Strong Binding Energy Research Articles

Unsaturated bi‐heterometal clusters in metal‐vacancy sites of 2D MoS2 for efficient hydrogen evolution

AbstractThe valence states and coordination structures of doped heterometal atoms in two‐dimensional (2D) nanomaterials lack predictable regulation strategies. Hence, a robust method is proposed to form unsaturated heteroatom clusters via the metal‐vacancy restraint mechanism, which can precisely regulate the bonding and valence state of heterometal atoms doped in 2D molybdenum disulfide. The unsaturated valence state of heterometal Pt and Ru cluster atoms form a spatial coordination structure with Pt–S and Ru–O–S as catalytically active sites. Among them, the strong binding energy of negatively charged suspended S and O sites for H+, as well as the weak adsorption of positively charged unsaturated heterometal atoms for H*, reduces the energy barrier of the hydrogen evolution reaction proved by theoretical calculation. Whereupon, the electrocatalytic hydrogen evolution performance is markedly improved by the ensemble effect of unsaturated heterometal atoms and highlighted with an overpotential of 84 mV and Tafel slope of 68.5 mV dec−1. In brief, this metal vacancy‐induced valence state regulation of heterometal can manipulate the coordination structure and catalytic activity of heterometal atoms doped in the 2D atomic lattice but not limited to 2D nanomaterials.

Kinsenoside from Anoectochilus roxburghii (Wall.) Lindl. suppressed oxidative stress to attenuate aging-related learning and memory impairment via ERK/Nrf2 pathway

Ethnopharmacological relevanceAnoectochilusroxburghii (Wall.) Lindl. (AR), as an exceptionally valuable traditional Chinese medicine, has been widely used to treat hepatitis, cancer, diabetes, etc. But, the effects and the primary functioning element of AR on attenuating aging and aging-related learning and memory degradation has not yet been explored. Aim of the studyThis study aimed at exploring the protective property of aqueous extract of AR (AEAR) on alleviation of aging and aging-related learning and memory impairment in vivo, and further investigating the main active ingredient and mechanism of AEAR. Materials and methodsD-galactose (D-gal) induced aging mice and HT22 cells exposed with L-Glutamic acid (Glu) were used as in vivo and in vitro model, separately. The effects of AEAR on aging and aging-related learning and memory degradation were explored by using morris water maze test, immunohistochemistry staining, biochemistry assay, etc. The effects and mechanism of AEAR and Kinsenoside (Kin) on antioxidation in vitro were investigated by cell viability assay, biochemistry assay, qRT-PCR, western blotting and molecular docking studies. ResultsTreatment with AEAR (containing 69.52 ± 0.85% Kin, i.g.) for 63 days, alleviated low growth rate, abnormal brain, liver and thymus index, and decline in learning and memory capability of aging mice. Meanwhile, AEAR inhibited the decreased activities of SOD and GSH-PX, the decline in the ratio of GSH to GSSG, and the increase of MDA in both serum and brain, and also promoted the Nrf2 nuclear translocation in brain of aging mice induced by D-gal. The effects of AEAR on alleviating abnormal physiological characteristics, attenuating learning and memory impairment, and inhibiting oxidative stress in aging mice was similar to or even better than that of Vc. In HT22 cells exposed with Glu, Kin increased the cell viability, up-regulated the activities of SOD and GSH-PX, enhanced the ratio of GSH to GSSG, and down-regulated MDA, which was superior to AEAR. Kin up-regulated the ratio of p-ERK1/2 to ERK1/2, promoted the Nrf2 nuclear translocation and its downstream target genes, i.e. HO-1, NQO-1, GCLC and GCLM expression at the mRNA and protein levels, which were consistent with AEAR. Further, molecular docking results also confirmed that Kin had strong binding energy with ERK1 and ERK2. ConclusionThe present study indicated that Kin could alleviate the oxidative stress in aging mice via activating the ERK/Nrf2 signaling pathway, in order to attenuate aging and aging-related learning and memory impairment, as the main active ingredient of AR.

