Spectroscopic analysis of 8-hydroxyquinoline derivatives and investigation of its reactive properties by DFT and molecular dynamics simulations

SERS analysis, DFT, and solution effects regarding the structural and optical characteristics of folic acid biomolecule adsorbed on a Cu3 metal cluster

The optical characteristics of folic acid (ABP) and metal clusters of copper (Cu3) at various locations were investigated by means of density functional theory (DFT) computations. Mulliken charge analysis and molecular electrostatic potential (MEP) surface show how charge moves from Cu3 to ABP through the various groups. The peak in the UV-Vis spectra of ABP-Cu3 is caused by bonding and anti-bonding orbitals. In both vacuum and aqueous conditions, the polarizability values of ABP-Cu3 cluster are significantly higher than those of pure ABP, indicating a possible enhancement of the nonlinear optical (NLO) effect. Our research investigates the possibility of using ABP adsorbed metal clusters for NLO materials. Surface enhanced Raman scattering (SERS) in the ABP adsorbed metal clusters enhances the vibrational modes of ABP. Adsorption energies are found to be in the range -17.08 to -58.52 kcal/mol in vacuum and -53.34 to -93.44 kcal/mol in aqueous medium for the different configurations for ABP-Cu3. It indicates that metal clusters adsorbed by ABP are stable in the aqueous media. Experimental IR and UV-Vis of ABP is in agreement with theoretically predicted ones.

Development of a Clioquinol Nanocarrier as a New, Promising Option for the Treatment of Dermatomycosis

Dermatomycosis is a common fungal infection, and its treatment is limited by few antifungal agents. Clioquinol (CQ) is an antiparasitic agent that has been studied for new uses, such as antifungal and antiviral applications. CQ was incorporated into a lipid-based nanocarrier as a new, promising option for dermatomycosis. This study aimed to develop a CQ-loaded lipid-based nanocarrier for cutaneous application and to evaluate its antifungal activity. CQ-loaded nanoformulation (LBN-CQ) was developed using the ultrasonication method, and the particle size, polydispersity index (PDI), pH, zeta potential, and drug content were monitored for 45 days. To evaluate antifungal activity, broth microdilution and a time-kill assay were performed. LBN-CQ presented a particle size of 91 ± 3 nm and PDI of 0.102 ± 0.009. The zeta potential and pH values were -9.7 ± 2.0 mV and 6.0 ± 0.1, respectively. The drug content was 96.4 ± 2.3%, and the encapsulation efficiency was 98.4%. LBN-CQ was able to reduce the minimum inhibitory concentration (MIC) in a 2-fold or 4-fold manner in most of the tested strains. Additionally, LBN-CQ presented stable fungistatic action that was not concentration- or time-dependent. In conclusion, the developed CQ-loaded nanocarrier is a promising treatment for skin fungal infections and a promising candidate for future randomized clinical trials.

Experimental spectra, electronic properties (liquid and gaseous phases) and activity against SARS-CoV-2 main protease of Fluphenazine dihydrochloride: DFT and MD simulations

The Gaussian 09 DFT tool is used to investigate the formational electronic behaviour, reactivity analysis and biological properties of fluphenazine dihydrochloride (FDD). The quantum computation is used to determine the spectroscopic and vibrational assignments of FDD. The NBO method explains charge transfer and molecular interactions. Energy gap values are determined using FMO analysis in different solvents and toluene is a better solvent due to higher value of solvation energy. The UV-visible spectra are investigated in various solvents using the TD-DFT method. Electrostatic potential, the wave function related properties such as LOL, NCI and RDG are determined in gaseous phase. Furthermore, the drug likeness is analyzed. At last, a docking study with MD simulation is used to investigate FDD's antiviral activity against SARS-CoV-2 main protease.

