Comparable Binding Energies Research Articles

One‐Pot Synthesis of Fused Isoxazolo[4′,5′:3,4]pyrrolo[2,1‐b] Quinazolines as Potent EGFR Targeting Anticancer Agents

AbstractIn response to the need for scaffolds for medical applications, synthetic chemists have developed simple and efficient methods for optimal synthesis. To investigate the synthesis of fused isoxazoles in the presence of [3+2] cycloaddition followed by C−N bond formation reaction between 3‐((4‐iodo‐3‐phenylisoxazol‐5‐yl)methyl)quinazolin‐4(3H)‐one and various nitrile oxides was carried out by previously reported conditions. The cancer activities of the synthesized compounds were then tested in vitro against two cancer cell lines, MCF‐7 and A‐549. Three of the compounds, 3‐(3,5‐dichlorophenyl) isoxazolo[4′,5′:3,4]pyrrolo[2,1‐b]quinazolin‐9(11H)‐one, 3‐(4‐fluorophenyl)isoxazolo[4′,5′:3,4]pyrrolo[2,1‐b]quinazolin‐9(11H)‐one, and 3‐(4‐(trifluoromethyl)phenyl)isoxazolo[4′,5′:3,4] pyrrolo[2,1‐b] quinazolin‐9(11H)‐one has shown superior activity against the non‐small‐cell lung cancer cell line (A‐549) than the standards 5‐fluorouracil and erlotinib. Later, in vitro EGFR results revealed that a more potent compound was more effective than the conventional medicine, erlotinib. In silico investigations of more potent compounds and erlotinib on the EGFR protein indicated that more potent compounds had comparable binding energies and inhibition constants to erlotinib.

Widely-targeted in silico and in vitro evaluation of veratrum alkaloid analogs as FAK inhibitors and dual targeting of FAK and Hh/SMO pathways for cancer therapy: A critical analysis

Focal Adhesive Kinase (FAK), a key player in aggressive cancers, mediates signals crucial for progression, invasion, and metastasis. Despite advances in targeted therapies, drug resistance is still a challenge, and survival rates remain low, particularly for late-stage patients, emphasizing the need for innovative cancer therapeutics. Cyclopamine, a veratrum alkaloid, has shown promising anti-tumor properties, but the search for more potent analogs with enhanced affinity for the biological target continues.This study employs a hybrid virtual screening approach combining pharmacophore model-based virtual screening (PB-VS) and docking-based virtual screening (DB-VS) to identify potential inhibitors of the FAK catalytic domain. PB-VS on the PubChem database yielded a set of hits, which were then docked with the FAK catalytic domain in two stages (1st and 2nd DB-VS). Hits were ranked based on docking scores and interactions with the active site. The top three compounds underwent molecular dynamics simulations, alongside two control compounds (SMO inhibitor(s) and FAK inhibitor(s)), to assess stability through RMSD, RMSF, Rg, and SASA analyses. ADMET properties were evaluated, and compounds were filtered based on drug-likeness criteria.Molecular dynamics simulations demonstrated the stability of compounds when complexed with the FAK catalytic domain. Compounds 16 (−25 kcal/mol), 88 (−27.47 kcal/mol), and 87 (−18.94 kcal/mol) exhibited comparable docking scores, interaction profiles, stability, and binding energies, indicating their potential as lead candidates. However, further validation and optimization through quantitative structure-activity relationship (QSAR) studies are essential to refine their efficacy and therapeutic potential. The in vitro cell-based assay demonstrated that compound 101PF, a FAK inhibitor, significantly inhibited the proliferation and migration of A549 cells. However, the results regarding the combined effects of FAK and SMO inhibitors were inconclusive, highlighting the need for further investigation. This study contributes to developing more effective anti-cancer drugs by improving the understanding of potential cyclopamine-based veratrum alkaloid analogs with enhanced interactions with the FAK catalytic domain.