Ceragenin-CSA13 loaded high strength coatings of nano- and micro-SrHA implanted N-Carboxymethyl chitosan – Polyetheretherketone by low temperature high speed collision approach: In vitro pro-osteogenicity and bactericidal activity against MRSA

Cationic steroid antimicrobials (CSA13) loaded in the uniform coatings synthesized by micro and nano sized particles of strontium substituted hydroxyapatite implanted into the surface of N-carboxymethyl chitosan (N-CMCh) pre-embedded on polyetheretherketone (PEEK) substrate and their biocompatibility and antibacterial efficacy were investigated. Release of CSA13 from the nano SrHA implanted substrate showed faster release of the drug till 48 h with a release of 48% of total drug. It was found that CSA13 rich nano SrHA implanted substrate damaged the Methicillin Resistant Staphylococcus Aureus biofilm mass in 30 h, while micron sized SrHA implanted substrate reduced the biofilm mass to 27% at the same culture period. MG63 cell viability on these specimens exhibited significant cell growth even in the presence of CSA13. Nano SrHA implanted substrate showed better biocompatibility simultaneously providing antibacterial efficacy than the micro sized coating. The sustained release of CSA13 from the nano Sr-HA coating could be beneficial for long term eradication of infection. In silico docking approach between CSA13 and 1VQQ penicillin binding protein 2a from MRSA strain showed strong negative binding energy of (−) 68.78 kcal/mol demonstrating an in-visual predicting anti-bacterial efficacy.

Anti-parasitic drug discovery against Babesia microti by natural compounds: an extensive computational drug design approach.

Tick-borne Babesiosis is a parasitic infection caused by Babesia microti that can infect both animals and humans and may spread by tick, blood transfusions, and organ transplantation. The current therapeutic options for B. microti are limited, and drug resistance is a concern. This study proposes using computational drug design approaches to find and design an effective drug against B. microti. The study investigated the potentiality of nine natural compounds against the pathogenic human B. microti parasite and identified Vasicinone and Evodiamine as the most promising drugs. The ligand structures were optimized using density functional theory, molecular docking, molecular dynamics simulations, quantum mechanics such as HOMO-LUMO, drug-likeness and theoretical absorption, distribution, metabolism, excretion, and toxicity (ADMET), and pharmacokinetics characteristics performed. The results showed that Vasicinone (-8.6 kcal/mol and -7.8 kcal/mol) and Evodiamine (-8.7 kcal/mol and -8.5 kcal/mol) had the highest binding energy and anti-parasitic activity against B. microti lactate dehydrogenase and B. microti lactate dehydrogenase apo form. The strongest binding energy was reported by Vasicinone and Evodiamine; the compounds were evaluated through molecular dynamics simulation at 100 ns, and their stability when they form complexes with the targeted receptors was determined. Finally, the pkCSM web server is employed to predict the ADMET qualities of specific molecules, which can help prevent negative effects that arise from taking the treatment. The SwissADME web server is used to assess the Lipinski rule of five and drug-likeness properties including topological polar surface area and bioavailability. The Lipinski rule is used to estimate significant drug-likeness. The theoretical pharmacokinetics analysis and drug-likeness of the selected compounds are confirmed to be accepted by the Lipinski rule and have better ADMET features. Thus, to confirm their experimental value, these mentioned molecules should be suggested to carry out in wet lab, pre-clinical, and clinical levels.

Synergetic modulation on solvation structure and electrode interface to achieve lithium-ion batteries cycled at ultra-low temperature

The performance of rechargeable lithium-ion batteries (LIBs) in cold environments remains a challenge due to the insufficient ionic conductivity of electrolyte and lithium plating at graphite anodes. Herein, we demonstrate that the synergistic effect of ether-based electrolyte and niobium oxide with high intercalation potential can significantly improve the low-temperature charging/discharging performance of LIBs. Theoretical calculations and in-situ characterizations prove that the weak desolvation energy of electrolyte and the strong binding energy Li+-O bridging coordination synergistically accelerate the interfacial reaction kinetics. The full cells by coupling the niobium oxide anode with LiFePO4 cathode show 95.6% of the initial capacity after 500 cycles at −30 °C, and exhibit excellent rechargeability at −50 °C. This work verifies that the synergism of solvating power of solvent and Li+ intercalation behavior is crucial in low-temperature LIBs.