Computational investigation, comparative approaches, molecular structural, vibrational spectral, non-covalent interaction (NCI), and electron excitations analysis of benzodiazepine derivatives

The present work explores the structural parameters and vibrational frequencies as well as molecular interactions of benzodiazepine derivatives, such as clothiapine (CT), clozapine (CZ), and loxapine (LX). Employing fitting experimental data to theoretical results is used to assess the structural parameters of heading composites. The main assignment is passed out according to the overall distribution of energy of the vibrational modes. From the hyper-conjugative interaction, the permanency of the structure had been predicted through natural bond orbital analysis; it is also used to identify the bonding and antibonding regions of the molecules. Moreover, electrostatic potential (ESP), density of states (DOS), and charge transfer occurring of the molecule among HOMO as well as LUMO energy were calculated and presented; utilizing electron localized field (ELF), localized orbital locator (LOL), and reduced density gradient (RDG), the chemical interactive regions are found. Additionally, mean polarizability (α_tot), the first-order hyperpolarizability (β_tot), and softness and hardness of the entitled compounds were also performed. The interaction between protein-ligand was also predicted by docking studies.

Vibrational spectroscopy, quantum computational and molecular docking studies on 2-chloroquinoline-3-carboxaldehyde

The quantum mechanical density functional theory (DFT) approach was used to analyze vibrational spectroscopy for the title compound 2-chloroquinoline-3-carboxaldehyde, and the observations were compared to experimental results. B3LYP with the 6-311++ G (d, p) basis set produces the optimized molecular structure and vibrational assignments. The charge delocalization and hyper conjugative interactions were studied using NBO analysis. Fukui functions were used to determine the chemical reactivity of the examined molecule. The linear polarizability, first order polarizability, NLO and Thermodynamic properties are calculated. Additionally, Molecular electrostatic potential (MEP) and HOMO-LUMO are reported. Multi wavefunction analysis like ELF (Electron Localization Function) and LOL (Localized Orbital Locator) are analyzed. For the headline compound, drug-likeness properties were examined. Molecular docking analysis on the examined molecule are done to understand the biological functions of the headline molecule and the minimum binding energy, hydrogen bond interactions, are analyzed.

Improved pharmacological properties of nitrotyrosine drug via fluorination: A theoretical study

It has become obvious that fluorinated drugs have a significant role in medicinal applications. In this study, the fluorination of 3-nitrotyrosine as an anti-Parkinson and anti-Alzheimer drug was explored using density functional theory calculations. We have investigated the most important chemical properties of 3-nitrotyrosine that affect the pharmacological activity of the drug. We found that the intramolecular hydrogen bonding and intramolecular charge of the drug were influenced by fluorine substitution. Our results also reveal that the fluorination altered the stability, solubility, and molecular polarity of the 3-nitrotyrosine drug. The density of state analysis also determines sharp resonance states of fluorine atoms with the 3-nitrotyrosine drug states particularly in the highest molecular orbital reigns, suggesting hybridization of the fluorine states with the state of the drug. Moreover, our results show that the electronic spectra of fluorinated derivatives of 3-nitrotyrosine drug exhibit a red shift toward higher wavelengths (lower energies). Our calculations show that the free energy transfers of fluorinated derivatives of the 3-nitrotyrosine drug in water were negative that it meant that the designed molecules dissolving in aqueous phase occurred simultaneously. Consequently, the results of the present study show that the fluorination of 3-nitrotyrosine drug could be considered as a promising strategy to design useful drugs with better pharmacological properties.

Cocrystals of hydrochlorothiazide with picolinamide, tetramethylpyrazine and piperazine: quantum mechanical studies, docking and modelling of the photovoltaic efficiency for DSSC

Cocrystals are of immense applications in crystal engineering and pharmaceutical chemistry. Hydrochlorothiazide is found to form cocrystals with picolinamide (H1), tetramethylpyrazine (H2) and piperazine (H3). It was characterized using IR spectra, and quantum mechanical calculations for geometry and other properties. Frontier orbital energies are used to predict the energy properties and model the possible charge transfer between the constituents of the cocrystal. The frontier molecular orbital analysis indicates chemical reactivity and bioactivity of the cocrystals. The MEP surface reveals the various reactive surfaces in the cocrystal system, which is very important in deciding various biological activities. The UV-Vis spectra show the possible electronic transitions of the molecules. Simulated electronic spectra using TDDFT method with CAM-B3LYP functional were used to investigate the suitability of the cocrystals to be used in DSSC. Moreover, the molecular docking analysis proves that the cocrystals can act as potential inhibitors and paves the way for developing effective drugs.