Computational Screening of FDA‐Approved Hepatitis C Drugs for Inhibition of VEGFR2 in Liver Cancer

AbstractLiver cancer (LC) is one of the most common tumours and the leading cause of cancer‐related death globally. Amidst the problems associated with existing treatments, such as hepatotoxicity, recurrence, drug resistance, and other adverse effects, researchers are under pressure to find alternatives. Towards a comprehensive rationalisation of the search for new anti‐LC drugs among approved ones, we employed an in‐silico approach to accelerate the selection of the most efficacious LC drugs. The FDA‐approved hepatitis C virus (HCV) drugs were docked with the LC protein using the AutoDock Vina software. Compared to the control compound, two FDA‐approved HCV drugs (DB09102 and DB09027) were selected based on their binding energies and interactions with the target protein, which showed comparable binding energies. Furthermore, these compounds were then subjected to molecular dynamic simulation, principle component analysis, and MMGBSA using the AMBER20 software, and the results showed stable complexes compared to the control complex. All things considered, this study will help the scientific community and society find a novel drug to treat LC.

Metal-free internal nucleophile-triggered domino route for synthesis of fused quinoxaline [1,4]-diazepine hybrids and the evaluation of their DNA binding properties

An unprecedented metal-free synthesis of fused quinoxaline 1,5-disubstituted-[1,4]-diazepine hybrids have been reported under mild conditions through a domino intermolecular SNAr followed by an internal nucleophile-triggered intramolecular SNAr pathway. Our strategy offers the flexibility for the introduction of a broad variety of functionalities at the N-1 position of fused diazepine moiety by using suitable diamine tails to design structurally diverse scaffolds. The DNA binding properties of representative quinoxaline diazepine hybrids were studied using UV–vis absorbance and EtBr displacement assay and were found to be governed by the functionalities at the N-1 position. Interestingly, compound 11f containing the N-1 benzyl substitution demonstrated significant DNA binding (KBH ∼ 2.15 ± 0.25 × 104 M−1 and Ksv ∼ 12.6 ± 1.41 × 103 M−1) accompanied by a bathochromic shift (Δλ ∼ 5 nm). In silico studies indicated possible binding of diazepine hybrid 11f at the GC-rich major groove in the ct-DNA hexamer duplex and showed comparable binding energies to that of ethidium bromide. The antiproliferative activity of compounds was observed in the given order in different cell lines: (HeLa > HT29 > SKOV 3 > HCT116 > HEK293). Lead compound 11f demonstrated maximum cytotoxicity (IC50 value of 13.30 μM) in HeLa cell lines and also caused early apoptosis-mediated cell death in cancer cell lines. We envision that our work will offer newer methodologies for the construction of fused quinoxaline 1,5-disubstituted-[1,4]-diazepine class of molecules.

Synthesis, Characterization, Molecular Docking, and Molecular Dynamics Studies of Schiff Bases of 2-Phenoxy-1-Phenyl-Ethanone as Antibacterial Agents

Background: The development of antimicrobial resistance and reduced discovery and commercialization of newer antibiotics point to the need for the discovery of novel anti-bacterial agents. Schiff bases are reported to possess a broad range of pharmacological activi-ties, which also include antibacterial activity. With this background, novel Schiff bases were synthesized. Aim: The present study aimed to synthesize novel Schiff bases of 2-phenoxy-1-phenyl-etha-none with aryl amines and evaluate their antibacterial activity. Methods: The desired Schiff bases were synthesized by condensing various aryl amines with 2-bromo-1-phenylethanone and characterized by physicochemical and spectral methods. The antibacterial activity of the synthesized Schiff bases was determined by the cup diffusion method. Molecular docking with Staphylococcus aureus tyrosyl-t-RNA synthetase (Protein Data Bank ID: 1JIJ) was performed using Autodock. Molecular dynamics simulation studies were performed using GROMACS. ADME analysis and drug-likeliness of the synthesized compounds were predicted using SwissADME. Protein-ligand interactions were studied using BIOVIA Discovery Studio Visualizer. Results: Out of the synthesized compounds, two compounds, sb_04 and sb_05, exhibited fair antibacterial activity. The compounds sb_04 and sb_05 exhibited better binding energy values than the original ligand of the target enzyme and comparable binding energy with ampicillin. The Autodock program estimated the binding free energy and inhibition constant values of compound sb_05 as -9.18 kcal/mol and 187.33 nM and for the compound sb_04 as -8.82 kcal/mol and 341.59 nM, respectively. The RMSD values of the compound sb_04 were stable throughout the duration of the simulation; however, the compound sb_05 showed lesser sta-bility in the docked complex. Interestingly, the compound sb_05 (-182.754 kJ/mol) exhibited stable interaction with a lower value of total interaction energy than sb_04 (-136.304 kJ/mol). The synthesized Schiff bases showed no violation of Lipinski’s rule of five and a bioavailabil-ity score in the range of 55% to 85%. Conclusion: The synthesized Schiff bases present a scaffold for the development of novel antibacterial agents, in particular the compounds sb_04 and sb_05.

