Breaking the exascale barrier for the electronic structure problem in ab-initio molecular dynamics

The non-orthogonal local submatrix method applied to electronic structure–based molecular dynamics simulations is shown to exceed 1.1 EFLOP/s in FP16/FP32-mixed floating-point arithmetic when using 4400 NVIDIA A100 GPUs of the Perlmutter system. This is enabled by a modification of the original method that pushes the sustained fraction of the peak performance to about 80%. Example calculations are performed for SARS-CoV-2 spike proteins with up to 83 million atoms. [ FROM AUTHOR] Copyright of International Journal of High Performance Computing Applications is the property of Sage Publications, Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Naphtho[2,1-b]furan derived triazole-pyrimidines as highly potential InhA and Cytochrome c peroxidase inhibitors: Synthesis, DFT calculations, drug-likeness profile, molecular docking and dynamic studies

Napthofuran and its fused heterocyclic derivatives evaluated with varied biological activity functional groups comprise an important class of compounds for new chemical entities. We here in reporting synthesis of new 3-(4-substituted phenyl)naphtho[1′,2′:4,5]furo[2,3-e][1,2,4]triazolo[4,3-c]pyrimidines 6(a-f). Structures of the newly synthesized compounds were confirmed by making use of spectroscopic techniques like IR, NMR and Mass. The DFT calculations were taken for the selected molecules using B3LYP hybrid functional with a 6–31+G (d, p) all-electron basis set using the Gaussian 09 package. The bioactivity predictions were evaluated for the synthesized compounds. The In vitro biological activities were reported for the all compounds 6(a-f). The compound 6a showed high activity of anti-TB and antioxidant activity with at MIC 1.6 μg/ml and at percentage of inhibition (72.54±0.21) at 10μg/ml respectively. The compound 6f (73.21±0.11) showed antioxidant activity better than standard drug BHA (71.32±0.13) at 10 μg/ml. Furthermore, the docking studies for the newly synthesized molecules were carried out by Auto dock software with proteins InhA (4TZK),Cytochrome c peroxidase (2 × 08) and protease (Mpro) of SARS-CoV-2 Omicron (PDB ID: 7TOB). All the compounds showed a strong binding affinity for the docked proteins. The outcome of docking results showed that compound 6ahad excellent binding energies -10.8, -9.4, and -9.0 kcal/mol with 4TZK, 2 × 08, and 7TOB respectively. Lastly, the protein stability, fluctuations of APO-Protein, protein-ligand complexes were investigated through Molecular Dynamics (MD) simulations studies using Desmond Maestro 11.3 and potential lead molecules were identified. © 2023

Structural and Computational Studies of Cobalt(II) and Copper(II) Complexes with Aromatic Heterocyclic Ligand

Two coordination complexes, a cobalt(II) complex tris(1,10-phenanthroline)-cobalt perchlorate hydrate, [Co(phen)3]·(ClO4)2·H2O(1), and a copper(II) complex tris(1,10-phenanthroline)-copper perchlorate 4-bromo-2-{[(naphthalene-1-yl)imino]methyl}phenol hydrate, [Cu(phen)3]·(ClO4)2·HL·[O] (2), [where, phen = 1,10-phenathroline as aromatic heterocyclic ligand, HL = 4-bromo-2-((Z)-(naphthalene-4-ylimino) methyl) phenol] have been synthesized and structurally characterized. Single crystal X-ray analysis of both complexes has revealed the presence of a distorted octahedral geometry around cobalt(II) and copper(II) ions. density functional theory (DFT)-based quantum chemical calculations were performed on the cationic complex [Co(phen)3]2+ and copper(II) complex [Cu(phen)3]2+ to get the structure property relationship. Hirshfeld surface and 2-D fingerprint plots have been explored in the crystal structure of both the metal complexes. To find potential SARS-CoV-2 drug candidates, both the complexes were subjected to molecular docking calculations with SARS-CoV-2 virus (PDB ID: 7BQY and 7C2Q). We have found stable docked structures where docked metal chelates could readily bound to the SARS-CoV-2 Mpro. The molecular docking calculations of the complex (1) into the 7C2Q-main protease of SARS-CoV-2 virus revealed the binding energy of −9.4 kcal/mol with a good inhibition constant of 1.834 µM, while complex (2) exhibited the binding energy of −9.0 kcal/mol, and the inhibition constant of 1.365 µM at the inhibition binding site of receptor protein. Overall, our in silico studies explored the potential role of cobalt(II) complex (1), and copper(II) complex (2) complex as the viable and alternative therapeutic solution for SARS-CoV-2.

