally hazardous gases.

Flexible all-solid-state supercapacitors having high mechanical stability and foldable features are crucial to meet the growing demands for a large number of portable electronic devices such as wearable electronics, displays, touch screens, detectors, etc. Here, we report the fabrication of such a flexible all-solid-state asymmetric supercapacitor device by using a nanocomposite composed of a snowflake-like dendritic CoNi alloy and reduced graphene oxide ((CoNiD)60-rGO40) as the positive electrode and pure rGO as the negative electrode for the first time. In this device, a polyvinyl alcohol (PVA) gel containing 3 M KOH and 0.1 M K4[Fe(CN)6] was used as the electrolyte cum separator. This supercapacitor device offers a high energy density value of 52.8 Wh kg-1 at a power density of 2000 W kg-1. The values of these two key performance parameters are superior to the many commercially available supercapacitors and reported values in the literature. In addition, this device also exhibits retention of ∼95% of its initial specific capacitance value after 4000 cycles at a current density of 2.5 A g-1, displaying its high cycling stability. This supercapacitor is so flexible that no mechanical deformation occurs even after bending at different angles and folding up to 180°, and its specific capacitance value practically remains unaffected when the device was twisted at different bending angles. This flexible all-solid-state asymmetric supercapacitor device can power a light-emitting diode (LED) and demonstrates its promise to meet the practical applications in energy storage technology.

This brief presents a sub-2 dB noise figure (NF) packaged wideband receiver front-end for high sensitivity multi-standard radio. An inductive source degeneration technique with a low- $V_{T}$ CMOS transistor is adopted in composite pair low noise amplifier (CPLNA) to extend the bandwidth and to improve the NF, a current commutating multi-gate transistor pair (MGTR) down conversion passive mixer for better linearity of the packaged receiver. Fabricated in 65 nm CMOS technology, the receiver provides a maximum conversion voltage gain of 37 dB and NF of 1.85–2 dB with a 3 dB bandwidth from 0.3 GHz to 3 GHz in quad-flat no-leads (QFN) package. The receiver has a third-order intermodulation intercept point (IIP3) of −7 dBm at 2 GHz and consumes a 44.5 mW power (LNA + Mixer).

The energy demand, the crisis of fossil fuels, and the increasing popularity of portable and wearable electronics in the global market have triggered the demand to develop high-performance flexible all-solid-state supercapacitors that are capable of delivering high energy at high power density as well as being safely entrenched in those electronics. Herein, we have designed a nanocomposite, 80CF

Objectives: The present study aims to report on the production optimization, purification, and characterization of structural and functional attributes of a novel broad-spectrum antibacterial compound produced by Aspergillus fumigatus nHF-01 (GenBank Ac. No. MN190286).Materials and Methods: The culture conditions were optimized by using rigorous culture-set preparation considering various abiotic and biotic factors for a higher amount of antimicrobial production. The produced antimicrobial was solvent extracted and purified by preparative TLC and HPLC methods followed by characterization using UV-Vis, FT-IR, ESI-MS, and 1H-NMR spectroscopy. The MIC and MBC of the antimicrobials were determined against a set of Gram-positive and Gram-negative human pathogenic bacteria. The mode of action on cellular morphology and integrity were determined by LDH and SEM studies. Its biofilm-inhibition properties and synergistic activity with antibiotics were studied. The possible cytotoxic effect on human cell lines was also tested by MTT assay. The putative target site of action was evaluated through in silico molecular docking study. Results: The micro-fungus A. fumigatus nHF-01 produced the maximum antibacterial compound while grown in a combination of 2% MEB (w/v) and 4% YE (w/v) at pH 6.0 and 20 °C temperature with 100 rpm agitation for ten days. The DCM extractable crude compound has a potent growth inhibition against the target human food and topical pathogenic bacteria at a 15 mg/ml concentration and is stable up to 100 °C. The spectroscopic studies confirmed the antimicrobial compound as 5-butyl-2-pyridine carboxylic acid with MIC values from 0.069±0.0034 to 1.12±0.052 mg/ml and from 8.925±0.39 to 17.85±0.78 mg/ml; and MBC values from 8.925±0.40 to 17.85±0.776 mg/ml and from 0.069±0.0034 to 0.139±0.0065 mg/ml against human pathogenic Gram-positive and Gram-negative bacteria, respectively. A concentration of 0.139 and 17.85 mg/ml decreased the viability sharply within 15 min of the incubation period with the gradual increase in LDH activity, indicating a robust bactericidal and lytic mode of action. The time-kill kinetics study shows that at a 17.85 mg/ml dose (i.e. MBC), the compound caused zero viability of E. coli and S. epidermidis cells from the initial log CFU/ml 5.78 after 15 h of treatment. It caused a remarkable change in morphology like the formation of blebbing, notch, rupture of the entire cell walls, and entire dissolution of cell integrity at a concentration of 4 µg/ml and 129 µg/ml. It had cytotoxicity against the tested human lung carcinoma A549 cell line. It showed a notable antibiofilm activity at 20 µg/ml and 4 µg/ml comparable to the standard antibiofilm drug usnic acid 10 µg/ml and 64 µg/ml against E. coli and B. cereus. It had a synergistic activity with streptomycin, whereas ciprofloxacin and vancomycin showed additive effects. It showed the highest binding affinities with Quinol-Fumarate Reductase (1l0v), a respiratory enzyme. Conclusion: Thus, the above findings can be concluded that the strain A. fumigatus nHF-01 produces a novel broad-spectrum antimicrobial compound 5-butyl-2-pyridine carboxylic acid with potent bactericidal activity against human food and topical pathogenic bacteria. This is the first report of such a compound from the A. fumigatus.

