One Precursor, Two Different Outcomes: SnO-Graphite Composite and Anion-Doped SnO2 with Ester Surface Functionality.

The technological importance of SnO2 and SnO has invited scientists to explore various aspects, including their synthesis in the nanosize regime, surface functionalization, and composite formation. In the present work, a binuclear Sn2-EDTA complex has been demonstrated to produce a SnO-graphite composite and C, N-codoped SnO2 nanocrystals with ester functionality in quantitative yields by thermal and solvothermal dissociation processes. The products were characterized extensively. While SnO in the SnO-graphite composite exhibited tetragonal symmetry, graphitic carbon had defects. The composite had 12 wt % of graphitic carbon. The role of the SnO-graphite composite as an anode in lithium-ion batteries (LIB) has been evaluated. Solvothermal dissociation of the Sn2-EDTA complex in a propylene glycol medium yielded nanocrystalline SnO2 with yellow color. Agglomerated crystallites had ester functionality on their surfaces. The surface functionality was thermally stable up to 200 °C, and its complete removal yielded tetragonal white-colored SnO2. Co-doping of carbon and nitrogen in yellow SnO2 reduced its optical band gap (2.9 eV). Despite the negative surface charge of the functionalized SnO2, its affinity to rapidly adsorb anionic azo dyes (Congo red and Eriochrome black T) from aqueous solutions has been validated. Following pseudo-second-order kinetics, adsorption data analysis revealed chemisorption as the primary driving force in this process.

Hole and Electron Doping Outcomes in Bi2YO4Cl.

Recognizing the deficiency in the hole and electron doping outcomes in layered bismuth-based oxyhalides intergrowths, the current study was addressed to the doping of Ca2+ and Zr4+ for Y3+ in Bi2YO4Cl. The samples were rapidly synthesized by a sol-gel auto combustion method and characterized extensively. Up to 30 mol % Y could be substituted with Ca in tetragonal symmetry and without the appearance of any additional phase. The unit cell parameters varied nonlinearly with the elongation of the Y-O bond. The Raman spectra supported the local site distortion. The calcium-substituted samples displayed selected area electron diffraction characteristics similar to those of Bi2YO4Cl. A blueshift of the absorption edge was noticed with increasing calcium content yielding optical band gap values in the 2.40-2.57 eV range. The creation of 10% Bi5+ in Bi2Y0.70Ca0.30O4Cl was established with the help of XPS measurements and redox titrations. The higher reactivity of Bi5+ in an aqueous solution has been demonstrated for the oxidation of As(III) to As(V). Electron doping through Zr4+ incorporation was possible up to 30 mol % in Bi2YO4Cl. The Y-O bonds are contracted, and the Bi-O bonds are elongated with increasing Zr4+ content. Zr4+'s incorporation induced a local distortion. The color of the sample changed from bright yellow to deep yellow with Zr inclusion, resulting in a progressive decrease in optical band gap values. The introduction of electrons caused the reduction of 13.6% of Bi(III) to Bi(0). These results have established the vulnerability of Bi2O2 chains to charge carriers in Bi2YO4Cl. Density functional theory (DFT) calculations were implemented to understand the electronic and optical properties of the pristine and doped compounds. From the band structure calculations, the chosen compounds were found to be indirect band gap semiconductors. The results of the DFT calculations were in good agreement with the experiment; however, for the doped cases, virtual crystal approximation has been used considering uniform doping at the Y-site.

Zircon PrVO4: an efficient heterogeneous catalyst for tandem oxidative synthesis of 2,3-disubstituted quinoline derivatives.

The current study addresses the usage of inherent redox couplets in PrVO4 crystallizing in a zircon-type structure for tandem oxidative transformation. Monophasic PrVO4, synthesized using a solution combustion synthesis method, showed a tetragonal zircon-type structure in its PXRD pattern (S.G. I41/amd). The tetragonal symmetry of the zircon PrVO4 was also confirmed from electron microscopic and vibrational spectroscopic measurements. From XPS analysis, the existence of redox couplets Pr3+/Pr4+ and V4+/V5+ in PrVO4 was established. The catalytic utility of zircon PrVO4 for one-pot synthesis of 2,3-disubstituted quinolines through the oxidative tandem reaction of 2-aminobenzylalcohols with 1,3-dicarbonyl compounds has been demonstrated. This highly efficient method proceeds under molecular oxygen, tolerates different functional groups, and produces various substituted quinoline derivatives in good to excellent yields. The important features of the process are the easy workup, simple catalyst recovery, and reusability.