Computer-Aided Designing Peptide Inhibitors of Human Hematopoietic Prostaglandin D2 Synthase Combined Molecular Docking and Molecular Dynamics Simulation.

Human hematopoietic prostaglandin D2 synthase (HPGDS) is involved in the production of prostaglandin D2, which participates in various physiological processes, including inflammation, allergic reactions, and sleep regulation. Inhibitors of HPGDS have been investigated as potential anti-inflammatory agents. For the investigation of potent HPGDS inhibitors, we carried out a computational modeling study combining molecular docking and molecular dynamics simulation for selecting and virtual confirming the designed binders. We selected the structure of HPGDS (PDB ID: 2CVD) carrying its native inhibitor compound HQL as our research target. The random 5-mer peptide library was created by building the 3-D structure of random peptides using Rosetta Buildpeptide and performing conformational optimization. Molecular docking was carried out by accommodating the peptides into the location of their native binder and then conducting docking using FlexPepDock. The two peptides RMYYY and VMYMI, which display the lowest binding energy against HPGDS, were selected to perform a comparative study. The interaction of RMYYY and VMYMI against HPGDS was further confirmed using molecular dynamics simulation and aligned with its native binder, HQL. We show the selected binders to have stronger binding energy and more frequent interactions against HPGDS than HQL. In addition, we analyzed the solubility, hydrophobicity, charge, and bioactivity of the generated peptides, and we show that the selected strong binder may be further used as therapeutic drugs.

Computational screening and MM/GBSA-based MD simulation studies reveal the high binding potential of FDA-approved drugs against Cutibacterium acnes sialidase

Cutibacterium acnes is an opportunistic pathogen linked with acne vulgaris, affecting 80–90% of teenagers globally. On the leukocyte (WBCs) cell surface, the cell wall anchored sialidase in C. acnes virulence factor, catalysing the sialoconjugates into sialic acids and nutrients for C. acnes resulting in human skin inflammation. The clinical use of antibiotics for acne treatments has severe adverse effects, including microbial dysbiosis and resistance. Therefore, identifying inhibitors for primary virulence factors (Sialidase) was done using molecular docking of 1030 FDA-approved drugs. Initially, based on binding energies (ΔG), Naloxone (ZINC000000389747), Fenoldopam (ZINC000022116608), Labetalol (ZINC000000403010) and Thalitone (ZINC000000057255) were identified that showed high binding energies as −10.2, −10.1, −9.9 and −9.8 kcal/mol, respectively. In 2D analysis, these drugs also showed considerable structural conformer of hydrogen and hydrophobic interactions. Further, a 100 ns MD simulation study found the lowest deviation and fluctuations with various intermolecular interactions to stabilise the complexes. Out of 4, the Naloxone molecule showed robust, steady, and stable RMSD 0.23 ± 0.18 nm. Further, MMGBSA analysis supports MD results and found strong binding energy (ΔG) −29.71 ± 4.97 kcal/mol. In Comparative studies with Neu5Ac2en (native substrate) revealed naloxone has a higher affinity for sialidase. The PCA analysis showed that Naloxone and Thalitone were actively located on the active site, and other compounds were flickered. Our extensive computational and statistical report demonstrates that these FDA drugs can be validated as potential sialidase inhibitors. Communicated by Ramaswamy H. Sarma

Design and application of gel coagulation–spontaneous flotation integrated process in water treatment: “Clouds in water”