The present study aims at the production optimization, purification, and characterization of a potent broad-spectrum antimicrobial compound (AMC) produced by Aspergillus fumigatus nHF-01 (GenBank Ac. No. MN190286). The culture conditions were optimized for a higher amount of AMC. The AMC was solvent extracted and characterized by UV–Vis, FT–IR, ESI–MS, and 1H-NMR spectroscopy. The MIC, MBC and mode of action were determined against a set of Gram-positive and Gram-negative human pathogenic bacteria. Its antibiofilm, synergistic and cytotoxic effects were also tested. The putative target site of action was evaluated through in silico molecular docking study. The stain A. fumigatus nHF-01 produced the maximum AMC (5-butyl-2-pyridine carboxylic acid) in 2% MEB (w/v) and 4% YE (w/v) at pH 6.0 and 20 °C temperature with 100 rpm agitation for ten days. It caused complete lethality of the Gram-positive and Gram-negative human pathogenic bacteria at a 129 µg/mL dose by rupture and entire dissolution of cell integrity. It showed moderate antibiofilm activity and had a synergistic activity with streptomycin and additive effects with ciprofloxacin and vancomycin. It targets a respiratory enzyme, Quinol-Fumarate Reductase (1l0v), with the highest binding affinities. It had cytotoxicity against human lung carcinoma A549 cell line and was stable up to 100 °C. Thus, the study revealed that the strain A. fumigatus nHF-01 produces a potent broad-spectrum AMC 5-butyl-2-pyridine carboxylic acid that could be used against human food and topical pathogenic bacteria. This is the first report of such a compound produced from the A. fumigatus.

Novel-Coronavirus (COVID-19) outburst has become a worldwide pandemic which threaten the scientific community to design and discover efficient and effective treatment strategies against this deadly virus (SARS-CoV-2). Still now, there is no antiviral therapy or drug available in the market which can efficiently combat the infection caused by this virus. In this respect, using available drugs by screening with molecular docking and molecular dynamics studies not only minimizes lengthy chemical trials but also reduces discovery cost for the pharmaceutical industry. During the COVID-19 pandemic situations hydroxychloroquine, chloroquine known as HCQ and CQ tablets have gained popularity as for the treatment coronavirus (COVID-19) but the main threatening effect of HCQ, CQ use lies on their side effects like blistering, peeling, loosening of the skin, blurred vision stomach pain, diarrhea, chest discomfort, pain, or tightness, cough or hoarseness which require immediate medical attention. Encapsulation of HCQ and CQ drugs by the cyclic macromolecules such as α and β-Cyclodextrin, to form host-guest complexes is very effective strategy to mask the cytotoxicity of certain drugs and alleviating and modulating side effects of drug applications. In the present work, we have encapsulated the HCQ and CQ drugs α and β-Cyclodextrin and made a comprehensive analysis of stability, optical properties. Details analysis verified that between QC and HCQ, HQC showed stronger affinity towards β-Cyclodextrin. This strategy can reduce the side effect of HCQ and CQ thereby offers a new way to use these drugs. We hope the present study should help the researchers to develop potential therapeutics against the novel coronavirus.

