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Cefoperazone belongs to the third generation of cephalosporin antibiotics. It is accumulated in water due to its overuse and causes bacterial, environmental, and health issues. In this work, the efficiency of photocatalytic degradation of cefoperazone was studied using different types of radiation (simulated solar, UV, and LED) in the presence of different nanomaterials (ZnO and TiO2). First, the photolytic degradation of cefoperazone was examined, where UV radiation showed as most effective for cefoperazone degradation, wherein 29.5% of cefoperazone was degraded after 60 min. Photocatalysis in the presence of TiO2 leads to complete removal of cefoperazone after 30 min, while the use of ZnO leads to complete photocatalytic degradation of cefoperazone after 20 min using UV radiation. Simulated solar and LED radiation showed slightly lower efficiencies. When TiO2 was applied, the removal efficiency was around 60%, while approximately 70% of cefoperazone was degraded when ZnO was used.

Developing modifiable natural products those having antiviral activities against SARS-CoV-2 is a key research area which is popular in current scenario of COVID pandemic. A diaryl heptanoid curcumin and its derivatives are already presenting promising candidates for anti-viral drug development. We have synthesized single crystals of a dimethylamino derivative of natural curcumin and structural characterization was done by single crystal XRD analysis. Using steady-state absorption and emission spectra and guided by complimentary ab initio calculations, we unraveled the solvent effects on the photophysical properties of the dimethyl amino curcumin derivative. Chemical reactivity of the compound has investigated using frontier molecular orbitals and molecular electrostatic potential surface. High stability of the curcumin derivative in water environment has evaluated by Radial Distributions Functions (RDF) calculated via Molecular Dynamics (MD) simulations. The inhibitory activity of the title compound was evaluated by in silico methods and the stability of the protein-ligand complexes were studied using Molecular Dynamics simulations and MM-PBSA analysis. With this detailed study, we hope to motivate scientific community to develop new curcumin derivatives against SARS-CoV-2 virus.

In this work we report spectroscopic characterization and reactivity study by density functional theory (DFT) and molecular dynamics (MD) simulations of two quinoline derivatives. Collected computational results for the two new derivatives have been compared with the pristine quinoline in order to investigate the consequences of modifications by introduction of chlorine atoms and methyl and OH groups. Potential energy distribution (PED) analysis has been performed in order to assign principal vibrational numbers. DFT calculations have been used to obtain global and local quantum-molecular descriptors including frontier molecular orbitals, charge distribution by molecular electrostatic potential (MEP) surface, average local ionization energy (ALIE) surface, and Fukui functions. Natural bond order (NBO) analysis has been performed in order to investigate hyper-conjugative properties. To investigate sensitivity towards autoxidation and hydrolysis we have calculated bond dissociation energies (BDE) and radial distribution functions (RDF). Molecular docking study has also been performed in order to initially assess the potential of target molecules to bind with dehydrogenase inhibitor and these quinoline derivatives can be a lead compounds for developing new anti-malarial drug. Keywords: Quinoline, DFT, ALIE, BDE, RDF, Molecular docking

We present the atomistica.online, a web application for generating input files for the ORCA molecular modelling package. atomistica.online is entirely made with the Anvil platform, which allows the development of web applications using only Python programming language. ORCA is one of the most, if not the most, powerful molecular modelling tools covering a wide range of possibilities for atomistic calculations on molecules. Speed, ease of installation and use, and clear and intuitive syntax for input files are some of ORCA's characteristics that make it one of the most cited modelling tools in the last several years. Nevertheless, although tools for generating input files for ORCA exist, they are not available as online applications. In this work, we demonstrate how the combination of Python programming language and the Anvil platform makes the development of scientific web applications available to all scientists. All tools within atomistica.online are freely available at the project's official website–https://atomistica.online.