Magnetically recoverable Fe3O4 nanocatalyst for the synthesis of biodynamically significant 1H-pyrazolo[1,2-b]phthalazine-5,10-diones derivatives and its DFT study.

An environmentally sustainable and proficient method is reported for the synthesis of medicinally important pyrazolo[1,2-b] phthalazine dione derivatives by aqueous micellar medium catalysed by Fe3O4 NPs. Dialkyl acetylenedicarboxylate with isocyanides in the presence of phthalhydrazide is used as starting material. The main advantages of this protocol are the availability of starting materials, short reaction times, green solvents and practical simplicity.

Designing Self-Inhibitory fusion peptide analogous to viral spike protein against novel severe acute respiratory syndrome (SARS-CoV-2).

COVID-19 is a highly contagious viral infection caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is declared pandemic by the World Health Organization (WHO). The spike protein of SARS-CoV-2 is a key component playing a pivotal role in facilitating viral fusion as well as release of genome into the host cell. Till date there is no clinically approved vaccine or drug available against Covid-19. We designed four hydrophobic inhibitory peptides (ITPs) based on WWIHS (Wimley and White interfacial hydrophobicity scale) score, targeting the HR1 domain of spike protein. Two inhibitory peptides out of four have a strong affinity to the hydrophobic surface of HR1 domain in pre-fusion spike protein. The MD simulation result showed the strong accommodation of ITPs with HR1 domain surface. These self-inhibitory peptides mimic the function of HR2 by binding to HR1 domain, thus inhibiting the formation of HR1-HR2 post-fusion complex, which is a key structure for virus-host tropism.Communicated by Ramaswamy H. Sarma.

BF3-etherate promoted facile access to vinyloxyimidazopyridines: a metal-free sustainable approach.

A convenient and metal-free synthesis of vinyloxyimidazopyridine derivatives has been attained via BF3.OEt2 promoted one-pot multicomponent approach. This procedure involves a facile coupling of 2-aminopyridine derivatives with arylglyoxal and alkyne derivatives. BF3.OEt2 complexation has successfully catalyzed the reaction at room temperature. Utilization of transition metal-free catalyst, mild reaction conditions, easy handling and operational simplicity are key features of developed process.

Finding potent inhibitors for COVID-19 main protease (Mpro): an in silico approach using SARS-CoV-3CL protease inhibitors for combating CORONA.

SARS-CoV-2 is liable for the worldwide coronavirus disease (COVID-19) exigency. This pandemic created the need for all viable treatment strategies available in the market. In this scenario, computer-aided drug design techniques can be efficiently applied for the quick identification of promising drug repurposing candidates. In the current study, we applied the molecular docking approach in conjugation with molecular dynamics (MD) simulations to find out potential inhibitors against Mpro of SARS-CoV-2 from previously reported SARS-3CL protease inhibitors. Our results showed that N-substituted isatin derivatives and pyrazolone compounds could be used as a potent inhibitor and may possess an anti-viral activity against SARS-CoV-2. However, further experimental investigation and validation of the selected hits are required to find out their suitability for clinical trials. Communicated by Ramaswamy H. Sarma.

Canalicular adenoma of the tongue: report of a unique case.

Canalicular adenoma (CA) is a rare, unique benign salivary gland neoplasm, which usually involves the minor salivary glands of the upper lip, buccal mucosa and palate. It is usually seen in middle-aged or older individuals, has a female predilection, and commonly presents as a painless, slow-growing, non-ulcerated nodule or swelling. Its treatment involves surgical excision or enucleation. This case report describes a case of CA of the ventrum of the tongue diagnosed in a 41-year-old male patient, which could possibly be the first reported case of this lesion involving the tongue.

Molecular dynamics simulations and experimental studies reveal differential permeability of withaferin-A and withanone across the model cell membrane.

Poor bioavailability due to the inability to cross the cell membrane is one of the major reasons for the failure of a drug in clinical trials. We have used molecular dynamics simulations to predict the membrane permeability of natural drugs-withanolides (withaferin-A and withanone) that have similar structures but remarkably differ in their cytotoxicity. We found that whereas withaferin-A, could proficiently transverse through the model membrane, withanone showed weak permeability. The free energy profiles for the interaction of withanolides with the model bilayer membrane revealed that whereas the polar head group of the membrane caused high resistance for the passage of withanone, the interior of the membrane behaves similarly for both withanolides. The solvation analysis further revealed that the high solvation of terminal O5 oxygen of withaferin-A was the major driving force for its high permeability; it interacted with the phosphate group of the membrane that led to its smooth passage across the bilayer. The computational predictions were tested by raising and recruiting unique antibodies that react to withaferin-A and withanone. The time-lapsed analyses of control and treated cells demonstrated higher permeation of withaferin-A as compared to withanone. The concurrence between the computation and experimental results thus re-emphasised the use of computational methods for predicting permeability and hence bioavailability of natural drug compounds in the drug development process.