Molecular structure, molecular docking, molecular dynamics simulation, and drug likeness evaluation of 3,7-dihydroxy-1,2-dimethoxyxanthone for its anticancer activity

A naturally occurring xanthone, named 3,7-dihydroxy-1,2-dimethoxyxanthone was experimentally and computationally investigated for its anticancer activity. Single crystal X-ray diffraction (XRD) analysis revealed that the compound crystallises in the triclinic space group P1. Vibrational frequencies, electronic properties, chemical reactivity descriptors, the molecular structure, and stability of the compound were investigated by DFT calculations using Gaussian 09 W program at the B3LYP/6–311+G(2d,p) level of theory. All calculations showed correlations to experimental data. Its thermodynamic parameters at various temperatures are presented. The title molecule was docked on the proteins of prostate, cervical, breast, and melanoma cancer cells, and the results showed comparable binding energies to the standard chemotherapeutic agent, doxorubicin with small differences in the range 0.2−0.7 kcal mol−1. Given that the compound showed significant potential on the proteins of prostate and cervical cancer cells, the dynamic properties of the bound state of title ligand with the two selected proteins were further examined through a 200 ns molecular dynamics simulation. The results showed relatively overall higher stability through the simulation time than the free target. All these findings were afterwards confirmed by the good in vitro inhibition activity of the compound against human prostate and cervical cancer cell lines with IC50 values of 9.55 and 9.19 µM, respectively in comparison to the standard drug, and additionally demonstrated innocuousness towards normal human kidney cancer cell lines. Moreover, the drug likeness properties indicated that the title compound has a high bioavailability, a good water solubility, a good gastrointestinal absorption, and can be easily synthesized.

Roles of lattice and grain boundary on hydrogen diffusion and trap behaviors in single-and poly-crystalline CrCoNi medium-entropy alloy

In this study, single-crystalline and poly-crystalline CrCoNi alloys are utilized as model systems to analyze the distinct roles of each GB and interstitial lattice sites. To effectively reveal hydrogen behavior, both electrochemical and gaseous hydrogen pre-charging methods are applied. Hydrogen content, diffusivity, and trap behaviors are quantified using thermal desorption analysis and hydrogen permeation tests, which determines (1) changes in hydrogen behavior depending on the presence of GB and (2) alterations in hydrogen behavior depending on lattice crystallographic orientation. The results indicate that GB and interstitial lattice sites exhibit comparable binding energies for hydrogen trapping. However, the introduction of GB alters the primary trapping sites from interstitial lattice sites to GB. In this case, the hydrogen content in the poly-crystalline alloy is determined by the trap site density of the primary trapping site. On the other hand, in the single-crystalline alloy, where only interstitial lattice sites exist, the crystallographic orientation of the hydrogen-charged plane is an important variable that determines hydrogen content and hydrogen diffusivity. Such insights contribute to a deeper understanding of hydrogen behavior within a more intricate microstructure, suggesting the alloy design approach to enhance resistance to HE.