An integrated exploration of pharmacological potencies of Bischofia javanica (Blume) leaves through experimental and computational modeling

Bischofia javanica (Blume), an edible wild plant, has both prospective nutraceutical and therapeutic properties. Here, we intended to explore the pharmacological potentials of the methanol extract of B. javanica (MEBJ) through integrated approaches. Phytochemical screening revealed the presence of important phytoconstituents which were found to be safe during cytotoxicity analysis. The sedative potential of MEBJ (200 and 400 mg/kg) was determined by employing open field, hole cross, and thiopental sodium-induced sleeping time tests, where a significant reduction of the locomotor performance and an enhancement in the duration of sleeping have been observed, respectively. In addition, mice treated with MEBJ exhibited superior exploration during both elevated plus maze and hole board tests. In parallel, anti-diabetic potency was investigated via alpha-amylase inhibitory assay, where a dose-response increase in the percentage of inhibition has been marked. A similar response, such as an increased percentage of clot lysis, was observed during the thrombolytic test. Furthermore, molecular docking was performed with the identified compounds, demonstrated strong binding affinities to the target receptors of the experiments as mentioned above. Also, ADME/T and toxicological parameters verified the drug-like properties of the identified compounds. Collectively, these results indicate bioactivity of Bischofia javanica, which can be a potential candidate in the food and pharmaceutical industries.

Detailed quantum mechanical studies on bioactive benzodiazepine derivatives and their adsorption over graphene sheets

Estazolam (Z1) and related derivatives, adinazolam (Z2), alprazolam (Z3), 4-hydroxyalprazolam (Z4) and triazolam (Z5) have been studied by using various computational tools to analyze their geometry and spectral characteristics. The compounds were found to interact with graphene monolayer results shows that there is enhancement in various physico-chemical descriptors and surface enhanced Raman spectra (SERS). The various reactive descriptors obtained from the FMO analysis predict the reactive nature of the compound. The various lone pair/sigma to pi conjugation was analyzed using NBO formalism, which provides valuable information about intra molecular electron transfer which is vital in predicting the inherent stability of the molecule. Simulated electronic spectra using TD-DFT and CAM-B3LYP functional are discussed in detail with respect to electronic transitions and light harvesting efficiency. Suitability of candidates as a photo sensitizer in dye sensitized solar cells was studied and 4-Hydroxyalprazolam is identified as a suitable candidate. Nucleophilic and electrophilic regions of the molecules are identified using MESP, which adds to the reactivity information. It can be seen that the highest interaction energy has been obtained in the case of the Z5-graphene system, while the lowest interaction energy has been obtained in the case of the Z1-graphene system. Docking indicates that the ligands adsorbed over graphene also form stable complexes with the receptors as indicated by the high binding affinity energy values.

Detailed molecular structure (XRD), conformational search, spectroscopic characterization (IR, Raman, UV, fluorescence), quantum mechanical properties and bioactivity prediction of a pyrrole analogue