Metal-free visible-light-mediated organophotoredox catalysis: synthesis of 3-functionalized indole via C-C, C-N bond formation.

A visible-light-mediated, mild and one-pot three-component reaction in the presence of organophotoredox catalyst Eosin Y using EtOH:H2O as reaction medium for the synthesis of 3-functionalized indole derivatives was developed. Visible light used in the protocol is green, inexpensive, readily available energy source. The sustainable reagents make the protocol compatible with green chemistry demands.

Identification of Drug Candidates for Breast Cancer Therapy Through Scaffold Repurposing: A Brief Review.

Conventional drug discovery is a time consuming and expensive expedition with less clinical preference achievement proportion intended for breast cancer therapy. Even if numerous novel approaches to the conformation of drugs have been introduced for breast cancer therapy, they are yet to be implemented in clinical practice. This tempting strategy facilitates a remarkable chance to take the entire benefit of existing drugs. Despite drug repurposing significantly decrease the investigational period and cost, it has got many objections and issues. Scaffold repurposing is an approach that procures a novel significance on the decrepit motto of "to commencement with a pristine drug" . Hence, we move into a probable and nearer approach, the exploitation of scaffolds, which was originally developed for other purposes, including anti-tumor activity. In this review, we summarize different drugs and scaffolds used in breast cancer therapy.

Withdrawal Notice: Design and Synthesis of a Novel Gabapentin- Phosphotidylcholine Conjugate for Targeting to Phospholipase A2 Enzyme through Nanostructured Lipid Carrier

The article for the journal Current Computer-Aided Drug Design has been removed by the Publisher due to acute language inconsistencies and grammatical errors. Bentham Science apologizes to the readers of the journal for any inconvenience this may cause. The Bentham Editorial Policy on Article Withdrawal can be found at https://benthamscience.com/editorialpoliciesmain.php BENTHAM SCIENCE DISCLAIMER: It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere. Furthermore, any data, illustration, structure or table that has been published elsewhere must be reported, and copyright permission for reproduction must be obtained. Plagiarism is strictly forbidden, and by submitting the article for publication the authors agree that the publishers have the legal right to take appropriate action against the authors, if plagiarism or fabricated information is discovered. By submitting a manuscript, the authors agree that the copyright of their article is transferred to the publishers if and when the article is accepted for publication.

Systematic approach of chromone skeleton for detecting Mg2+, ion: Applications for sustainable cytotoxicity and cell imaging possibilities.

The systematic studies of chromone appended novel chemosensors, favored to Mg2+ ion detection, these were analyzed and characterized by different spectroscopic techniques such as NMR, mass spectroscopy, FTIR and optical techniques. The binding demeanor of the ligands was executed with the library of metal ions and shown the good coordination with Mg2+ ion to the ligand's cavity. Both ligands demonstrated good binding behavior with Mg2+ ion. The ligands represented 1: 1 stoichiometry with Mg2+ ions through Job's plot. The low limit of detection of Mg2+ ion was determined as 2.56 × 10-6 and 1.28 × 10-6 for La and Lb respectively. No interference was occurred in Inference study by foreign metal ions that supported the specific detection of Mg2+ ion among the other metal ions. Further, the cytotoxicity assay test of these chromone appended ligands revealed that both ligands and their respective compound with Mg2+ ion shown negligible toxicity with HeLa cancer cell line. Further, due to the fluorescence properties of the ligands, with or without Mg2+ ion was successfully tested in bioimaging experiment of HeLa cancer cell lines and found that ligands with Mg2+ ions represented good imaging with HeLa cancer cell.

A New Class of Coumate Benzimidazole Hybrids as BRCA 1 Mimetics Through Unconventional Binding Mode; Synthesis and Preliminary Cytotoxicity Screening.