Evaluation of suitability and biodegradability of the organophosphate insecticides to mitigate insecticide pollution in onion farming

Organophosphates constitute a major class of pesticides widely employed in agriculture to manage insect pests. Their toxicity is attributed to their ability to inhibit the functioning of acetylcholinesterase (AChE), an essential enzyme for normal nerve transmission. Organophosphates, especially chlorpyrifos, have been a key component of the integrated pest management (IPM) in onions, effectively controlling onion maggot Delia antiqua, a severe pest of onions. However, the growing concerns over the use of this insecticide on human health and the environment compelled the need for an alternative organophosphate and a potential microbial agent for bioremediation to mitigate organophosphate pesticide pollution. In the present study, chloropyrifos along with five other organophosphate insecticides, phosmet, primiphos-methyl, isofenphos, iodofenphos and tribuphos, were screened against the target protein AChE of D. antiqua using molecular modeling and docking techniques. The results revealed that iodofenphos showed the best interaction, while tribuphos had the lowest interaction with the AChE based on comparative binding energy values. Further, protein-protein interaction analysis conducted using the STRING database and Cytoscap software revealed that AChE is linked with a network of 10 different proteins, suggesting that the function of AChE is disrupted through interaction with insecticides, potentially leading to disruption within the network of associated proteins. Additionally, an in silico study was conducted to predict the binding efficiency of two organophosphate degrading enzymes, organophosphohydrolase (OpdA) from Agrobacterium radiobacter and Trichoderma harzianum paraoxonase 1 like (ThPON1-like) protein from Trichoderma harzianum, with the selected insecticides. The analysis revealed their potential to degrade the pesticides, offering a promising alternative before going for cumbersome onsite remediation.

Identification of novel hit molecules targeting M. tuberculosis polyketide synthase 13 by combining generative AI and physics-based methods

In this work we investigated the Pks13-TE domain, which plays a critical role in the viability of the mycobacteria. In this report, we have used a series of AI and Physics-based tools to identify Pks13-TE inhibitors. The Reinvent 4, pKCSM, KDeep, and SwissADME are AI-ML-based tools. AutoDock Vina, PLANTS, MDS, and MM-GBSA are physics-based methods. A combination of these methods yields powerful support in the drug discovery cycle. Known inhibitors of Pks13-TE were collected, curated, and used as input for the AI-based tools, and Mol2Mol molecular optimisation methods generated novel inhibitors. These ligands were filtered based on physics-based methods like molecular docking and molecular dynamics using multiple tools for consensus generation. Rigorous analysis was performed on the selected compounds to reduce the chemical space while retaining the most promising compounds. The molecule interactions, stability of the protein-ligand complexes and the comparable binding energies with the native ligand were essential factors for narrowing the ligands set. The filtered ligands from docking, MDS, and binding energy colocations were further tested for their ADMET properties since they are among the essential criteria for this series of molecules. It was found that ligands Mt1 to Mt6 have excellent predicted pharmacokinetic, pharmacodynamic and toxicity profiles and good synthesisability.

Ni-based plasmonic photocatalysts for solar to energy conversion: A review

Plasmonic-based semiconductors are compelling contenders of current research endeavors to drive chemical reactions via plasmonic and phononic light-matter interactions. Among various plasmonic metals, Ni as a non-precious metal has been extensively studied due to its ability to participate in interband excitation and comparable metal-hydrogen binding energy to that of noble metals including Pt and Ag. The phenomenally high charge-carrier density in photoexcited Ni-based plasmonic nanomaterials offers photochemical conversion of high-energy chemical bonds accompanied by thermal effect. Since the research on the plasmonic activity of the non-precious metal is still emerging, no comprehensive review has addressed the significance of Ni as a plasmonic photocatalyst to the best of our knowledge. This review article sums up the recent progress in the field of plasmonic photocatalysis focusing on Ni-based photocatalysts. The basic principles of the plasmonic effect have been presented, along with an explanation of why Ni may be a viable option. Ni has been investigated for use as a co-catalyst and plasmonic photocatalyst in composite photocatalysis to achieve an accelerated process. After the energy transfer mechanism has been assessed, the review covers the state-of-the-art of two significant effects—plasmon energy transfer and the localized heating effect that are responsible for increased efficiency in energy production. In conclusion, we have included a synopsis of the assessment and emphasized the problems that must be resolved before the technology can be made available for purchase. In a nutshell, the chemistry of plasmonic photocatalysis is promising; but acquiring a detailed mechanism of charge transfer and utilization of charge carriers is still a roadblock in apprehending the full potential of plasmonic photocatalysis. Therefore, this study aims to motivate the scientific community to envision impactful work in the creation of next-generation plasmonic photocatalysts.