Pterin interactions with gold clusters: A theoretical study

Gold (Au) nanoclusters (NCs) are novel materials with low cytotoxicity and high chemical stability. These properties are in high demand during the bioimaging. Moreover, the optical properties of gold clusters allow to use them as colorimetric and luminescent bionanosensors. Pterins are low molecular weight organic compounds, which are used in medicine as biomarkers of phenylketonuria, vitiligo, inflammation and immune system activation, cancer, COVID-19, etc. We have investigated the possibility of gold nanosensors usage to detect pterin (Ptr). Ptr-Aunq structures (n = 1–6;q = 0–2) Gibbs energy of complexation (Eb) have been obtained using density functional theory. The highest Eb was determined for the complexes of Au62+ and Au32+ in acidic and alkaline aqueous solution, respectively. The detection of pterin with gold clusters seems to be prospective using both colorimetric and fluorescent detection because of the intense S0→S1 transition in the absorption spectrum of the Au5+ complex. Raman detection of pterin should be performed at alkaline pH because of the dramatic changes in the spectrum of Ptr−1 upon the addition of Au clusters. We believe that these tunable changes of the pterin spectra due to Au clusters and nanoparticles attachment could be exploited in further studies on nanosensor design. © 2023

Coating of favipiravir (FVP) on silver nanoparticles: First principle study

Silver nanoparticles, thanks to their antiviral and antibacterial properties, have great potential in a variety of applications, such as drug-delivery carriers. The coating properties of silver nanoparticles (size range of 1.6 nm) with a well-known drug, Favipirair, were investigated in this study using quantum mechanical and classical atomistic molecular dynamics simulation in order to use as the drug delivery to treat COVID-19 disease. The drug molecule's optimized structure, frequencies, charge distribution, and electrostatic potential maps were simulated using density functional theory (DFT) at the B3LYP/6–311++g(d,p) level of theory. The coating of AgNP with each of these drugs was then studied using molecular dynamics simulation. The interaction affinity obtained from MD results agrees with the DFT results on drug adsorption on the Ag(1 1 1) slab. © 2023

Computational Investigations for Identification of Bioactive Molecules from Baccaurea ramiflora and Bergenia ciliata as Inhibitors of SARS-CoV-2 Mpro

In this study, a hybrid compound library of 72 phytocompounds from two antiviral medicinal plants (Baccaurea ramiflora and Bergenia ciliata) was computationally investigated for their inhibitory potential against SARS-CoV-2 Mpro. Molecular docking showed that 6-O-vanilloylicariside B5, 6-O-vanilloylisotachioside, leucoanthocyanidin 4-(2-galloyl), and p-hydroxybenzoyl bergenin has good binding affinity for Mpro. However, p-hydroxybenzoyl bergenin did not bind at the catalytic cavity. The RMSD and RMSF data obtained from 100 ns MD simulations revealed stable protein–ligand complexes for 6-O-vanilloylicariside B5, 6-O-vanilloylisotachioside, leucoanthocyanidin 4-(2-galloyl). Ligand trajectory study found 6-O-vanilloylisotachioside and leucoanthocyanidin 4-(2-galloyl) to be stable. Studies on ligand interaction profile and timeline interaction profile showed that 6-O-vanilloylisotachioside and leucoanthocyanidin 4-(2-galloyl) interacted with HIS41–CYS145 dyad and other crucial amino acids of the catalytic site cavity during the entire 100 ns MD simulations. Molecular mechanics generalized born solvent accessibility binding free energy calculations, density functional theory analysis, quantitative structure–property relationship studies, and ADMET profiling of 6-O-vanilloylisotachioside and leucoanthocyanidin 4-(2-galloyl) supported the results generated by molecular docking and MD simulations studies. Based on the current computational investigations, we conclude that that 6-O-vanilloylisotachioside of B. ramiflora and leucoanthocyanidin 4-(2-galloyl) of B. ciliata are two potential inhibitors of SARS-CoV-2 Mpro that are worthy of further investigations.