Photocatalytic activity of titania–based photocatalysts doped with 1% La has been tested in UVA radiation-induced degradation of two β-blockers – metoprolol tartrate (MET) and propranolol hydrochloride (PRO). Photocatalysts have been synthesized by sol–gel process followed by calcination at various temperatures in the range of 450–750 °C. The great impact of calcination temperature on the structural, compositional and morphological properties of prepared catalysts has been revealed by XRPD, SEM, BET and Raman scattering measurements. Doped catalysts calcined at 450–650 °C, with dominant anatase phase and developed mesoporous structure, have displayed higher photocatalytic performance than much less porous samples calcined at 700–750 °C, with sodium hexatitanate as dominant phase. Also, La-doped anatase sample has shown higher efficiency in degradation of MET and PRO in comparison with the efficiency of undoped TiO2 nanopowders calcined at same temperatures. The quenching effects of various scavengers suggest that the major role in degradation of MET may be attributed to reactive radicals, whereas photogenerated holes are mainly responsible for degradation of PRO. Applying density functional theory (DFT) calculations, we analyzed fundamental structural and electronic properties (total and polar surface areas, frontier molecular orbitals, optoelectronic properties and average local ionization energy surfaces) of MET and PRO molecules, which are of significance for the understanding of more effective degradation of PRO in comparison with MET. Keywords: β-blocker, Photocatalysis, Anatase, La-doping, Density functional theory (DFT), Average local ionization energy (ALIE)

A new titanium/molybdenum/mixed-oxides (TMO) contact-type heterojunction photocatalyst was prepared by a simple, low-cost, and environmentally-friendly mixing-calcination solid-state method. A microstructural investigation by scanning electron microscopy (SEM) showsirregularly shaped agglomerated morphology of TMO that consists of firmly connected globular TiO2 and rod-like MoO3 particles. The detailed structure and optical bandgap investigation by X-ray diffraction, Raman, and UV-Vis spectroscopy revealed the TMO’s composition of ~37 wt.% rutile TiO2, ~25 wt.% of anatase TiO2, and ~38 wt.% of molybdite MoO3 phase and an absorption threshold of around 380 nm, which implies more probability of desirable higher visible light absorption. The removal efficiency of pesticides quinmerac (QUI) and tembotrione (TEM), and pharmaceuticals metoprolol (MET), amitriptyline (AMI), ciprofloxacin (CIP),and ceftriaxone (CEF) from water in the presence of starting pure TiO2, MoO3, and prepared TMO were investigated under different pH values and UV irradiation/simulated sunlight (SS). Each starting metal-oxide precursors and prepared TMO showed a different affinity for adsorption of tested pesticides and pharmaceuticals, and, in general, better photocatalytic degradation efficiency under UV irradiation than under simulated sunlight. The highest photocatalytic degradation efficiency under UV irradiation was 81.6% for TEM using TMO, using TiO2 was 65.0% for AMI, and using MoO3 was 79.3% for CEF after 135 min. However, TMO showed a very high synergic adsorption/photocatalytic under-SS efficiency in the removal of CIP of almost 80% and under UV irradiation of 90% CIP removal after 75 min. The toxicity of catalysts, starting compounds, and their intermediates formed during the removal process was assessed using a rat hepatoma cell line (H-4-II-E). The highest hepatotoxic effects were obtained by using UV irradiated QUI and MET suspension with TMO for up to 60 min.

© 2021 Elsevier B.V.A set of molecular descriptors have been calculated and used in order to identify the most reactive parts of bioactive molecules, brucine (BRU) and colchicine (COL). Comparison of various physico-chemical properties has been performed in order to investigate stability. Besides global and local reactive parameters, attention has been paid to the autoxidation properties and reactivity with water molecules. Molecular Dynamics (MD) simulations and docking results show that BRU and COL bound D-lactate dehydrogenase enzyme are less fluctuating and more stable than the apo protein. To reveal the autoxidation and reactivity with water molecules Density Functional Theory (DFT) simulation has been carried out for the interactions and charge transfer mechanism of water molecules on different sites of bio-molecules, BRU and COL. This may help to further understand and identify the most active parts of the bio-molecules, BRU and COL. We have presented various interaction parameters, e.g., adsorption energy, molecular distance, charge transfer and orbital interactions. The sites with higher adsorption energy and charge transfer signify better reactivity with water.

Anthracenes are aromatic compounds with flexible structure and reactivity which are of great interest to theoretical and experimental chemists. Theoretical investigations of 1,4-dihydroxy-5,8-bis[2-(2-hydroxyethylamino)ethylamino]anthracene-9,10-dione (Mitoxantrone) (DDEA) based on density functional theory, molecular dynamics and adsorption on fullerene are reported in the present research. The suitable situation for adsorption with fullerene (C60) is the cyclohex-2-ene-1,4-dione ring of DDEA. Selected quantum-molecular descriptors have been calculated to predict the most reactive sites of the DDEA molecule. Interactions of DDEA with water have been studied using MD simulations. MD simulations were also used to study solubility parameter, a significant quantity for the development of pharmaceutical formulations. The affinity of DDEA on human dihydrofolate reductase and deoxyuridine triphosphatase enzymes was investigated by MD simulation of the protein–ligand complex obtained by molecular docking study. Communicated by Ramaswamy H. Sarma.