BACKGROUND: It was found that breast cancer susceptibility protein 1 (BRCA 1) binds to estrogen receptor alpha (ERα) and inhibits its activity by direct interaction between domains within the amino terminus of BRCA 1 and the carboxy terminus of ER alpha. OBJECTIVES: The present work focuses to identify a new class of BRCA 1 mimetics that work differently from conventional anti-estrogens. METHODS: A novel class of hybrids having coumate and benzimidazolone scaffolds were designed to mimic BRCA 1 protein, suppressing the tumor activity of breast cancer cells. In silico molecular docking studies of the designed ligands were performed on BRCA 1 binding cavity of ER alpha. RESULTS: The designed hybrids which gave significant docking scores and had optimum binding interactions with key residues were selected for synthesis and in vitro assay. CONCLUSION: The compounds NY1 and NY2 exhibited significant effects on suppressing MDAMB- 231 cells in the concentration of 24 µg/ml and 44 µg/ml, respectively.

Conformational perturbation of peptides in presence of polar organic solvents.

The critical role played by solvent environment in maintaining the conformational integrity of peptides and proteins is accepted without question. Numerous experiments have suggested that perturbing the solvent environment of peptides and proteins by the addition of polar organic solvents have important consequences for the conformation of these molecules. However, experimental studies of such perturbations often report different kinds of effects depending on the solvent used and/or the sequence/structure of the molecule under study. In this work we report a simulation based comparative study on the effects of adding two common organic solvents viz. Dimethyl sulfoxide (DMSO) and Acetonitrile (MeCN) on the dynamical conformation of a test peptide Ace-Gly-X-Gly-Nme where X is any amino acid. Our studies identify important differences in peptide solvation by these two solvents, which we attempt to correlate with the kinetic stability of the conformation, as well as the identity of the central 'X' residue in the test peptide.

Role of Ser65, His148 and Thr203 in the Organic Solvent-dependent Spectral Shift in Green Fluorescent Protein.

The photophysics of green fluorescent protein (GFP) is remarkable because of its exceptional property of excited state proton transfer (ESPT) and the presence of a functional proton wire. Another interesting property of wild-type GFP is that its absorption and fluorescence excitation spectra are sensitive to the presence of polar organic solvents even at very low concentrations. Here, we use a combination of methodologies including site-specific mutagenesis, absorption spectroscopy, steady-state and time-resolved fluorescence measurements and all-atom molecular dynamics simulations in explicit solvent, to uncover the mechanism behind the unique spectral sensitivity of GFP toward organic solvents. Based on the evidences provided herein, we suggest that organic solvent-induced changes in the proton wire prevent ground state movement of a proton through the wire and thus bring about the spectral changes observed. The present study can not only help to understand the mechanism of proton transfer by further dissecting the intricate steps in GFP photophysics but also encourages to develop GFP-based organic solvent biosensors.

A statistical geometry analysis of simulated water-DMSO and water-MeCN binary mixtures for biomolecular studies.

Water-Dimethylsulfoxide (DMSO) and water-Acetonitrile (MeCN) binary mixtures at various molar ratios ranging from 0 to 1 are studied using Molecular Dynamics (MD) simulations. Hydration properties of water in different regions of MeCN/DMSO are investigated by using the statistical geometry approach. The obtained results reveal that in water-DMSO simulations both water and solvent molecules prefer to be in mixed cluster forms, depending upon the concentration of DMSO. While in case of water-MeCN mixtures, self-association of water and acetonitrile molecules, take place, showing microheterogeneity associated with the water- MeCN binary mixtures. The results highlight the utility of statistical geometric analysis of MD simulation data of binary liquid mixtures for rapid screening of polar organic solvents in non-aqueous enzymology.

A turn-on ESIPT based fluorescent sensor for detection of aluminum ion with bacterial cell imaging and logic gate applications.

6-amino-5-(((2-hydroxynaphthalen-1-yl)methylene)amino)-2-mercaptopyrimidin-4-ol (L1) and 6-amino-5-((4-bromobenzylidene)amino)-2-mercaptopyrimidin-4-ol (L2) have been designed and characterized by various techniques such as UV-Vis, fluorescence, FT-IR, mass spectrometry and NMR spectroscopy. L1 was successfully applied for selective recognition of aluminum ion and showed "OFF-ON type" mode in the presence of Al3+ ion. The sensor was recommended for the selective detection of Al3+ with 1:1 stoichiometry by Job's plot in ACN medium. The high sensitivity of host L1 supports the high detection limit, 99 nM with good association constant. It was also used for bacterial cell imaging (E.coli DHα) and logic gate applications which was manifested the green and red fluorescent images with Al3+ion and represents INHIBIT logic gate in switching behavior.