Synthesis and anti-breast cancer evaluation of fused imidazole-imidazo[1,2-c][1,2,3]triazoles: PEG-400 mediated one-pot reaction under ultrasonic irradiation

Synthetic chemists have organized easy and effective ways for perfect synthesis in response to the requirement for scaffolds that are crucial for medical applications. To investigate the synthesis of fused 1,2,3-triazoles in the presence of ultrasound, the [3 + 2] cycloaddition followed by CN bond formation reaction between 2-chloro-N-(1-methyl-1H-imidazol-2-yl)acetamide and substituted aryl iodoalkynes was carried out ourpreviously reported condition. The cancer activity of the synthesized compounds were then tested in vitro against two breast cancer cell lines MCF-7 and MDA-MB231 and some of the compounds 5g and 5j showed more potent activity against MCF-7 compared to standard erlotinib (IC50 = 4.70 ± 0.11 μM) with IC50 values 4.02 ± 0.74 and 4.23 ± 0.65 μM. Later, in vitro EGFR results revealed that compound 5g (IC50 = 0.38 ± 0.02 μM) have shown more effective than the conventional medicine erlotinib (IC50 = 0.42 ± 0.04 μM). Compounds 5j (IC50 = 0.42 ± 0.05 μM) have shown equipotent, 5i (IC50 = 0.53 ± 0.02 μM) and 5k (IC50 = 0.58 ± 0.02 μM) were shown good activity compared to the standard erlotinib. In silico investigations of more potent compounds (5g, 5i, 5j, 5k, and 5q) and erlotinib on the EGFR protein indicated that all five compounds had comparable binding energies and inhibition constants than the erlotinib.

Similar Binding Modes of cGMP Analogues Limit Selectivity in Modulating Retinal CNG Channels via the Cyclic Nucleotide-Binding Domain.

In treating retinitis pigmentosa, a genetic disorder causing progressive vision loss, selective inhibition of rod cyclic nucleotide-gated (CNG) channels holds promise. Blocking the increased Ca2+-influx in rod photoreceptors through CNG channels can potentially delay disease progression and improve the quality of life for patients. To find inhibitors for rod CNG channels, we investigated the impact of 16 cGMP analogues on both rod and cone CNG channels using the patch-clamp technique. Although modifications at the C8 position of the guanine ring did not change the ligand efficacy, modifications at the N1 and N2 positions rendered cGMP largely ineffective in activating retinal CNG channels. Notably, PET-cGMP displayed selective potential, favoring rod over cone, whereas Rp-cGMPS showed greater efficiency in activating cone over rod CNG channels. Ligand docking and molecular dynamics simulations on cyclic nucleotide-binding domains showed comparable binding energies and binding modes for cGMP and its analogues in both rod and cone CNG channels (CNGA1 vs CNGA3 subunits). Computational experiments on CNGB1a vs CNGB3 subunits showed similar binding modes albeit with fewer amino acid interactions with cGMP due to an inactivated conformation of their C-helix. In addition, no clear correlation could be observed between the computational scores and the CNG channel efficacy values, suggesting additional factors beyond binding strength determining ligand selectivity and potency. This study highlights the importance of looking beyond the cyclic nucleotide-binding domain and toward the gating mechanism when searching for selective modulators. Future efforts in developing selective modulators for CNG channels should prioritize targeting alternative channel domains.