Energy storage and environmental pollution are two major global concerns in today’s scenario. As a result of the momentous exhaustion of fossil fuels, the generation of energy from renewable sources is gaining immense importance. However, the irregular availability of energy from these renewable sources is the major encounter to achieve sustainable energy harvesting technology, yielding efficient but continuous and reliable energy supplies. Apart from the requirement of state-of-the-art heavy-duty technologies such as transportation, defense, etc., in the modern lifestyle to fulfill the demand for flexible electronic devices, the development of high-performance mechanically flexible all-solid-state supercapacitors is increasing massively. On the other hand, to cater to the need for accessibility of clean water for healthy lives, several technologies are evolving to treat wastewater and groundwater. Hence, the development of efficient catalysts for destroying water pollutants is an attractive approach. Considering these two crucial facets, in this paper, we have demonstrated the multifunctional features of a CuFe2O4-rGO nanocomposite, which was exploited to fabricate a high-performance mechanically flexible all-solid-state asymmetric supercapacitor and simultaneously used as an efficient but easily recoverable catalyst for the transformation of different nitroaromatic compounds. We have also demonstrated the conversion of trifluralin (a herbicide), which is present in the water body as a pollutant, to its corresponding amine derivatives, which can be utilized in the preparation of important pharmaceutical products.

Nanostructured materials have gained immense attraction because of their extraordinary properties compared to the bulk materials to be used in a plethora of applications in myriad fields. In this review article, we have discussed how the Density Functional Theory (DFT) calculation can be used to explain some of the properties of nanomaterials. With some specific examples here, it has been shown that how closely the different properties of nanomaterials (such as optical, optoelectronics, catalytic and magnetic) predicted by DFT calculations match well with the experimentally determined values. Some examples were discussed in detail to inspire the experimental scientists to conduct DFT-based calculations along with the experiments to derive a better understanding of the experimentally obtained results as well as to predict the properties of the nanomaterial. We have pointed out the challenges associated with DFT, and potential future perspectives of this new exciting field.

Graphic abstract Outbreak of Coronavirus (SARS-CoV-2) has thrown a big challenge to the globe by snatching millions of human lives from the world. In this study, inhibitory efficiency of ten anti-HIV compounds from different Indian medicinal plant parts have been virtually screened against Mpro, PLpro and RdRp proteins of SARS-CoV-2. The molecular docking study reflected that among these compounds, Proptine (PTP) has the highest binding affinity for the three cases. Introduction of PTP molecules within the binding pocket of these proteins showed a large structural and conformational changes on the structure of proteins which is revealed from molecular dynamics (MD) simulation studies. RMSD, RMSF and analysis of thermodynamic parameters also revealed that PTP makes a huge impact on the structures of the respective proteins which will pave an opportunity for doing advanced experimental research to evaluate the potential drug to combat COVID-19. Supplementary Information The online version contains supplementary material available at 10.1007/s13721-021-00309-3.