In silico investigation of metalophthalocyanine substituted in carbon nanocones (TM-PhCCNC, TM= Sc2+, Cr2+, Fe2+and Zn2+) as a promising sensor for detecting N2O gas involved in Covid-19

• Meaningful relationship between N 2 O emissions and cumulative covid-19 was observed. • Sc-phthalocyanine nanocones are fast response and hybrid N 2 O sensor. • Sc-phthalocyanine nanocones record promising values of recovery times for different attempt frequencies. • The N 2 O gas adsorption has a noticeable effect on μ, ω, η, and S values of porphyrin nanoring. • Physisorption of N 2 O Sc-phthalocyanine nanocones change band gap. • Cr- and Zn- phthalocyanine nanocones have the strongest and the weakest E ads of the N 2 O gas, respectively. The structural properties, electronic properties, and adsorption abilities of carbon nanocones doped with metallophthalocyanines (TM-PhCCNC, TM= Sc2+, Cr2+, Fe2+ and Zn2+) over nitrous oxide (N 2 O) molecule were investigated using the density functional theory method (DFT). The binding energies of TM-PhCCNC revealed that the Sc2+, Cr2+, Fe2+ and Zn2+ ions have a strong binding ability with PhCCNC. By calculating the adsorption energies of the N 2 O molecule on the surface of the TM-PhCCNC, the most stable positions and the equilibrium distance are obtained, and the charge transferred and electronic properties have been calculated. The results showed that the N 2 O molecule weakly interacts with Sc2+, Fe2+ and Zn2+-PhCCNC whereas strong adsorption occurred on Cr2+-PhCCNC. The high adsorption potential of TM-PhCCNC is due to the geometrical deformation of the TM doping site and the charge transfer between TM-PhCCNC and the N 2 O molecule. Moreover, a significant increase in the energy gap of the Sc2+-PhCCNC after adsorption of the N 2 O molecule is expected to be an available strategy for improving its electrical conductivity. The results revealed that Sc2+-PhCCNC may be a promising candidate for potential novel sensors for detecting the presence of N 2 O molecules. [Display omitted] [ FROM AUTHOR] Copyright of Journal of Molecular Structure is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Investigate the designing of eutectic mixture using DFT computation and evaluate their biological potency using molecular docking

Researchers are exploring the eutectic mixture because of their obvious great potential in various disciplines. Herein, authors have presented the DFT calculations, molecular docking and QSAR results for designed eutectic mixtures (EMs) using thiourea and resorcinol on taking different equivalent ratio. Authors have used Jakob et al. method to determine the melting temperature of the systems or EMs theoretically. Thermodynamic parameteres such as the free energy, enthalpy, and other energy of the EMs at room temperature are determined through DFT calculations using Gaussian. Authors have also calculated the physiochemical descriptors of various eutectic mixture based on DFT calculations. Further, molecular docking of the designed EMs is carried out to investigate their biological potential for inhibition of the Mpro of SARS-CoV-2. © 2023 Elsevier B.V.

Comparative Study of Molecular Docking, Structural, Electronic, and Fukui Function Studies on Favipiravir and its Newly Designed Derivatives (Potential Inhibitors) for COVID-19 Protease

Favipiravir is an antiviral medication currently being trialed as a COVID-19 treatment. These results motivate us to develop new species (possibly drugs) from favipiravir, perform comparative molecular docking, and reexamine their biological and pharmacological activities. Detailed quantum chemical research on favipiravir and its newly designed derivatives has been carried out with the help of DFT/B3LYP/6–311 + + G (d, p). In the present work, the structure of favipiravir has been modified and 12 new species have been modeled (all species are inherently stable because no virtual frequency is found during the vibration analysis). Reactivity of all species using various descriptors (local) such as Fukui function, local softness, electrophilicity, and global, i.e., electronegativity, hardness, HOMO–LUMO gap, etc. of the same are calculated and discussed. In silico studies such as molecular docking of all species and complete quantum chemistry studies suggest that four of them may mitigate the effects of the COVID-19 protease. © 2023 Wiley-VCH GmbH.