Exploring the anti-acne potential of Muntingia calabura L leaves against Staphylococcus epidermidis: In vitro and in silico perspective

Introduction: Muntingia calabura is a medicinal plant possessing antimicrobial properties against various bacteria. The purpose of this study was to examine in vitro and in silico activity of the ethyl acetate fraction of M. calabura leaves against the acne-causing commensal bacterium, Staphylococcus epidermidis. Methods: In this study, M. calabura leaves were extracted using ethanol and then further fractionated with ethyl acetate. The phytochemicals in the fraction were identified with thin layer chromatography (TLC). The activity of the fraction was then tested in S. epidermidis culture using the agar diffusion method. Additionally, the molecular docking of M. calabura phytochemicals constituents was simulated to teicoplanin-associated locus regulator (TcaR) of S. epidermidis. Results: The ethyl acetate fraction of M. calabura exhibited robust antibacterial activity against S. epidermidis culture, resulting in inhibition zones ranging from 5 to 10 mm. The fraction was found to contain flavonoids, saponins, and tannins as identified constituents. Further, during the molecular docking analysis, stigmasterol and 7-methoxyflavone demonstrated binding to TcaR with a lower and comparable binding energy of -7.40 and -6.19 kcal/mol, respectively, compared to the control drug, Penicillin-G (-6.40 kcal/mol). Conclusion: M. calabura has the potential to serve as a valuable source of active phytochemical compounds for addressing acne. Further studies are needed to isolate and evaluate each compound found in M. calabura individually against S. epidermidis.

Cyclodextrins: Establishing building blocks for AI-driven drug design by determining affinity constants in silico

Cyclodextrins (CDs) are cyclic carbohydrate polymers that hold significant promise for drug delivery and industrial applications. Their effectiveness depends on their ability to encapsulate target molecules with strong affinity and specificity, but quantifying affinities in these systems accurately is challenging for a variety of reasons. Computational methods represent an exceptional complement to in vitro assays because they can be employed for existing and hypothetical molecules, providing high resolution structures in addition to a mechanistic, dynamic, kinetic, and thermodynamic characterization. Here, we employ potential of mean force (PMF) calculations obtained from guided metadynamics simulations to characterize the 1:1 inclusion complexes between four different modified βCDs, with different type, number, and location of substitutions, and two sterol molecules (cholesterol and 7-ketocholesterol). Our methods, validated for reproducibility through four independent repeated simulations per system and different post processing techniques, offer new insights into the formation and stability of CD-sterol inclusion complexes. A systematic distinct orientation preference where the sterol tail projects from the CD's larger face and significant impacts of CD substitutions on binding are observed. Notably, sampling only the CD cavity's wide face during simulations yielded comparable binding energies to full-cavity sampling, but in less time and with reduced statistical uncertainty, suggesting a more efficient approach. Bridging computational methods with complex molecular interactions, our research enables predictive CD designs for diverse applications. Moreover, the high reproducibility, sensitivity, and cost-effectiveness of the studied methods pave the way for extensive studies of massive CD-ligand combinations, enabling AI algorithm training and automated molecular design.

Association of epilepsy and neurological impairments with homozygous recessive missense mutations found in the genes responsible for ganglioside biosynthesis (ST3GAL5) and calcium voltage-gated channels (CACNA1H) - insights through molecular dynamic simulations