The gel coagulation–spontaneous flotation (GCSF) process designed in this paper mainly rely on dissolved gas in water rather than auxiliary gas equipment to achieve spontaneous flotation. Compared with the traditional coagulation-dissolved air flotation method, GCSF has more stable flotation efficiency and shorter operation cycle under conventional hydraulic conditions. In this study, the GCSF scheme was applied for surface water treatment, and its operating efficiency, mechanism of action, and environmental implications were explored systematically. The results illustrate that the dosage ratio of sodium alginate (SA) to aluminum sulfate (AS) should be controlled in the range of approximately 1.5:1–2.5:1, and SA should be added 15∼120 s before AS during the coagulation process. Under these conditions, the adsorption cross-linking between SA and Al3+ promoted the generation of gel flocs and effectively encapsulated the dissolved gasses, thereby achieving a stable spontaneous flotation process and 80%–95% removal of pollutants. The purification efficiency of GCSF was positively correlated with pH 4–9, which was attributed to the enhanced hydrophobicity of the chains of organic polymer groups. The residual SA and aluminum concentration in effluent were lower than 1 and 0.05 mg/L, respectively, which guarantee the ecological security of GCSF application. In addition, the results of density functional theory calculations revealed that -OH and -AlO6 in cross-linked flocs could adsorb dissolved oxygen synergistically, while -OH combined with oxygen had a stronger binding energy and stable adsorption.

DFT studies on exposure of sulfur impregnated and sulfur functionalized activated carbon to Hg0 vapors

For removal of poisonous vapor emissions such as mercury, it is necessary to select suitable materials based on an understanding of their properties and interactions with the vapor. As mercury has a high affinity towards sulfur, it’s adsorption using sulfur-impregnated activated carbon was explored in this study. The impregnation of sulfur on activated carbon followed by the adsorption of Hg0 vapors was computationally investigated using DFT simulations. Sulfur adsorption was investigated on activated carbon with armchair edge, zigzag edge, and graphene surface. Sulfur adsorption was investigated on activated carbon with edge functional groups such as hydroxyl and carboxylic acid. Activated carbon with edge functional groups such as sulfonic acid, sulfenic acid, and sulfinic acid was further investigated for the adsorption of Hg0 vapors. Among the edge functional groups on the activated carbon, the hydroxyl group was most favored for sulfur adsorption and, subsequently, Hg0 vapors. This was quantified in terms of shortest bond lengths, strongest binding energies, and maximum charge transfer. Among the sulfur-containing functional groups on activated carbon, sulfenic acid was the most favored for the adsorption of Hg0 vapors. Transition state calculations were carried out, and a reaction pathway was proposed for the adsorption of Hg0 on sulfur-impregnated activated carbon.

Network Pharmacology and Molecular Docking Reveal the Mechanism of Corydalis saxicola Bunting Total Alkaloids in Treating Radiation-Induced Oral Mucositis.

The study aims to explore the effect and mechanism of total alkaloids of Corydalis saxicola Bunting (CSBTA) in the treatment of radiation induced oral mucositis (RIOM) through network pharmacology and molecular docking. The components and corresponding targets of Corydalis saxicola Bunting were screened by literature review. RIOM related targets were obtained in GeneCards. Cytoscape software was used to construct the component-target-pathway network. Protein-Protein Interaction (PPI) networks was constructed using String database. GO and KEGG enrichment analyses were performed by Metascape. AutoDock Vina 4.2 software was used for molecular docking. There were 23 components related to the treatment of RIOM, and 61 corresponding targets. Through Cytoscape and PPI analysis, 15 core targets including AKT1, EGFR, JUN and SRC were identified. GO functional analysis indicated that CSBTA might play a role through kinase binding and protein kinase activation. KEGG pathway analysis showed that the core targets of CSBTA were mainly focused on cancer and reactive oxygen species (ROS) pathway. The results of molecular docking showed that CSBTA had strong binding energy with target protein including SRC, AKT and EGFR. The study demonstrated a potential mechanism of CSBTA against RIOM, laying the groundwork for future application of Corydalis saxicola Bunting for RIOM.