Complex of Ceftriaxone with Mg(II): Synthesis, Structure, Spectral and Antibacterial Properties

Аннотация. Получен и охарактеризован магниевый комплекс цефтриаксона методами атомно-эмиссионного и элементного анализов, ТГА, ИК- и КР-спектроскопии, РФА и расчетов теории функционала плотности. Цефтриаксон координируется к иону магния через кислород триазинового цикла в шестом положении, азот аминогруппы тиазольного цикла и атомы кислорода карбоксильной и лактамной групп. Динатриевая соль цефтриаксона и комплекс магния были исследованы на антибактериальную активность в отношении Staphylococcus aureus, Escherichia coli и Pseudomonas aeruginosa.Alternate abstract:Magnesium complex of ceftriaxone was obtained and characterized by atomic-emission and elemental analysis, TGA, FTIR and Raman spectroscopy, X-ray diffraction and density functional theory calculations. Ceftriaxone was coordinated to the magnesium ion by the oxygen of the triazine cycle in the 6th position, the nitrogen of the amine group of the thiazole ring, and oxygen atoms of the lactam carbonyl and carboxylate groups. The disodium salt of ceftriaxone and magnesium complex were screened for antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa.

Graphene Versus Coronavirus: A Study of the Graphene Properties that Can Help Combat Coronavirus

New and fascinating physical, chemical and biological phenomena arise in ultra-small materials, such as graphene. Graphene is a single layer formed only for carbon atoms, super-strong, 200 times stronger than steel and as much as 6 times lighter. It also has a high elasticity and densi-ty. Furthermore, it seems to be impermeable to almost everything, but allows the passage of water and air. Due to its versatility, modern and urgent applications arise every day, one of the most ne-cessary, currently, is the control of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the novel coronavirus disease (COVID-19), which has dimensions around 100 nm and has caused a worldwide public health emergency. Different ways to prevent coronavirus contagion has proposed and one of them is the use of masks. Here, we investigated some properties of graphene that can help combat COVID-19. A scale appropriate for comparison shows that the spatial dimension of a virus is much larger than the graphene sheet, making it a great candidate for manufacturing face masks, filters and respirators. We also make use of first-principles calculations, based on the density functional theory (DFT), to investigate the interaction between graphene and a water molecule. We observed that the water molecule undergoes a repul-sion force when it is very close to the graphene sheet. The hydrophobicity of graphene can be important to prevent the face mask that doesn't get wet when you breathe with it.Copyright © 2021 Bentham Science Publishers.

DFT, ADMET, molecular docking and molecular dynamics studies of pyridoxal

We report in silico studies of pyridoxal, which is of interest both as a precursor for further functionalization due to the presence of the aldehyde functionality, as well as a bioactive compound. So far, the crystal structure of pyridoxal has not been reported and, thus, we have optimized its structure both under water solvation and in gas phase using the DFT calculations. Under water solvation conditions the optimized structure of pyridoxal is 7.62 kcal/mol more favorable in comparison to that in gas phase. The DFT calculations were also applied to verify optical and electronic properties of the optimized structure of pyridoxal in water. The HOMO and LUMO were revealed to subtract a set of descriptors of the so-called global chemical reactivity as well as to probe pyridoxal as a potential corrosion inhibitor for some important metals used in implants. The title compound exhibits the best electron charge transfer from the molecule to the surface of Ni and Co. Some biological properties of pyridoxal were evaluated using the respective on-line tools. Molecular docking was additionally applied to study interaction of pyridoxal with some SARS-CoV-2 proteins as well as one of the monkeypox proteins. It was established that the title compound is active against all the applied proteins with the most efficient interaction with nonstructural protein 15 (endoribonuclease) and Omicron Spike protein of SARS-CoV-2. Pyridoxal was found to be also active against the studied monkeypox protein. Interaction of pyridoxal with nonstructural protein 15 (endoribonuclease) was further studied using molecular dynamics simulation.Copyright © 2023 Indian Chemical Society

