Synthesis, XRD, Hirshfeld surface analysis, ESP, HOMO-LUMO, Quantum chemical modeling and Anticancer activity of di(p-methyl benzyl)(dibromo)(1,10-phenanthroline) tin(IV) complex

Synthesis, solvent role, absorption and emission studies of cytosine derivative

The (E)-4-((4-hydroxy-3-methoxy-5-nitrobenzylidene) amino) pyrimidin-2(1H)-one (C5NV) was synthesized from cytosine and 5-nitrovanilline by simple straightforward condensation reaction. The structural characteristics of the compound was determined and optimized by WB97XD/cc-pVDZ basis set. The vibrational frequencies were computed and subsequently compared to the experimental frequencies. We investiated the electronic properties of the synthesized compound in gas and solvent phases using the time-dependent density functional theory (TD-DFT) approach, and compared them to experimental values. The fluorescence study showed three different wavelengths indicating the nature of the optical material properties. Frontier molecular orbital (FMO) and molecular electrostatic potential (MEP) analyses were conducted for the title compound, and electron localized functions (ELF) and localized orbital locators (LOL) were used to identify the orbital positions of localized and delocalized atoms. Non-covalent interactions (H-bond interactions) were investigated using reduced density gradients (RDGs). The objective of the study was to determine the physical, chemical, and biological properties of the C5NV. The molecular docking study was conducted between C5NV and 2XNF protein, its lowest binding energy score is -7.92 kcal/mol.

Synthesis, topology, molecular docking and dynamics studies of o-phenylenediamine derivative

The N, N'-(1,2-phenylene) bis (1- (4- chlorophenyl) methanimine) (CS4) was synthesized and characterized by infrared (IR), absorption (UV-vis) and NMR (1H and 13C) spectral analyses. The structural parameters, vibrational frequencies, potential energy and the distribution analysis (PED) were calculated by using DFT with the basis set of B3LYP/cc-pVDZ and these spectral values were compared to the experimental values. HOMO and LUMO studied were performed in order to understand the stability and biological activity of the compound. The most reactive sites on the compound were investigated by utilizing MEP energy surface and Fukui function descriptor with the natural population analysis (NPA) of the charges. The study of the natural bond orbitals (NBO) reveals the delocalization of the intramolecular interaction of the charges in the compound. Additionally, topological investigations (ELF, LOL), determination of thermodynamic parameters and noncovalent interaction (NCI) study by using topology (RDG) analysis were also carried out. Finally, the molecular docking and molecular dynamics simulations was carried out by examining against glycosylphosphatidylinositol phospholipase D inhibitor receptor for distinct protein targets (3MZG).Communicated by Ramaswamy H. Sarma.

Identification of IL-2 inducible tyrosine kinase inhibitors by quantum mechanics and ligand based virtual screening approaches

Interleukin-2-inducible T-cell kinase (ITK) is a crucial intracellular signaling mediator in normal and malignant T-cells and natural killer cells. Selective inhibition of ITK might be useful for treating a variety of disorders including; autoimmune, inflammatory, and neoplastic disorders. Over the past two decades, the clinical management of ITK inhibitors has progressed dramatically. So far, specific inhibitor with no off-target effects against ITK is available. Herein, we aim to discover potential virtual hits to fasten the process of drug design and development against ITK. In this regard, the key chemical characteristics of ITK inhibitors were identified using ligand-based pharmacophore modeling. The validated pharmacophore comprises one hydrogen bond donor and three hydrogen bond acceptors and was utilized as a 3D query in virtual screening using ZINC, Covalent, and in-house databases. A total of 12 hit compounds were chosen on the basis of their critical interactions with the significant amino acids of ITK. The orbital energies such as HOMO and LUMO of the hit compounds were calculated to evaluate the inhibitor's potencies. Further, molecular dynamics simulation demonstrated the stability of ITK upon binding of selected virtual hits. Binding energy using the MMGBSA method showed the potential binding affinity of all the hits with ITK. The research identifies key chemical characteristics with geometric restrictions that lead to ITK inhibition.Communicated by Ramaswamy H. Sarma.

Synthesis, characterization and discovery of multiple anticancer mechanisms of dibutyltin complexes based on salen-like ligands

A series of novel dibutyltin complexes based on salen-like ligands (S01-S03) were synthesized and characterized using ultraviolet-visible spectra，infrared spectra, 1H, 13C, and 119Sn nuclear magnetic resonance, high-resolution mass spectrometry, X-ray crystallography, and thermogravimetric analysis. Complex S03 had excellent anticancer activity in vitro (IC50 = 1.5 ± 0.2 μM in CAL-27 cell lines), which highly activated ROS expression levels and induced apoptosis and cell cycle arrest at the G2/M phase. Interestingly, complex S03 induced cancer cell death through multiple mechanisms (mitochondrial pathway, ER-stress pathway, and DNA damage pathway). This study reveals new mechanisms of organotin complexes and provides new insights into the development of organotin metal complexes as anticancer drugs in the future, and compounds with multiple anticancer mechanisms may be a new strategy for delaying or overcoming drug resistance to chemotherapy and target therapy.