Theoretical study of the electronic and optical properties of ZnO/MgO rock salt superlattices

An analysis of some electronic and optical properties of rock salt (RS) ZnO/MgO superlattices related to potential applications in optoelectronics and electronics is carried out.In order to find possible light emission mechanisms, the electronic band structure, projected and k-resolved projected density of states and optical parameters such as the refractive index, reflection and absorption coefficients are calculated.We show that the bandgap of the RS ZnO/MgO superlattice is indirect for all considered thicknesses of quantum wells and barriers. Despite the indirect character of the bandgap, other features of the studied superlattice, such as the flat character of the top of the valence band and the bottom of the conduction band, combined with strong electron-phonon coupling and high exciton binding energy, may indicate the possibility of light emission similar to that in hexagonal BN.

Investigation of cytotoxic properties of some isoindole-related compounds bearing silyl and azide groups with in vitro and in silico studies

This study aims to evaluate the synthesis of isoindole-1,3-dione analogues and their cytotoxic potential. A549 and HeLa cells exposed to 250–100–50–25 µM doses of each derivative were incubated for 24, 48, and 72 h. The cytotoxicity of the isoindole-1,3-dione derivatives was analyzed using the cell growth inhibition assay and the cell membrane damage test. (3aR,5R,6R,7aS)-5-Azido-2-benzyl-6-hydroxyhexahydro-1H-isoindole-1,3(2H)-dione (1d), (3aR,5R,6R,7aS)-5-azido-6-((tert-butyldiphenylsilyl)oxy)-2-ethylhexahydro-1H-isoindole-1,3(2H)-dione (2a), and (3aR,5R,6R,7aS)-5-azido-6-((tert-butyldiphenylsilyl)oxy)-2-methylhexahydro-1H-isoindole-1,3(2H)-dione (2b) compounds inhibited the growth of the A549 and HeLa cells caused membrane damage and exhibited a dose-dependent cytotoxic effect on lung and cervical carcinoma cells. The effect of tert-butyldiphenylsilyl (TBDPS) groups on cytotoxicity was observed in compounds 2a and 2b, but not in the other compounds. Considering the effect of groups attached to the nitrogen atom, the best activity was exhibited in 2b molecule to which the methyl group is attached. Additionally, the interactions of compounds (3aR,5R,6R,7aS)-5-azido-6-hydroxy-2-methylhexahydro-1H-isoindole-1,3(2H)-dione (1b), 1d, 2a and 2b with mammalian rapamycin target, human ribosomal S6 kinase 1 and human epidermal growth factor receptor were investigated by molecular docking studies, . According to the docking results, 2a and 2b compounds containing a TBDPS group have stronger binding energies than 1b and 1d compounds against all target receptors.

Synthesis, glycosidase inhibitory activity and computational studies of dideoxymethylnojirimycin and its derivatives

We report here the synthesis and biological evaluation of dideoxynojirimycin and its analogs and their functional effect on glucosidase enzyme inhibition against α-glucosidase(yeast), α-galactosidase and β-galactosidase (kluyveromyces lactis). All the compounds significantly inhibited the α-glucosidase(yeast) activity when compared to DNJ and shown strong inhibition against β-galactosidase (kluyveromyces lactis) when compared to DNJ. The molecular docking studies also reveals that these compounds showing strong ligand binding energies against yeast-ɑ-glucosidase- I, yeast β-galactosidase and human lysosomal acid–ɑ-glucosidase. Interestingly the analogues having N-H, N-alkyl and N-benzyl group along with ethyl group significantly inhibited the β-galactosidase activity when compared to DNJ. The in-silico studies are in correlation with invitro activity data; therefore, this study will be useful to develop further glycosidase inhibitors.