Electronic, intermolecular, quantum computational investigations, molecular docking and simulation studies of the potent antiviral drug EIDD-2801

In this work, an analysis has been done to describe the molecular structure, spectroscopic, reduced density gradient, topological properties, atomic charges, Lipinski rule, Natural bond orbital analysis, docking and molecular dynamics simulation of the potent antiviral drug EIDD-2801 in the effective treatment against COVID-19. Intramolecular charge distribution is well understood by three schemes such as AIM, Mulliken and NBO analysis and non-covalent interactions have been understood through reduced density gradient. Topological properties, such as charge density and Laplacian of charge density along with the electron localization function, make it easy to obtain comprehensive information about bond strengths and critical points. The details obtained from the calculation of global reactivity descriptors and Lipinski rule are useful for understanding the nature of molecular reactivity and site selectivity. Electrostatic potentials help to identify potential electrophilic and nucleophilic sites for interaction between EIDD-2801 and target proteins. The molecular docking combined with molecular dynamic simulation studies enables us to get better picture about the ligand-protein interaction.Copyright © 2023 Indian Chemical Society

A comparative DFT study on Al- and Si- doped single-wall carbon nanotubes (SWCNTs) for Ribavirin drug sensing and detection

In this work, we have presented a comparative study on Ribavirin (RBV) drug sensing and detection on the pristine and functionalized single-wall carbon nanotubes (f-SWCNTs) by Density Functional Theory (DFT) method. The pristine and metal-doped zigzag (4,0) and (6,0) SWCNTs were first considered for the RBV adsorption. All the probable positions of RBV adsorption were investigated to find which one is energetically favourable. The topology analysis of the Quantum theory of atoms in a molecule (QTAIM) with non-covalent interactions (NCI-RDG), Frontier molecular orbitals (FMO), Density of states (DOS), and non-linear optical (NLO) analysis were carried out to understand the molecular structure, electrical, electronic and optical properties of complexes. The charge analysis indicates that charge transfer is from the adsorbed RBV to the pristine and metal-doped (4,0) and (6,0) SWCNTs. The highest values of adsorption energies for Al-, Si-doped and pristine (4,0) SWCNTs were determined as −34.688, −87.999 and −10.382 kcal/mol, respectively, whereas corresponding values for metal-doped and pristine (6,0) SWCNTs are about −43.592, −20.661 and −12.414 kcal/mol, respectively. The results suggest that those bare and metal-doped (4,0) SWCNTs and (6,0) Si-SWCNTs can serve as promising sensors in practical applications to detect, recognize and carrier RBV drug for its medicinal drug delivery applications. Based on the NLO properties of (6,0) Si-SWCNTs and pristine (6,0) SWCNT (with an acceptable recovery time of 279s and first hyper polarizability value of β = 229.25 × 10−30 cm5 esu−1), those nanotubes may be possible candidates to be used as the optoelectronic sensor for RBV drug. The appropriate short length of nanotubes was obtained. © Elsevier Ltd

Molecularly imprinted polymer-modified carbon paste electrodes (MIP-CPE): A review on sensitive electrochemical sensors for pharmaceutical determinations

Recent years have been associated with the development of various sensor-based technologies in response to the undeniable need for the rapid and precise analysis of an immense variety of pharmaceuticals. In this regard, special attention has been paid to the design and fabrication of sensing platforms based on electrochemical detection methods as they can offer many advantages, such as portability, ease of use, relatively cheap instruments, and fast response times. Carbon paste electrodes (CPEs) are among the most promising conductive electrodes due to their beneficial properties, including ease of electrode modification, facile surface renewability, low background currents, and the ability to modify with different analytes. However, their widespread use is affected by the lack of sufficient selectivity of CPEs. Molecularly imprinted polymers (MIPs) composed of tailor-made cavities for specific target molecules are appealing complementary additives that can overcome this limitation. Accordingly, adding MIP to the carbon paste matrix can contribute to the required selectivity of sensing platforms. This review aims to present a categorized report on the recent research and the outcomes in the combinatory fields of MIPs and CPEs for determining pharmaceuticals in complex and simple matrices. CPEs modified with MIPs of various pharmaceutical compounds, including analgesic drugs, antibiotics, antivirals, cardiovascular drugs, as well as therapeutic agents affecting the central nervous system (CNS), will be addressed in detail.Copyright © 2023 Elsevier B.V.