Spectroscopic analysis of 1-(2-fluorophenyl)-3-[3-(trifluoromethyl)phenyl]thiourea (FPTT) is reported. Experimental and theoretical analyses of FPTT, with molecular dynamics (MD) simulations, are reported for finding different parameters like identification of suitable excipients, interactions with water, and sensitivity towards autoxidation. Molecular dynamics and docking show that FPTT can act as a potential inhibitor for new drug. Additionally, local reactivity, interactivity with water, and compatibility of FPTT molecule with frequently used excipients have been studied by combined application of density functional theory (DFT) and MD simulations. Analysis of local reactivity has been performed based on selected fundamental quantum-molecular descriptors, while interactivity with water was studied by calculations of radial distribution functions (RDFs). Compatibility with excipients has been assessed through calculations of solubility parameters, applying MD simulations. Graphical abstract Reactive sites identified.

Amiloride (AMI) is a representative of diuretics. Among other purposes, it is utilized for high blood pressure or swelling induced by heart failure. While it is identified as one of the safest medicines available, it is also listed in the World Anti-doping Agency’s list of substances banned in sport, because it is considered a masking agent. Since it has been abused in sports, methods have been developed to be able to detect it during doping controls. We have computationally investigated selected structural and reactive properties of the AMI molecule in this work, employing density functional theory calculations.

© 2019 Elsevier B.V. Experimental and theoretical spectroscopic studies were performed for the 7, 8-benzocoumarin-4-acetic acid (7BAA). The research work was performed in two levels. In the first level, experimental FT-IR, FT-Raman and UV–Vis spectral data were recorded. In the next level, the theoretical computations have been conducted from DFT∖B3LYP∖6-311++G (d, p) basis level. Initially theoretical geometrical parameters were obtained and compared with the related experimental parameters. The computed FT-IR and FT-Raman frequencies collected from same basis level and compared with experimental data. The important wavenumber assignments were achieved on the PED of individual vibrational mode. Theoretical (TD-DFT) and experimental UV–Vis absorption wavelengths (λ) were compared with each other. The FMO, NBO, MEP analyses were performed. In addition, molecular dynamic (MD) simulations, molecular docking and selected optoelectronic properties have been studied.

© 2019, © 2019 Taylor & Francis Group, LLC. Theoretical calculations at the B3LYP/CC-pVDZ level were used to find the IR, Raman, VCD, and various molecular properties of a terphenyl derivative. Experimental and theoretical spectra agree within their respective limits. Partial density of states shows which parts of the molecules have the most important contribution to the FMO. Fluorine, sulfur, oxygen, and nitrogen atoms have practically insignificant contribution to the HOMO. Time dependent DFT calculations were used to study excitations, while natural transition orbitals were used to study the charge transfer in the strongest excitation. The experimentally observed FTIR modes are compared with calculated wavenumbers. Natural bond orbital analysis gives the idea about stability of molecules. MD simulations are used for calculating solubility parameters. Autoxidation and bond dissociation studies indicate stability of the compound. The docked ligands form secure complexes with the receptor methionyl-tRNA synthetase which indicates new anti-protozoan drugs.

© 2018 Elsevier B.V. The synthesis, spectroscopic characterization, reactivity study and evaluation of antioxidant and α-glucosidase inhibitory activities of two Schiff bases containing 1,2,4-triazole and pyrazole rings namely: 4-((4-methoxybenzylidene)amino)-5-(5-methyl-1H-pyrazol-3-yl)-4H-1,2,4-triazole-3-thiol 3a and 4-((4-(dimethylamino)benzylidene)amino)-5-(5-methyl-1H-pyrazol-3-yl)-4H-1,2,4-triazole-3-thiol 3b were reported in the present work. Reactive properties of the two compounds have been investigated by means of combination of DFT calculations, molecular dynamics (MD) simulations and drug likeness parameters, followed by calculations of molecular electrostatic potential (MEP) and average local ionization energy (ALIE) values. Additionally, the sensitivity of 3a and 3b towards the autoxidation mechanism has been investigated by the concept of bond dissociation energies for hydrogen abstraction (H-BDE). α-glucosidase inhibition assay revealed that the two compounds displayed significant inhibitory potentials in terms of relative IC50 values as compared to that of the reference drug (Acarbose). In addition, the antioxidant activity of the synthesized compounds were determined in vitro by 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and ferric reducing antioxidant power (FRAP) methods. Results revealed that the compound 3a is a potent antioxidant agent.