Interaction-driven transport of dark excitons in 2D semiconductors with phonon-mediated optical readout

The growing field of quantum information technology requires propagation of information over long distances with efficient readout mechanisms. Excitonic quantum fluids have emerged as a powerful platform for this task due to their straightforward electro-optical conversion. In two-dimensional transition metal dichalcogenides, the coupling between spin and valley provides exciting opportunities for harnessing, manipulating, and storing bits of information. However, the large inhomogeneity of single layers cannot be overcome by the properties of bright excitons, hindering spin-valley transport. Nonetheless, the rich band structure supports dark excitonic states with strong binding energy and longer lifetime, ideally suited for long-range transport. Here we show that dark excitons can diffuse over several micrometers and prove that this repulsion-driven propagation is robust across non-uniform samples. The long-range propagation of dark states with an optical readout mediated by chiral phonons provides a new concept of excitonic devices for applications in both classical and quantum information technology.

Bioactive compounds derived from marine source: a potential immunotherapy treatment

Immunotherapy using checkpoint inhibitors blocks the checkpoint proteins (programmed cell death receptor-1; PD-1) from binding with their corresponding ligands (programmed cell death receptor ligand-1; PD-L1) to regulate cell signaling pathways. The marine environment holds a huge source of small molecules that are understudied which can be developed as an inhibitor. Hence, this study investigated the inhibitory effect of 19 algae-derived small molecules against PD-L1 by using molecular docking, absorption, distribution, metabolism, and elimination (ADME) properties and molecular dynamics simulations (MDS). The molecular docking revealed that the binding energy of the six best compounds ranges from −11.1 to −9.1 kcal/mol. Fucoxanthinol, in particular, has the strongest binding energy at −11.1 kcal/mol with three hydrogen bonds (ASN:63A, GLN:66A, and ASP:122A). Meanwhile, the MDS demonstrated that the ligands were strongly bound to the protein, indicating the stability of the complexes. In summary, the identified compounds are potential PD-L1 inhibitors in immunotherapy. Communicated by Ramaswamy H. Sarma

Giant excitonic effects in vacancy-ordered double perovskites

Using first-principles GW plus Bethe-Salpeter equation calculations, we identify anomalously strong excitonic effects in several vacancy-ordered double perovskites Cs2MX6 (M = Ti, Zr; X = I, Br). Giant exciton binding energies about 1 eV are found in these moderate-gap, inorganic bulk semiconductors, pushing the limit of our understanding of electron-hole (e-h) interaction and exciton formation in solids. Not only are the exciton binding energies extremely large compared with any other moderate-gap bulk semiconductors, but they are also larger than typical 2D semiconductors with comparable quasiparticle gaps. Our calculated lowest bright exciton energy agrees well with the experimental optical band gap. The low-energy excitons closely resemble the Frenkel excitons in molecular crystals, as they are highly localized in a single [MX6]2- octahedron and extended in the reciprocal space. The weak dielectric screening effects and the nearly flat frontier electronic bands, which are derived from the weakly bonded [MX6]2- units, together explain the significant excitonic effects. Spin-orbit coupling effects play a crucial role in red-shifting the lowest bright exciton by mixing up spin-singlet and spin-triplet excitons, while exciton-phonon coupling effects have minor impacts on the strong exciton binding energies.

Co-loading of doxorubicin and gemcitabine on folic acid functionalized carbon nanotubes; a molecular dynamics simulation study

Nanomedicine based drug delivery design was performed in this study for two drugs of small-molecule API by advanced computational method. The co-loading of doxorubicin (DOX) and gemcitabine (GEM) on pristine and functionalized carbon nanotubes (CNTs) was investigated by molecular dynamics (MD) simulation. The functionalization of CNTs was done with carboxyl (CNT-COO) and folic acid groups (CNT-FA). Different ratios of DOX and GEM were simulated. Functionalized nanotubes have stronger binding energy with drugs due to electrostatic interactions. CNT-FA showed the highest amount of GEM encapsulation. In the co-loading of DOX and GAM, GEM tends to encapsulate inside the CNT because it has a weaker dipole moment. Encapsulation of drugs was investigated by radial function analysis. The results showed that the CNT-DA in a molar ratio of 1:2 (DOX:GEM) is the best selection for co-loading of DOX and GEM.