Ligational behavior of bidentate nitrogen–oxygen donor 8‐quinolinolazodye toward Ni2+ and Zn2+ ions: Preparation, spectral, thermal, experimental, theoretical, and docking studies

The 5‐(4‐aryl azo)‐8‐hydroxyquinolines (L1–L3) and their metal complexes with Ni2+ and Zn2+ have been produced. Various spectroscopic techniques have been employed to analyze the ligand and complexes. The structures of the prepared compounds have been confirmed by Fourier transform infrared (FT‐IR), proton nuclear magnetic resonance (1H NMR), molar conductance, magnetic measurements, thermal gravimetric and differential thermal analyses (TG and DTA), and electronic transition. The FT‐IR spectra showed that the ligands are coordinated to the metal ions in a bidentate manner with donor sites of the azomethine‐N and phenolic‐OH. The FT‐IR and UV–Visible spectra were compared with the calculated results and showed a good agreement. The mass spectra concluded that the ligands' molecular weights and the calculated estimated m/z values match well. The complexes contain coordinated and hydrated water as confirmed by the TG results. The complexes are tetrahedral, trigonal bipyramid, and octahedral geometrical structures and act as non‐electrolytes in dimethylformamide (DMF) solvent. Using density functional theory (DFT) at the B3LYP level of theory and the 6‐311G** basis set for the C, H, N, Cl, and O atoms and the LANL2DZ basis set for the Ni and Zn atoms. Natural bond orbital (NBO) analysis was used to compute and describe the natural charge population and precise electronic configuration. The small energy gap between HOMO and LUMO energies suggests that charge transfer occurs within Ni2+ and Zn2+ complexes. The first‐order hyperpolarizability (β) of the complexes and the anisotropy of polarizability (α) values show promising optical properties. The electronic transitions of the prepared complexes were computed by time‐dependent density functional theory (TD‐DFT/PCM) with the B3LYP method using a 6‐31G** basis set. The ethanol polarizable continuum model (PCM) was used to simulate the solvent effect. Utilizing a computer virtual screening technique through molecular docking, the anticipation of binding of 8‐quinolinolazodye derivatives and their complexes with human CORONA virus protein (PDB ID: 5epw) was done. [ FROM AUTHOR] Copyright of Applied Organometallic Chemistry is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Anti-COVID-19 Sulfonamides: A DFT, Docking and ADMET Study

Background: The development of a specific curative drug or prophylactic and vaccine is urgently required to cure COVID-19. Sulfonamide and its derivatives are famous for their multi-faceted antibiotic and antiviral activities against verities of a pathogen. Objective(s): The objective of this study is to find new potential molecules for COVID-19 treatment. We tested some sulfonamide molecules (including antiviral compounds) as SARS CoV-2 Mpro in-hibitors. Method(s): In this study, the Density Functional Theory (DFT) and Docking study have been util-ized for protein-small molecule affinity prediction. The SwissADME server was used for pharma-cokinetics and drug-like likeness prediction, and the Pred-hERG server was employed for cardio-toxicity prediction. Result(s): In this study, sixteen sulfonamides have been investigated in silico, with a perspective to obtaining a potential anti-covid compound. The sulfonamides have been subjected to molecular docking with SARS CoV-2 Mpro, mainly responsible for viral infection and replication. We discov-er the molecular flexibility and charge distribution profoundly affecting the binding of the compounds to the protein. Moderately flexible (six rotatable bond) and less polar (sufficient hydropho-bic) sulfonamide are favorable for strong binding with the enzyme. Here, the bioavailability proper-ties like adsorption, distribution, metabolism, excretion, pharmacokinetics, and potential toxicity of these compounds have also been checked. Conclusion(s): Low cardio-toxicity and high bioavailability make these sulfonamides a good anti-COVID-19 drug option. The sulfonamide 16 was found to be the best.Copyright © 2022 Bentham Science Publishers.