© 2018 Elsevier B.V. The present work describes the synthesis and characterization of a novel pyrene-naphthalene based Schiff base ligand and its copper complexes. The ligand was synthesized by reacting 1-Pyrenecarboxaldehyde and 1,8-Diaminonaphthalene in 2:1 M ratio. The resulting Schiff base ligand, (N1E,N8E)-N1,N8-bis(pyren-1-ylmethylene)naphthalene-1,8-diamine (BPND) was characterized by NMR ( 1 H and 13 C), FT-IR and ESI-HRMS techniques. Further, BPND was used to synthesize two Cu(II) complexes (1 and 2) in 2:1 (ligand:metal) and 1:1:1 (ligand:metal:8-hyroxyquinoline) molar ratio, and characterized using electronic absorption, fluorescence spectroscopy, in addition to aforementioned spectroscopic techniques. DFT calculations have been used in order to obtain information on quantum-molecular descriptors reflecting the local reactivity properties. DFT calculations encompassed geometrical optimizations of title molecules and calculations of molecular electrostatic potential (MEP), average local ionization energies (ALIE) and atomic Fukui indices.

© 2018 The spectroscopic characterization, quantum chemical, drug likeness parameters and molecular docking studies have been performed for the 2-(5-methyl-1-benzofuran-3-yl) acetic acid (2MBA) molecule. Experimental FT-IR, FT-Raman, NMR ( 1 H, 13 C) and UV–Vis spectral studies have been compared with computationally obtained results. Computational results have been obtained in the framework of density functional theory (DFT). The dimer structure of the 2MBA have also been performed at DFT-B3LYP/6-311++ G (d, p) basis level to inspect the effect of intermolecular interactions on the molecular structure and vibrational frequencies. The geometrical parameters of 2MBA have been observed and compared with the computationally obtained parameters of both monomer and dimer at the DFT level. The harmonic vibrational wavenumbers have been obtained with the help of potential energy distribution and these were compared with the experimental (FT-IR, FT-Raman) data. The experimental NMR ( 1 H, 13 C) chemical shifts have been compared with the chemical shifts obtained by gauge-independent atomic orbital (GIAO) method. The experimental UV–Vis spectrum of 2MBA in ethanol solution compared with theoretically obtained UV–Vis spectra in ethanol and gas phase at TD-B3LYP/6-311++G (d, p) basis level. Natural bond orbital analyses of monomer and dimer have been performed at the DFT-B3LYP/6-311++ G (d, p) basis level. Nonlinear optical properties have also been studied by calculations of the first order hyperpolarizabilities. Frontier molecular orbitals (HOMO-LUMO), important global reactive have also been studied. The local reactivity properties of the 2MBA has been performed by using DFT computations, molecular dynamics (MD) simulations. Pharmaceutical potential of 2MBA molecule has been evaluated by calculations of the most important drug likeness parameters and by molecular docking against the selected protein.

© 2019 Elsevier B.V. In this work the 4,6-dichloro-2-(methylsulfonyl)pyrimidine (DCMSP) has been synthesized from 4,6-dichloro-2-(methylthio)pyrimidine, its molecular and electronic structure was authenticated by detailed spectroscopic signature studies (via SCXRD, FT-Raman, FT-IR and ( 1 H & 13 C) NMR), Hirshfeld surface analysis and DFT calculations. The solid-state crystal structure of DCMSP corroborated by the single crystal X-ray diffraction studies, features C[sbnd]H⋯O and π···π interactions. Quantum chemical calculations of DCMSP have been performed at DFT/B3LYP/6-311++G (d,p) level of theory. The detailed assignment of each the vibrational mode was done on the basis of potential energy distribution (PED) by using the VEDA4 program and these results have been correlated with the experimental data. We calculated the linear and nonlinear optical properties of the title compound to understand the linear and nonlinear optical behavior in both static and dynamic fields using an iterative electrostatic embedding scheme and density functional theory (DFT) methods with standard and long-range corrected functionals. We also performed a study of the linear refractive index and nonlinear optical susceptibility χ (3) of the crystal as a function of frequency. An estimate of linear and nonlinear macroscopic quantities confirms their suitability for nonlinear optical devices such as optical limiting and optical switching. Investigation of local and global reactivity parameters of DCMSP was carried out by the calculation of molecular electrostatic potential (MEP), average local ionization energies (ALIE) surfaces and atomic Fukui indices in the gas phase. Stability in water and sensitivity towards autoxidation process has been investigated by radial distribution function (RDF) and bond dissociation energies (BDE) calculation after molecular dynamic simulations.