Identification of novel inhibitors for trigger factor (TF) of M. tb: an in silico investigation

Trigger factor, as a chaperone protein, is required for survival of Mycobacterium tuberculosis (M.tb) in a stressed environment. This protein interacts with various partners in both the pre- and the post-translation processes, yet the crystal structures of the M.tb trigger factor remain unresolved. In this study, we developed a homology model of M.tb trigger factor to facilitate the discovery and design of inhibitors. To validate the model, we employed several methodologies, including Ramachandran plot and molecular dynamics simulations. The simulations showed a stable trajectory, indicating the accuracy of the model. The active site of M.tb Trigger Factor was identified based on site scores, and virtual screening of over 70,000 compounds led to the identification of two potential hits: HTS02984 (ethyl 2-(3-(4-fluorophenyl)ureido)-6-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate) and S06856 ((E)-N-(4-((2-(4-(tert-butyl)benzoyl)hydrazono)methyl)phenyl) acetamide). These compounds showed strong binding affinity and energy scores, and their chemical descriptors were evaluated. Our study provides a reliable computational model for M.tb Trigger Factor and identifies two potential inhibitors for this crucial protein, which could aid in the development of novel therapies against tuberculosis. Communicated by Ramaswamy H. Sarma

Design and synthesis of multi-functional small-molecule based inhibitors of amyloid-β aggregation: Molecular modeling and in vitro evaluation.

Amyloid-β1-42 (Aβ42) peptide aggregate formation in the brain plays a crucial role in the onset and progression of Alzheimer's disease. According to published research, the Aβ monomer's amino acid residues KLVFF (16-20) self-associate to create antiparallel β-sheet fibrils. Small compounds can prevent self-assembly and destroy Aβ fibrils by attaching to the Aβ16-20 regions of Aβ42. To enhance biological characteristics and binding affinity to the amyloid beta peptide, β-sheet breaker small molecules can be developed and modified with various scaffolds. In the current study, a novel series of 2,3-disubstitutedbenzofuran derivatives was designed and created by fusing the benzofuran core of a known iron chelator, neuroprotective, and neurorestorative agent, like VK-28, with a motif found in the structure of a known muscarinic inhibitor and amyloid binding agent, like SKF-64346. Measurements of the binding affinity and in vitro aggregation inhibition of the Aβ42 peptide were made using the thioflavin T (ThT) test. Using AutoDock 4.2 software, molecular docking studies of the synthesized compounds were performed on the monomer and fibril structures of amyloid beta peptide. The compounds 8a-8g exhibited strong binding energy and affinity to Aβ fibrils as well as a 50%-67% reduction of the growth of Aβ aggregation. Finally, the positive traits of our recently synthesized compounds make them excellent candidates for additional in vivo testing as a "β-sheet breaking agent."

Evaluation of The Anticancer Activity of Hydroxyxanthones Against Human Liver Carcinoma Cell Line

Nowadays, cancer is one of the most fatal diseases in developed and developing countries. Therefore, it is an urgent need to find more effective anticancer drugs among the recent commercially available standard drugs. Xanthone derivatives have been researched as anticancer drugs due to their ease of synthesis and structure modification, as well as their excellent anticancer activity. In this work, the in vitro anticancer activity of hydroxyxanthones against the human liver carcinoma cell line (HepG2) was evaluated. Among the twenty-two hydroxyxanthones, 1,3,6,8-tetrahydroxyxanthone was found as the most active anticancer agent with an IC50 value of 9.18 μM, which was better than doxorubicin as the standard drug. From the molecular docking studies against topoisomeraseIIα and two c-KIT protein kinases, 1,3,6,8-tetrahydroxyxanthone yielded strong binding energy in a range of -25.48 to -30.42 kJ/mol. The 1,3,6,8-tetrahydroxyxanthone could bind on the active site of these protein receptors through hydrogen bonds with key amino acid residues (Glu640, Cys673, Gln767, Met769, Asp810, and Asp831), as well as nitrogen bases (Adenine12 and Guanine13), thus leading to the death of HepG2 cancer cells through the apoptosis mechanism.