Machine Learning-Assisted Sensor Based on CsPbBr3@ZnO Nanocrystals for Identifying Methanol in Mixed Environments.

Methanol is a respiratory biomarker for pulmonary diseases, including COVID-19, and is a common chemical that may harm people if they are accidentally exposed to it. It is significant to effectively identify methanol in complex environments, yet few sensors can do so. In this work, the strategy of coating perovskites with metal oxides is proposed to synthesize core-shell CsPbBr3@ZnO nanocrystals. The CsPbBr3@ZnO sensor displays a response/recovery time of 3.27/3.11 s to 10 ppm methanol at room temperature, with a detection limit of 1 ppm. Using machine learning algorithms, the sensor can effectively identify methanol from an unknown gas mixture with 94% accuracy. Meanwhile, density functional theory is used to reveal the formation process of the core-shell structure and the target gas identification mechanism. The strong adsorption between CsPbBr3 and the ligand zinc acetylacetonate lays the foundation for the formation of the core-shell structure. The crystal structure, density of states, and band structure were influenced by different gases, which results in different response/recovery behaviors and makes it possible to identify methanol from mixed environments. Furthermore, due to the formation of type II band alignment, the gas response performance of the sensor is further improved under UV light irradiation.

Investigation of Bucillamine as anti-COVID-19 drug: DFT study, molecular docking, molecular dynamic simulation and ADMET analysis.

The novel coronavirus disease-2019 (COVID-19), caused by SARS-CoV-2, is a global health pandemic beginning in early December 2019 in Wuhan, Hubei province, China. The effective drug target among coronaviruses is the SARS-CoV-2 main protease (Mpro), because of its crucial role in processing viral polyproteins translated from the viral RNA. In this study, the bioactivity of the selected thiol drug named Bucillamine (BUC) was evaluated as a potential drug for COVID-19 treatment by using computational modeling strategies. First, the molecular electrostatic potential density (ESP) calculation was performed to estimate the chemically active atoms of BUC. Additionally, BUC was docked to the Mpro (PDB: 6LU7) to evaluate the protein-ligand binding affinities. Besides, the estimated ESP results by density functional theory (DFT) were used to illustrate the molecular docking findings. Moreover, the frontier orbitals analysis was calculated to determine the charge transfer between the Mpro and BUC. Then, the stability of protein-ligand complex was subjected to the molecular dynamic simulations. Finally, an in silico study was performed to predict drug-likeness and absorption, distribution, metabolism, excretion and toxicity profiles (ADMET) of BUC. These results propose that BUC can be a potential drug candidate against the COVID-19 disease progression.Communicated by Ramaswamy H. Sarma.

Selected dechlorination of triclosan by high-performance g-C3N4/Bi2MoO6 composites: Mechanisms and pathways

Environmental-friendly and efficient strategies for triclosan (TCS) removal have received more attention. Influenced by COVID-19, a large amount of TCS contaminants were accumulated in medical and domestic wastewater discharges. In this study, a unique g-C3N4/Bi2MoO6 heterostructure was fabricated and optimized by a novel and simple method for superb photocatalytic dechlorination of TCS into 2-phenoxyphenol (2-PP) under visible light irradiation. The as-prepared samples were characterized and analyzed by XRD, BET, SEM, XPS, etc. The rationally designed g-C3N4/Bi2MoO6 (4:6) catalyst exhibited notably photocatalytic activity in that more than 95.5% of TCS was transformed at 180 min, which was 3.6 times higher than that of pure g-C3N4 powder. This catalyst promotes efficient photocatalytic electron-hole separation for efficient dechlorination by photocatalytic reduction. The samples exhibited high recyclable ability and the dechlorination pathway was clear. The results of Density Functional Theory calculations displayed the TCS dechlorination selectivity has different mechanisms and hydrogen substitution may be more favorable than hydrogen ion in the TCS dechlorination hydrogen transfer process. This work will provide an experimental and theoretical basis for designing high-performance photocatalysts to construct the systems of efficient and safe visible photocatalytic reduction of aromatic chlorinated pollutants, such as TCS in dechlorinated waters. © 2022 Elsevier Ltd