With over 2.2 million cases, the incidence rate of epilepsy in Pakistan is far higher than the rest of the world due primarily to the frequent, traditionally imposed cousin marriages. In the present study, comprehensive whole exome sequencing (WES) analyses of a three-generation family with four affected members presenting ‘unexplained’ childhood absence epilepsy (CAE), seizures and dementia, was performed in a quest to identify heritable, epilepsy-causal gene variants to better aid in carrier screening and genetic counselling. The WES data was generated, analyzed, and validated through Sanger’s sequencing, molecular dynamic simulation (MDS) analysis, and molecular mechanics with generalized Born and surface area solvation (MM/GBSA) studies. Two homozygous recessive, missense mutations in ST3GAL5 (c.311A > G, p. His104Arg) and CACNA1H (c.6230G > A, p. Arg2077His) genes, earlier regarded as benign or of uncertain significance, have been identified as a potential etiology. Comparative MDS and free binding energy calculations revealed substantial structural perturbations in mutant forms of ST3GAL5 leading to decreased binding and reduced catalytic activity of the p.His104Arg and two other functional variants (p.Val74Glu and p.Arg288Ter) when compared with wild type. Our findings reinforce that WES analyses may uncover ‘hidden’, heritable variants and together with MDS and MM/GBSA may provide plausible clues to answer the unexplained causes of epilepsy for an effective management and better patient outcome. Further, revisit of epilepsy-associated mutational landscape in population context is imperative as the variants with ‘benign’ tags may turn out to be ‘non-benign’, when exist in combination with other benign. Communicated by Ramaswamy H. Sarma

Adsorption and dehydrogenation of ammonia on Ru55, Cu55 and Ru@Cu54 nanoclusters: role of single atom alloy catalyst.

Hydrogen production by the catalytic decomposition of ammonia (NH3) is an important process for several important applications, which include energy production and environment-related issues. The role of single Ru-atom substitution in a Cu55 nanocluster (NC) has been illustrated using the NH3 decomposition reaction as a model system. The structural stability of Ru@Cu54 NC has been evaluated using Ru55 and Cu55 NCs for comparison. Ru@Cu54 prefers an icosahedron structure (Ih), like Ru55 and Cu55 NCs, with almost comparable average binding energies of -5.55 eV per atom. The adsorption of NHx (x = 0-3) on different adsorption sites of the icosahedron Ru@Cu54 NC has also been studied and the corresponding adsorption energies have been estimated. The site-preference investigation suggested that NH3 prefers to adsorb vertically to the Ru@Cu54. The stable geometries of the N and H atoms on the high symmetry adsorption sites of Ru@Cu54 NC have been studied. Although the N atom favours top and hollow sites, the H atom prefers to stay in the Ru-Cu bridge site along with the hollow sites. The adsorption energy of N on the Ru@Cu54 NC fcc site is found to be -5.42 eV, which is very close to the optimal value (-5.81 eV) of the ammonia decomposition volcano curve. The reaction energies for stepwise H atom elimination from an adsorbed NH3 molecule have been estimated. Finally, NH3 adsorption and decomposition on Ru@Cu54 have been illustrated in terms of electronic structure analysis. The energetics calculations for the dehydrogenation of NH3 suggest that Ru@Cu54 NC can be a suitable catalyst.

Molten Salt-Derived RuO2 Nanocrystals and Nanowires: Unveiling Correlations of Morphology, Microstructure, and Electrocatalytic Performance.

Ruthenium oxide (RuO2), due to its comparable binding energy with *H and cost-effectiveness against Pt, has emerged as a pivotal electrocatalyst for oxygen evolution reaction (OER). In the present study, RuO2 nanocrystals (NCs) and nanowires (NWs) were obtained by a molten salt process and the morphology, crystal structure, and local bonding features were examined by using electron microscopy and X-ray absorption spectroscopy. From the electrochemical measurement, both RuO2 NCs and NWs exhibit favorable stability and activity toward oxygen evolution reaction in an alkali medium, althought NCs exhibit higher activity, which is likely attributed to the larger surface area and the high local structural disorder. The theoretical calculation reveals that RuO2 NWs with a primary (110) orientation show a higher overpotential due to its d-band center's proximity to the Fermi level versus (101). The present work suggests that the molten salt process could be an efficient method for producing metal oxide catalysts with tailorable geometry and performances.

Efficient Green Synthesis, Anticancer Activity, and Molecular Docking Studies of Indolemethanes Using a Bioglycerol-Based Carbon Sulfonic Acid Catalyst.