Monochoria hastata (L.) Solms (family Pontederiaceae), an ethnomedicinal aquatic herb, is used to remedy several gastrointestinal diseases by various ethnic groups in India. The present study aimed to purify and characterize the antibacterial active ingredient against gastrointestinal (GI) diseases and its mode of action using in vitro experimental models. The active lead molecule in the ethyl acetate extract (EA-Mh) fraction has been purified and characterized through high-performance liquid chromatography (HPLC), proton nuclear magnetic resonance ((1)H NMR), and electrospray ionization mass spectrometry (ESI–MS) methods. The anti-enteric efficacy has been evaluated against enteropathogenic Gram-positive and Gram-negative bacteria by minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), lactate dehydrogenase (LDH), and scanning electron microscopy (SEM) studies. The synergistic and antagonistic studies were done on E. coli MTCC 723 using standard antibiotics (ampicillin and kanamycin, final conc. 50 µg/ml) in a sterilized 96-well micro-plate, incubated at 37 ℃ for 24 h. The chromatographic and spectroscopic analyses revealed the presence of tridecanoic acid methyl ester (TAME) in the bioactive fraction. The compound causes significant extracellular leakage activity by disrupting cellular morphology in the Enterococcus faecalis MCC 2041 T and Salmonella enterica serovar Typhimurium MTCC 98, at a dose of 375 μg/ml and 750 μg/ml, respectively. The SEM study shows a significant rupturing of E. coli and E. faecalis cells due to TAME induced autolysis. It has synergistic activity with ampicillin. The in silico molecular docking through the AutoDock Vina 4.2 and GROMACS (ver. 5.1) Charmm27 force field results showed that the TAME had a strong binding affinity Escherichia coli DNA Gyrase B (PDB ID: 5l3j.pdb) protein and caused conformational changes. Thus, the manuscript reports the first time on the characterization of TAME from this plant with a detailed antibacterial mode of action studies. GRAPHICAL ABSTRACT: [Image: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s42770-022-00696-3.

Highlights • 19 compounds from Neem extract tested against 7 standard anti-COVID drugs for action on PLpro of latter. • All 19 NEEM molecules show better docking, ADME results vis-a-vis standard drugs. • Among the 19, desacetylgedunin (DCG) gives highest docking score with PLpro. • MD simulation of shows binding with DCG induces large structural change on PLpro., Azadirachta Indica (Neem) extracts have been known for their anti-bacterial and other effects since ancient times. The present work examines the inhibitory activity of Neem extracts on Papain like protease (PLpro) of the novel coronavirus SARS-CoV-2. The activity is analysed by molecular docking study along with molecular dynamics simulation. All the studied Neem compounds showed decent level of inhibitory activity against PLpro of SARS-CoV-2. Among them, desacetylgedunin (DCG) found in Neem seed showed the highest binding affinity towards PLpro. Furthermore, MD-simulation studies supported by standard analysis (e.g. root mean square deviation and fluctuation (RMSD, RMSF), radius of gyration, solvent accessible surface area (SASA)) showed large impact on the structure of PLpro by DCG. We believe that the significant effect of DCG on PLpro may help in therapeutic efforts against SARS-CoV-2., Graphical abstract Image, graphical abstract

Herein we have investigated the ability of the (6,6) MoS

The present work is an investigation to test hydroxychloroquine as an inhibitor for the COVID-19 main protease. Molecular docking studies revealed a high docking score and interaction energies and decent level of docking within the cavity in protease moiety. Molecular dynamics simulations also lead to the evaluation of conformational energies, average H-bonding distance, RMSD plots etc. Large RMSD fluctuations for the first 2 ns seem to provide the conformational and rotational changes associated with the drug molecule when it comes into the vicinity on the protease matrix. Snapshots of structural changes with respect to time vividly indicates that drug molecule has a profound impact on the binding sites as well as overall geometry of the protease moiety. On the whole, hydroxyxhloroquine confers good inhibitory response to COVID-19 main protease. We hope the present study should help workers in the field to develop potential vaccines and therapeutics against the novel coronavirus., Highlights • Molecular Docking studies reveals that hydroxychloroquine (HCQ) possesses a high docking score and interaction energy compared to other small drug molecule with the COVID-19 main protease. • Atomistic Molecular Dynamics simulation indicates considerable interaction between HCQ and COVID-19 protease. • RMSD plot suggests complex formation between HCQ and COVID-19 protease after 2 ns. • Equilibration of binding occurs between HCQ and COVID-19 protease between 7 and 10 ns. • Large structural change occurs in the COVID-19 protease following binding with HCQ between 2 and 7 ns, which may be responsible for change in activity of the former after binding with HCQ.

Electroactive polymeric composites are recent generation material for energy application in lithium batteries, solar cells and supercapacitors. In present study, reduced graphene oxide is prepared from graphite powder using liquid exfoliation. The synthesized reduced graphene oxide is embedded with polystyrene sulfonic acid/lithium phosphate polymer electrolyte to obtain polymer composite films. The dielectric studies of composite reveals huge change in relaxation time with addition of rGO in polymeric lithium ion composites. This attributes to decrease in ion-dipolar interaction strength and enhanced polymer segmental motion in presence of carbon. It also implies the activation of electrochemical properties of polystyrene sulfonic acid/lithium phosphate/reduced graphene oxide (PL–rGO) composites which can be effectively utilize for charge storage applications. The PL–rGO composite exhibits an improved electrochemical performance with different scan rate on potential window ranged between − 0.5 and 1.2 V. The specific capacitance value of ~ 17 F/g with high rate charge–discharge capability over 8000 cycles was observed. Higher electrochemical stability and steady charge/discharge behavior makes PL–rGO composites a promising candidate for charge storage applications.