© 2019 Elsevier B.V. The synthesis of two pyrazole derivatives, 4-[2-(3-Chloro-2-methylphenyl)hydrazinylidene]-5-methyl-2,4-dihydro-3H-pyrazol-3-one (CPMHP-I)and 4-[2-(3-Chloro-4-fluorophenyl) hydrazinylidene]-5-methyl-2,4-dihydro-3H-pyrazol-3-one (CFHMP-II) and characterization by NMR, FT-Raman, FT-IR and elemental analysis are reported in this work. In this work several computational techniques are used to obtain information about reactive properties of two pyrazole derivatives, CPMHP-I and CFHMP-II. Computational approaches encompassed density functional theory (DFT) calculations, molecular dynamics (MD) simulations and molecular docking. While DFT calculations enabled us to get different reactive properties of title molecules, MD simulations gave us an insight into the stability in water and indicated the possible choices for excipients. The downshift of NH stretching in the IR from the calculated wavenumber is due to hydrogen bonding supported by NBO analysis. The NH stretching modes in the VCD spectra are excellent markers. The docking output propose that CPMHP-I might shows inhibitory activity against human microsomal prostaglandin E synthase 1 and CFHMP-II might exhibit inhibitory activity against mycobacterium tuberculosis type II and can be developed as a new anti-TB drug.

© 2018 Elsevier B.V. A benzoxazole derivative, 2-(p-methylphenyl)-5-(2-(4-ethylpiperazine-1-yl)acetamido) benzoxazole (PMPEPAB) has been synthesized and investigated for its spectroscopic properties within the framework of density functional theory (DFT) calculations and molecular dynamics (MD) simulations. Potential energy distribution analysis was employed in order to assign and compare computationally and experimentally obtained wavenumbers. It was identified that the title compound exhibits antibacterial activity against Gram-positive, Gram-negative bacteria and their drug-resistant isolates and a fungus; Candida albicans. TD-DFT calculations have been used in order to understand charge transfer within PMPEPAB. Natural bond orbital analysis has been carried out to investigate stability of the molecule arising from charge delocalization and hyper-conjugative interactions. Local reactivity properties have been assessed using the MEP and ALIE surfaces and Fukui functions. Stability in water and sensitivity towards hydrolysis has been investigated by MD simulations and calculations of radial distribution functions, while sensitivity towards autoxidation mechanism has been studied by DFT calculations of bond dissociation energies for hydrogen abstraction. Drug likeness parameters are very competitive, while the binding affinity of the title compound with immunoglobulin tandem protein is −6.4 kcal/mol, indicating that title molecule is a candidate to be active component of a new drug for muscular dystrophy.

© 2019 Elsevier B.V. In this study, two novel compounds possessing both acridine and sulfonamide scaffolds were designed by molecular hybridization. These compounds were achieved via condensation of dimedone, 2,3-dichlorobenzaldehyde and sulfadiazine (5SD)/sulfathiazole (5ST) in the presence of a catalytic amount of p-toluenesulfonic acid. The obtained hybrid compounds were characterized by IR, 1 H-NMR, 13 C-NMR and mass spectra. Additionally, the proposed structure of 5SD was proved by single crystal X-ray analysis. Antibacterial activity of the molecules was evaluated against three Gram-positive and two Gram-negative microorganisms using four reference compounds including sulfadiazine and sulfathiazole. Computational analysis on the basis of density functional theory (DFT) calculations, molecular dynamics (MD) simulations and molecular docking have revealed the most important information about the reactive properties of the newly synthesized molecules. DFT calculations have been used in order to identify the molecular sites prone to electrostatic interactions and electrophilic attacks. The same theoretical approach was also used for the identification of the molecular sites possibly sensitive towards the autoxidation mechanism. MD simulations were employed for the determination of the molecular sites prone to interact with water. Finally, molecular docking procedure against dihydropteroate synthase has been used in order to predict the most plausible binding modes and support the experimental data.