Indolemethane derivatives are significant molecules in the study of N-heterocyclic chemistry. Herein, we designed and developed a highly efficient green synthesis of indolemethane compounds using a recyclable biodegradable glycerol-based carbon solid acid catalyst under solvent-free conditions at room temperature for 5 min with excellent yields. The synthesized compounds were subjected to cytotoxic activity against prostate (DU145), hepatocellular carcinoma (HepG2), and melanoma (B16) cell lines. The highest cytotoxicity effects were found with 1k (1.09 μM) and 1c (2.02 μM) against DU145, followed by 1a, 1d, 1f, 1n, and 1m between 5.10 and 8.18 μM concentrations. The anticancer activity is validated using molecular docking simulations, and comparing binding energies with the standard drug doxorubicin suggests that the title compounds are well fitted into the active site pocket of the target molecules..

Theoretical investigation of adsorption characteristics of typical additives for zinc electroplating.

Electroplated zinc layers have shown excellent corrosion resistance, especially those are stable in the atmosphere after the passivation, and therefore zinc electroplating is widely used in various fields such has mechanical, vehicle, construction, and ironware industries. Benzalacetone (BA) was reported as brighteners for zinc deposition, while polyoxyethylene nonylphenylether (NP) was used as levelers or carriers for zinc electroplating. Sodium benzoate (SB) and dispersant NNO cooperatively act as auxiliary additives. Quantum chemical parameters (QCPs) of four additives were calculated by using DFT, and MD simulations were performed. By comparing binding energies of four additives (benzalacetone (BA), sodium benzoate (SB), polyoxyethylene nonylphenylether (NP) and dispersant NNO), with Zn (001) surface, BA has the lowest binding energy, which is due to the lowest hardness parameter, and NNO has the highest binding energy, which is due to the highest dipole moment despite its small hardness parameter. For DFT calculation, NWChem was employed, which uses the Gaussian basis set. The B3LYP functional was used for exchange-correlation interaction between electrons, and the 6-311G+ (d,p) basis sets were used for all the atoms. Solvation effect was considered by using COSMO (COnductor-like Screening MOdel), in which the dielectric constant of solvent was set to 78.54 of water. For dispersion correction, DFT-D method of Tkatchenko and Scheffler (TS) was used. MD simulations were performed by using GULP (General Utility Lattice Program) code with Dreiding forcefield and atomic Hirshfeld charges from DFT calculations. MD simulations were performed on the conditions of NVT ensemble with a step of 1 fs and simulation time of 500 ps at 298 K and 323 K. To consider solvation effect, 1,000 water molecules were inserted into the box.

125I]INFT: Synthesis and Evaluation of a New Imaging Agent for Tau Protein in Post-Mortem Human Alzheimer's Disease Brain.

Aggregation of Tau protein into paired helical filaments causing neurofibrillary tangles (NFT) is a neuropathological feature in Alzheimer's disease (AD). This study aimed to develop and evaluate the effectiveness of a novel radioiodinated tracer, 4-[125I]iodo-3-(1H-pyrrolo[2,3-c]pyridine-1-yl)pyridine ([125I]INFT), for binding to Tau protein in postmortem human AD brain. Radiosynthesis of [125I]INFT was carried out using electrophilic destannylation by iodine-125 and purified chromatographically. Computational modeling of INFT binding on Tau fibril was compared with IPPI. In vitro, autoradiography studies were conducted with [125I]INFT for Tau in AD and cognitively normal (CN) brains. [125I]INFT was produced in >95% purity. Molecular modeling of INFT revealed comparable binding energies to IPPI at site-1 of the Tau fibril with an affinity of IC50 = 7.3 × 10-8 M. Binding of [125I]INFT correlated with the presence of Tau in the AD brain, confirmed by anti-Tau immunohistochemistry. The ratio of average grey matter (GM) [125I]INFT in AD versus CN was found to be 5.9, and AD GM/white matter (WM) = 2.5. Specifically bound [125I]INFT to Tau in AD brains was displaced by IPPI (>90%). Monoamine oxidase inhibitor deprenyl had no effect and clorgyline had little effect on [125I]INFT binding. [125I]INFT is a less lipophilic imaging agent for Tau in AD.