Antimicrobial activity prediction, inter- and intramolecular charge transfer investigation, reactivity analysis and molecular docking studies of adenine derivatives

The utilization of the density functional theory (DFT) methodology has developed as a highly efficient method for investigating molecular structure and vibrational spectra, and it is increasingly being employed in various applications relating to biological systems. This study focuses on conducting investigations, both experimental and computed, to analyze the molecular structure, electronic properties and features of (E)-4-(((9H-purin-6-yl)imino)methyl)-2-methoxyphenol (ANVA). The expression ANVA should be rewritten as follows: the compound is a derivative of adenine (primary amine), specifically a vanillin (aldehyde). The present study reports the synthesis, characterization, DFT, docking and antimicrobial activity of ANVA. The optimization of the molecular structure was conducted, and the determination of its structural features was performed using DFT with the B3LYP/cc-pVDZ method. The vibrational assignments were determined in detail by analyzing the potential energy distribution. A strong correlation was observed between the spectra that were observed and the spectra that were calculated. The calculation of intramolecular charge transfer was performed using natural bond orbital analysis. In addition, several computational methods were employed, including highest occupied molecular orbital-least unoccupied molecular orbital analysis, molecular electrostatic potential calculations, non-linear optical, reduced density gradient, localization orbital locator and electron localization function analysis. This paper examines the present use of adenine derivatives in combatting bacterial and fungal infections, as well as the inclusion of spectral and quantum chemical calculations in the discussion.Communicated by Ramaswamy H. Sarma.

New flavone-based arylamides as potential V600E-BRAF inhibitors: Molecular docking, DFT, and pharmacokinetic properties

Objectives

The V600E-BRAF protein kinase is an attractive and essential therapeutic target in melanoma and other tumors. However, because of its resistance to the known inhibitors and side effects of some identified inhibitors, new potent inhibitors need to be identified.

Methods

In the present work, in silico strategies such as the molecular docking simulation, DFT (Density-Functional-Theory) computations, and pharmacokinetic evaluation were used to determine potential V600E-BRAF inhibitors from a set of 31 synthesized novel flavone-based arylamides.

Results

The docking result demonstrated that four compounds (10, 11, 28, and 31) had acceptable docking scores (MolDock score of -167.523 kcal mol^-1, -158.168 kcal mol^-1, -160.581 kcal mol^-1,-162.302 kcal mol^-1, and a Rerank score of -124.365, -129.365, -135.878 and -117.081, respectively) appeared as most active and potent V600E-BRAF inhibitors that topped vemurafenib (-158.139 and -118.607 kcal mol^-1). The appearance of H-bonds and hydrophobic interactions with essential residues for V600E-BRAF proved the high stability of these complexes. The energy for the frontier molecular orbitals such as HOMO, LUMO, energy gap, and other reactivity parameters was computed using DFT. The frontier molecular-orbital surfaces and electrostatic potentials (EPs) were investigated to demonstrate the charge-density distributions that might be linked to anticancer activity. Similarly, the chosen compounds revealed superior pharmacological properties according to the drug-likeness rules (bioavailability) and pharmacokinetic properties.

Conclusion

The chosen compounds were recognized as potent V600E-BRAF inhibitors with superior pharmacokinetic properties and could be promising cancer drug candidates.

A novel cobalt(ii) acetate complex bearing lutidine ligand: a promising electrocatalyst for oxygen evolution reaction

Developing cost-effective electrocatalysts using earth-abundant metal as an alternative to expensive precious metal catalyst remains a key challenge for researchers. Several strategies are being researched/tested for making low-cost transition metal complexes with controlled electron-density and coordination flexibility around the metal center to enhance their catalytic activity. Herein, we report a novel lutidine coordinated cobalt(ii) acetate complex [(3,5-lutidine)2Co(OAc)2(H2O)2] (1) as a promising electrocatalyst for oxygen evolution reaction (OER). Complex 1 was characterized by FT-IR, elemental analysis, and single crystal X-ray diffraction data. The structure optimization of complex 1 was also done using DFT calculation and the obtained geometrical parameters were found to be in good agreement with the parameters obtained from the solid state structure obtained through single crystal X-ray diffraction data. Further, the molecular electrostatic potential (MEP) maps analysis of complex 1 observed electron rich centers that were found to be in agreement with the solid-state structure. It was understood that the coordination of lutidine as a Lewis base and acetate moiety as a flexible ligand will provide more coordination flexibility around the metal center to facilitate the catalytic reaction. Further, the electron rich centers around metal center will also support the enhancement of their catalytic activity. Complex 1 shows impressive OER activity, even better than the state-of-the-art IrO2 catalyst, in terms of turnover frequency (TOF: 0.05) and onset potential (1.50 V vs. RHE). The TOF for complex 1 is two and half times higher, while the onset potential is ca. 20 mV lower, than the benchmark IrO2 catalyst studied under identical conditions.