© 2018 Elsevier B.V. In the present study, the title compound 1,7-bis(4-bromophenyl)heptane-1,7-dione (BBPHD) was synthesized according to the procedure described in literature, and its solid state crystal structure was characterized by the single crystal x-ray diffraction study. The complete crystallographic information has been reported in the present work. Physicochemical characterization by various spectral tools such as FT-IR, FT-Raman, 1 H NMR, 13 C NMR and UV–visible, have been performed as well and these results have been correlated with the theoretical data. The ground state geometrical optimization of the title compound has been performed using the DFT/B3LYP/6–311++G(d,p) level of theory in gas phase. Extracted molecular structure obtained by x-ray difractometry has been used as the starting molecular structure for geometrical optimizations. Computationally obtained structural and geometric parameters are in good agreement with the experimentally obtained values. The experimental FT-IR and FT-Raman spectral data were compared with the theoretical spectral data and the complete assignment of vibrational wave numbers has been done on the basis of potential energy distribution (PED). In addition, reactive properties have been addressed on the basis of frontier molecular orbital analysis, global chemical reactivity descriptors, natural bond order (NBO) analysis, nonlinear optical (NLO) properties, molecular electrostatic potential (MEP) and average local ionization energy (ALIE) surfaces. Molecular dynamics (MD) simulations have been used in order to study the influence of water to the title compound. The docked ligand forms a stable complex with feruloyl esterase inhibitor and could be considered as a lead compound for the development of new antioxidant drug.

© 2018 Elsevier B.V. Two novel imidazole derivatives, 2-chloro-4,5-dimethyl-1-phenyl-1H-imidazole (C11H11ClN2)(PHENYLI) and 2-chloro-4,5-dimethyl-1-(o-tolyl)-1H-imidazole (C12H13ClN2) (TOLYLI), have been obtained by a procedure based on solvent-free synthesis pathway. Newly synthetized imidazole derivatives have been characterized experimentally by IR, FT-Raman and NMR techniques, while their reactive properties have been predicted on the basis of density functional theory (DFT) calculations and molecular dynamics (MD) simulations. The NLO behavior of the title compounds is greater than that of the standard NLO material urea. MEP analysis gives the most reactive sites in the molecules. TOLYLI compound reveals anti-bacterial activity against all four bacterial strain in both gram positive and gram negative bacteria and PHENYLI compound showed in gram positive and gram negative bacteria both with very good immense and has more sensitive. Interactions of these novel imidazole derivatives with selected protein have been computationally investigated by molecular docking procedure. The docking studies suggest that the compounds might exhibit inhibitory activity against APO-liver alcohol dehydrogenase inhibitor.

© 2018 Elsevier B.V. This paper reports the synthesis of 5-(5-methyl-benzofuran-3-ylmethyl)-3H- [1, 3, 4] oxadiazole-2-thione (5MBOT) and characterization by FT-IR, FT-Raman, 1H NMR, 13C NMR and UV spectral studies. The density functional theory (DFT) calculations have been executed for the 5MBOT using B3LYP/6-31++G (d, p) basis set. The fundamental modes of the vibrations were designated by the potential energy distribution (PED), and the computed and experimental values support each other. The 1H NMR and 13C NMR chemical shifts of 5MBOT were estimated by gauge-including atomic orbitals (GIAO) method and compared with the experimental chemical shifts. The UV–Vis method used to study the visible absorption maxima (λmax) by using Time-Dependent DFT. Further, the Mulliken population analysis (MPA), natural population analysis (NPA) charges, thermodynamic properties at different temperatures were presented. The calculated HOMO and LUMO energies show that charge transfer within the molecule. The natural bonds orbital (NBO) also computed. Optoelectronic properties have been carried out by combination of DFT calculations and molecular dynamics (MD) simulations, in order to assess the potential of this structure for applications in organic electronics. Further, the study encompassed calculations of reorganization energies for holes and electrons and charge transfer rates. DFT calculations have been also used in order to identify locations possibly sensitive towards the autoxidation mechanism, which correlates between bond dissociation energy for hydrogen abstraction and the mechanism. The MD simulations have been used to understand interaction of 5MBOT with water molecules. Molecular docking studies reveals the antifungal activity of 5MBOT may be due to hydrogen bonding and hydrophobic interactions with different antifungal proteins.

The (E)‑1‑(3, 5 dibromo benzylidene) semicarbazide (35DBBS) has been synthesized and characterized using Fourier-transform infrared (FT-IR), Fourier transform Raman (FT-Raman), 1H and 13C Nuclear magnetic resonance (NMR) spectral analyzes. Fukui functions, molecular electrostatic potential (MEP), bond dissociation energies (BDE) and average local ionization energy (ALIE) values have been studied with help of Density Functional Theory (DFT). Further, the stability of 35DBBS in water has been analyzed using molecular dynamics (MD) simulations. The optimized molecular geometrical parameters such as bond length, bond angle and dihedral angle were calculated in different phases viz., gaseous and aqueous and were compared with experimental values. The title compound's binding energy and antifungal ability of the title compound were evaluated using molecular docking studies. Further, Nonlinear Optical Properties (NLO) of 35DBBS have been examined by first order hyperpolarizability studies.