The present study reports a novel, one-pot, cost-effective, green synthesis route of silver nanoparticles (AgNPs) from the fruit epicarp extract of Glycosmis pentaphylla (FGP). The UV–Vis spectroscopy (UV-Vis), dynamic light scattering (DLS), and transmission electron microscopy (TEM) studies confirmed that the synthesis produces stable, monodispersed AgNPs with an average size of 17 nm. Fourier transform infrared spectroscopy (FTIR) studies suggested that the carbonyl group of the different compounds of FGP made significant interaction with AgNPs. With this indication, a theoretical simulation using density functional theory (DFT) was performed, which established that among the different compounds of FGP, arborine was mainly responsible for the stabilization of AgNPs with a binding energy of 58.45 kJ/mol. Synthesized AgNPs showed strong antifungal (against Alternaria alternata, Colletotrichum lindemuthianum, Fusarium moniliforme, and Candida glabrata) and antibacterial (against Bacillus subtilis, Streptococcus mutans, Escherichia coli, and Salmonella enterica serovar Typhimurium) activity. Synthesized AgNPs showed the highest antifungal activity against Fusarium moniliforme and the highest antibacterial activity against Salmonella enterica serovar Typhimurium. A remarkable synergistic activity of AgNPs was observed with fungicide Bavistin (∼25% increased activity against Alternaria alternata) and antibiotic Streptomycin (∼33.3% increased activity against Bacillus subtilis), which indicated that AgNPs could be applied to control crop and human pathogens with a lower dose of synthetic antimicrobial compounds (e.g., Bavistin, Streptomycin, etc.). Hence, green synthesized AgNPs by this method can be a blessing for crop productivity and hospital management as an effective alternative to conventional fungicides and antibiotics, respectively.

Here, we report a simple ‘in situ’ co-precipitation reduction synthesis method for the preparation of nanocatalysts composed of Ag, Ni nanoparticles, and reduced graphene oxide (RGO). First-principles calculations based on Density Functional Theory (DFT) were performed to obtain the electronic structures and properties of Ag–Ni-graphene superlattice and to understand the interfacial interactions which exist at the interface between Ag, Ni, and graphene. The catalytic performance of the synthesized catalysts (AgxNi(1−x))yRGO(100−y) were evaluated for four reactions (i) reduction of 4-nitrophenol (4-NP) in the presence of excess NaBH4 in aqueous medium, (ii) A3 coupling reaction for the synthesis of propargylamines, (iii) epoxidation of styrene, and (iv) ‘Click reaction’ for the synthesis of 1,2,3-triazole derivatives. For all of these reactions the catalyst composed of Ag, Ni, and RGO, exhibited significantly higher catalytic activity than that of pure Ag, Ni, and RGO. Moreover, an easy magnetic recovery of this catalyst from the reaction mixture after completion of the catalytic reactions and the good reusability of the recovered catalyst is also reported here. To the best of our knowledge, this is the first time the demonstration of the versatile catalytic activity of (AgxNi(1−x))yRGO(100−y) towards multiple reactions, and the DFT study of its electronic structure have been reported.