Pyrroles are an exciting class of organic compounds with immense medicinal activities. This manuscript presents the structural and quantum mechanical studies of 1-(2-aminophenyl) pyrrole using X-Ray diffraction and various spectroscopic methods like Infra-Red, Raman, Ultra-violet and Fluorescence spectroscopy and its comparison with theoretical simulations. The single-crystal X-ray diffraction values and optimized geometry parameters also were within the agreeable range. A fully relaxed potential energy scan revealed the stability of the possible conformers of this molecule. We present the density functional theory results and assignment of the vibrational modes in the infrared spectrum. The experimental and scaled simulated vibrations matched when density functional theory simulations (B3LYP functional with 6–311++G∗∗). The electronic spectrum was simulated using time-dependent density functional theory with CAM-B3LYP functional in dimethylsulphoxide solvent. The fluorescence spectrum of the compound was studied at different excitation wavelengths in the dimethylsulphoxide solvent. The stability of the molecule by intramolecular electron transfer by hyperconjugation was studied with the natural bond orbital analysis. Frontier molecular orbitals and molecular electrostatic potentials of the compound gave an idea about the reactive behaviour of the compounds. Prediction of activity spectral studies followed by docking analysis indicated that the molecule is active against arylacetonitrilase inhibitor.

DFT and molecular docking investigations of oxicam derivatives

The organic molecule tenoxicam and similar derivatives, piroxicam and isoxicam have been studied by quantum chemical theory (DFT), FT-Raman and FT-IR. By FMOs energies the charge transfer inside the molecules are obtained. The UV-Vis spectra of the compounds are simulated to study the electronic transition in the target molecules. By using natural bond orbital (NBO), charge delocalization analyzes arising from hyper conjugative interactions and the stability of the molecules are obtained. First order hyperpolarizability of piroxicam is higher than that of isoxicam and tenoxicam. The reactive areas are thoroughly studied by MEP. Prediction of Activity Spectra gives activities, anti-inflammatory, CYP2C9 substrate and gout treatment. Docked ligands form a stable complex with the receptors.

Spectroscopic, quantum computational and molecular docking studies on 1-phenylcyclopentane carboxylic acid

The vibrational wavenumbers of optimized molecular structure of 1-phenylcyclopentane carboxylic acid (1PCPCA) molecule have been calculated by quantum chemical theory and compared with experimental results. The density functional theory (DFT) approach is followed using the method B3LYP and 6-311++G(d,p) basis set. Using potential energy distribution, all the assignments of the basic vibrational modes were calculated. Natural bond orbital (NBO) and atoms in molecules (AIM) topological studies applied to get the intermolecular interactions of the compound. ¹H and ¹³C chemical shift of NMR was estimated on the molecule and also compared with the experimental spectra. In order to find the band gap, the time-dependent (TD-DFT) method is used to get the higher order energy levels properties and also compared with experimental data of UV-vis spectrum. From the analysis of various spectroscopic studies, there is a good relationship between the experimental and theoretical values obtained. Quantum characters, bio-active nature and reactive areas of the molecule are revealed by Fukui function, molecular electrostatic potential (MEP) and Hirshfeld surface studies. The human enzyme steroidogenic types and their protein targets were tested with this molecule by molecular docking.

Conformational profile, vibrational assignments, NLO properties and molecular docking of biologically active herbicide1,1-dimethyl-3-phenylurea

1,1-Dimethyl-3-phenylurea (known as fenuron) which is a phenyl urea-based widely used herbicide exhibits interesting structural and conformational properties and a notable biological activity. A detailed analysis on the vibrational, molecular and electronic characteristics of fenuron has been carried out. Potential energy scans (PESs) performed at the B3LYP/6-311++G(d,p) level of theory predicted two possible minima corresponding to the optimized anti and synforms resulting from the internal rotation about the N-C bond. The presence of an auxochrome together with the interaction with DMSO solvent exhibited a blue shift corresponding to the C=O orbitals. Delocalization of HOMO and LUMO orbital facilitated the charge transfer effect in the molecule. The calculated HOMO-LUMO energies, chemical potential, energy gap and global hardness suggested a low softness value for the compound while its biological activity was described by the value of electrophilicity. Chlorine substitution in the phenyl ring influenced the orbital delocalization for ortho and para substitutions but that of meta remained unaffected. NLO properties were noticed to increase due to chlorine substitution in the parent molecule. The docking results suggested that the compound exhibits an inhibitory activity against mitochondrial ubiquinol-cytochrome-c reductase and can be developed as a potential anticancer agent.