Spectroscopic analysis of 1-(2-fluorophenyl)-3-[3-(trifluoromethyl)phenyl]thiourea (FPTT) is reported. Experimental and theoretical analysis of FPTT, with Molecular Dynamics (MD) simulations, are reported for finding different parameters like: identification of suitable excipients, interactions with water, and sensitivity towards autoxidation. Molecular dynamics and docking show that FPTT can act as a potential inhibitor for new drug. Additionally, local reactivity, interactivity with water, and compatibility of FPTT molecule with frequently used excipients have been studied by combined application of density functional theory (DFT) and MD simulations. Analysis of local reactivity has been performed based on selected fundamental quantum-molecular descriptors, while interactivity with water was studied by calculations of radial distribution functions (RDFs). Compatibility with excipients has been assessed through calculations of solubility parameters, applying MD simulations.

An antiviral azatricyclo derivative is characterized experimentally and analyzed by DFT and MD simulations. Local reactivity properties are provided by ALIE and Fukui function. Oxidation properties and radial distribution functions are calculated by bond dissociation energies of hydrogen abstraction and molecular dynamics simulations. Pronounced interactions with water molecules are determined. Experimental spectra are analyzed theoretically with the help of DFT calculations. Number of intra-molecular H bonds of the halo form was greater than that of the apo form. The binding to estrogen receptor alpha protein further increases its stability. Analysis of the H bond formed by the interaction with the estrogen receptor alpha protein was performed.

Spectroscopic analysis of 1-(2-fluorophenyl)-3-[3-(trifluoromethyl)phenyl]thiourea (FPTT) is reported. Experimental and theoretical analyses of FPTT, with molecular dynamics (MD) simulations, are reported for finding different parameters like identification of suitable excipients, interactions with water, and sensitivity towards autoxidation. Molecular dynamics and docking show that FPTT can act as a potential inhibitor for new drug. Additionally, local reactivity, interactivity with water, and compatibility of FPTT molecule with frequently used excipients have been studied by combined application of density functional theory (DFT) and MD simulations. Analysis of local reactivity has been performed based on selected fundamental quantum-molecular descriptors, while interactivity with water was studied by calculations of radial distribution functions (RDFs). Compatibility with excipients has been assessed through calculations of solubility parameters, applying MD simulations. Graphical abstract Reactive sites identified.

Spectroscopic analysis, DFT studies and surface enhanced Raman scattering of antimicrobial bioactive (Z)-2-[5-(5-bromo-2-hydroxybenzylidene)-4-oxo-2-thioxothiazolidin-3-yl]acetic acid (BPTA) have been studied on different silver sols. Very large changes are observed for Raman and SERS bands. Observed variations in the ring modes may be due to surface π-electron interactions and presence of this indicated that molecule is inclined with respect to the metal surface. Changes in orientation are seen in SERS spectra depending on concentration. The molecular docking results show that binding affinity and interactions with the receptors may be supporting evidence for further studies in design further BPTA pharmaceutical applications. Reactivity properties are obtained from DFT and MD simulations. The quantum-mechanical level of theory has been applied to obtain information about the MEP and ALIE surfaces. These calculations give sensitivity of BPTA towards autoxidation mechanism. An influence of water has been studied computationally, via the MD simulations and RDF analysis. This level of theory was also used to identify possible excipient substance for this molecule.

In this work, density functional theory (DFT) and symmetry-adapted perturbation theory (SAPT) calculations, together with molecular dynamics (MD) simulations, were used to study the interaction between sumanene molecule and 5-fluorouracil (5-FU). 5FU is a known and frequently employed cytostatic drug. To better understand the effects of the curvature of sumanene, we have also considered the interaction between 5-FU and coronene, a sumanene's relative with planar geometry. DFT calculations at B3LYP-D3/6-31G(d,p) level of theory were used to obtain information on binding energies and identify and visualize the noncovalent interactions between the 5-FU and the sumanene/coronene. DFT calculations revealed that 5-FU binds to sumanene's concave side much stronger than to its convex side. The strengths of noncovalent interactions explained the obtained trends in the binding energies. The SAPT0 calculations helped reveal the essential physical contributions to the interaction energies. The importance of the electrostatic component was emphasized in the case of adsorption from sumanene's concave side. Molecular electrostatic potential was compared between the sole molecules and complexes. Simulation of the UV spectra was performed to evaluate whether the binding of 5FU to sumanene could be tracked and monitored by UV spectroscopy. Last but not least, MD simulations were performed to check the influence of temperature on the interaction between sumanene and 5FU. It was established that an increase in temperature significantly decreases the interaction between sumanene and 5FU.