Here, we report an ‘in situ’ co-precipitation reduction based synthetic methodology to prepare CuFe2O4 nanoparticle–reduced graphene oxide (CuFe2O4–RGO) nanocomposites. First principles calculations based on Density Functional Theory (DFT) were performed to obtain the electronic structures and properties of CuFe2O4, graphene and CuFe2O4–graphene composites, and to understand the interfacial interaction between CuFe2O4 and graphene in the composite. The synergistic effect, which resulted from the combination of the unique properties of RGO and CuFe2O4 nanoparticles, was exploited to design a magnetically separable catalyst and high performance supercapacitor. It has been demonstrated that the incorporation of RGO in the composite enhanced its catalytic properties as well as supercapacitance performance compared with pure CuFe2O4. The nanocomposite with 96 wt% CuFe2O4 and 4 wt% RGO (96CuFe2O4–4RGO) exhibited high catalytic efficiency towards (i) reduction of 4-nitrophenol to 4-aminophenol, and (ii) epoxidation of styrene to styrene oxide. For both of these reactions, the catalytic efficiency of 96CuFe2O4–4RGO was significantly higher than that of pure CuFe2O4. The easy magnetic separation of 96CuFe2O4–4RGO from the reaction mixture and good reusability of the recovered catalyst also showed here. 96CuFe2O4–4RGO also demonstrated better supercapacitance performance than pure CuFe2O4. 96CuFe2O4–4RGO showed specific capacitance of 797 F g−1 at a current density of 2 A g−1, along with ∼92% retention for up to 2000 cycles. To the best of our knowledge, this is the first investigation on the catalytic properties of CuFe2O4–RGO towards the reduction of 4-nitrophenol and the epoxidation reaction, and DFT calculations on the CuFe2O4–graphene composite have been reported.

Herein we have made a comprehensive analysis of the mode of interactions between the L-Alanine/L-Valine and Chloroquine diphosphate in aqueous solution. Evaluation of different Physico-chemical parameters like density, viscosity, refractive index, conductance study (at three different temperatures), and surface tension (at 298.15 K) at atmospheric pressure have used to help in the gathering of knowledge about the existence of plausible intermolecular interactions in the ternary (Drug + Water + Amino acid) solution. Furthermore, apparent molar volume, limiting apparent molar volume, viscosity B-coefficient, and molar refraction, limiting molar refraction all support the idea that the leading solute–solvent interaction is influenced by the solute concentration and temperature. In addition, in aqueous Chloroquine diphosphate, both amino acids showed structure-breaking activities. The system's Gibbs free energy change was measured, suggesting its spontaneity. The 1H NMR spectroscopy results showed significance changes in the shifting of aromatic protons of CDP and protons of amino acids indicating that a strong interaction (hydrophobic-hydrophobic) takes place among them which is further supported by our theoretical observations. L-Valine-Drug interactions were found to be more predominating over L-Alanine-Drug interactions, according to both experiment and theory. Models for mixtures of drug molecules and amino acids could be developed using the experimental and correlated results.

In this work, an optimum sodium alginate (NaAlg)-grafted-[sodium 2-methylenesuccinate-co-sodium 2-((2-(isobutyryloxy)ethoxy)methyl)succinate-co-ethylene glycol methacrylate, i.e., SMS-co-SIBEMS-co-EGMA, i.e., P1], i.e., P2, was selected among twelve hydrogels synthesized by employing variable amounts of synthesis parameters through a facile polymerization of SMS and EGMA monomers. In P1 and P2, SIBEMS third comonomer was strategically anchored in situ. The formation of terpolymer, i.e., P1, rather than generally expected copolymer, i.e., SMS-co-EGMA/ CoP1, was explored via closeness of experimental and simulated excitation energies of P1 and CoP1, measured by using density functional theory (DFT). The grafting of NaAlg into synthetic P1 elevated swelling, crosslink density (CD), network stability, reusability, and adsorption capacity (AC) of semisynthetic hydrogel, i.e., P2. The reusable P2 presenting optimum result among swelling, CD, and mean molar mass was chosen selectively for removals of As(III) and V(V). The structures of P1, P2, and adsorbed P2, i.e., As(III)-P2 and V(V)-P2; NaAlg-grafting; in situ anchored SIBEMS comonomer; reusability; thermostability; and surface properties were explored through XPS-NMR-FTIR-UV-vis, DFT, TG, DLS, XRD, SEM, pHPZC, and network and thermodynamic energies. The ACs of 0.025 g P2 for As(III) and V(V) were 112.24 and 88.89 mg g−1, respectively, at 308 K and within 5–100 mg L−1. The ACs reduced to 67.26, 75.49, 71.42, and 98.25 mg g−1 for As(III) and 40.25, 50.49, 45.37, and 67.88 mg g−1 for V(V) in the presence of Mn(II), Cu(II), Ni(II), and Zn(II), respectively.