Different types of calcium channels are crucial regulators of many key physiological functions throughout the body. Therefore, calcium channel modulators are accepted as precious molecules for the therapeutic intervention of various pathologies ranging from cardiovascular to neurological diseases. 1,4-dihydropyridines (DHPs) primarily target L-type calcium channel (Cav1.2) for the treatment of hypertension and occupy a central position among all calcium channel blockers. Subsequently, T-type calcium channel Cav3.2 isoform has been established to play a significant role in chronic pain conditions. Despite the growing interest and identification of many compounds with Cav3.2 blocking activities, no molecule has passed the clinical trials and approved for the treatment of pain by now. Our group has recently identified two DHP-based molecules (HM8 and MD20) that selectively blocked T-type over L-type calcium channel. As these compounds hold great therapeutic value as potential drug candidates, we carried out further structural and computational analyses to gain insights into their various properties. Initially, the three-dimensional structure of HM8 was resolved by single-crystal X-ray analysis. The computational analysis encompassed density functional theory (DFT) and molecular dynamics (MD) simulations. DFT calculations were used to identify local reactivity properties and pharmaceutical stability, while time-dependent DFT calculations were used to simulate the UV/Vis spectra and identify the molecular parts principally responsible for the light absorption. MD simulations were used to understand the influence of water on studied molecules, and also to identify the substances that could be potentially used as excipients in pharmaceutical formulations based on HM8 and MD20.

The current emergence of drug-resistant and multidrug-resistant (MDR) Mycobacterium tuberculosis (Mtb) strains has complicated and hampered attempts to eliminate or considerably reduce the global prevalence of the often life-threatening disease tuberculosis (TB). Hence, the development of novel antitubercular agents is crucial to combat this challenge. Here, we applied the molecular hybridization approach to link isoniazid (INH), the frontline antitubercular drug, to various azole rings (pyrazole, imidazole, and triazole) through hydrazone functionality. The designed compounds were synthesized and characterized by using spectral techniques including IR, 1H NMR, 13C NMR and HRMS. Additionally, single crystal X-ray analysis was employed to resolve the proposed chemical structure of INH-T. All compounds were then extensively screened for their antitubercular activities against Mtb H37Rv, drug-resistant and MDR Mtb strains, as well as against a clinical Mtb isolate with no mutation. Notably, INH-azole hybrids presented outstanding antimycobacterial activity with negligible cytotoxicity. Computational methods based on density functional theory calculations and molecular dynamics simulations were applied to identify the characteristic reactive centers of the title compounds, predict stability towards autoxidation, understand their interactions with water molecules and predict the temperature dependence of density. Finally, molecular docking studies revealed that new INH-azole hybrids are likely to exert their antimycobacterial activity via direct inhibition of the Mtb InhA enzyme. © 2022 Elsevier B.V.

© 2019 Elsevier B.V. This article represents the spectroscopic and computational studies of two new pyrazine compounds. In order to establish the structure and functional nature of the compounds, we have employed Fourier transformed infrared (FT-IR) and Raman spectra, nuclear magnetic resonance (NMR) spectra, and ultraviolet (UV) absorptions and have compared them with the simulated computational spectra and found that they are in the agreeable range. Simulated hyperpolarisability values are used to obtain the nonlinear optic (NLO) activity of the compound, to be used in organic electronic materials. The charge transfer and related properties was investigated by the simulation of electronic spectrum with time dependent density functional theory (TD-DFT). Natural transition orbitals (NTO) provides information about which region of the molecules are more involved in the electronic transitions and the charge transfer properties for the lowest energy excitation have been analyzed on the basis of electron density variation. Molecular dynamics simulations provide information about the behavior of the molecule in solutions. Frontier orbital analysis and study of various reactivity descriptors like ALIE and Fukui provided deep knowledge on the reactivity side. Molecular docking has been also performed to investigate the interaction between title molecules and exhibits inhibitory activity against Pseudomonas aeruginosa Enoyl-Acyl carrier protein reductase (Fabl).