Spectral analysis and detailed quantum mechanical investigation of some acetanilide analogues and their self-assemblies with graphene and fullerene

DFT analysis of valproic acid adsorption onto Al12/B12-N12/P12 nanocages with solvent effects

Using density functional theory, the adsorption of valproic acid onto the surface of fullerene-like nanocages was investigated. Valproic acid interacts with the nanocages through the carboxylic group with energies of - 144.14, - 109.71, - 105.22, and - 84.96 kcal/mol. The frontier molecular orbital (FMO) energy levels were considerably altered upon adsorption, resulting in a reduction in energy gap and increase in electrical conductivity. This suggests that nanocages could be used as sensors as well as options for drug administration in biological systems. Solvation effects in water are also reported.

Adsorption properties of dacarbazine with graphene/fullerene/metal nanocages - Reactivity, spectroscopic and SERS analysis

Drug delivery devices are an effective way to minimize anticancer drug toxicity and nanostructures are used in the targeted drug delivery. In the present work, adsorption and interaction behavior of 4-(dimethylaminodiazenyl)-1H-imidazole-5-carboxamide (DAIC) with nano complexes (graphene, fullerene and fullerene like metal cages) are reported theoretically. From the reactivity studies, the electrophilicity index of DAIC-nanoclusters are increasing and this gives the bioactivity of the nanocluster systems. Adsorption energy is highest in the case of AlP and lowest in the case of BP clusters. Mulliken charge distribution of all systems is an evidence for chemical enhancement. DAIC adsorption over nanocages causes changes in electronic properties resulting in chemical enhancement and variation in Raman spectra which suggests that nanocages could be a good candidate for DAIC detection.

Molecular docking, DFT analysis, and dynamics simulation of natural bioactive compounds targeting ACE2 and TMPRSS2 dual binding sites of spike protein of SARS CoV-2

The scientific community is continuously working to discover drug candidates against potential targets of SARS-CoV-2, but effective treatment has not been discovered yet. The virus enters the host cell through molecular interaction with its enzymatic receptors i.e., ACE2 and TMPRSS2, which, if, synergistically blocked can lead to the development of novel drug candidates. In this study, 1503 natural bioactive compounds were screened by HTVS, followed by SP and XP docking using Schrodinger Maestro software. Bio-0357 (protozide) and Bio-597 (chrysin) were selected for dynamics simulation based on synergistic binding affinity on S1 (docking score −9.642 and −8.78 kcal/mol) and S2 domains (-5.83 and −5.3 kcal/mol), and the RMSD, RMSF and Rg analyses showed stable interaction. The DFT analysis showed that the adsorption of protozide/chrysin, the band gap of protozide/chrysin-F/G reduced significantly. From SERS, results, it can be concluded that QDs nanocluster will act as a sensor for the detection of drugs. The docking study showed Bio-0357 and Bio-0597 bind to both S1 and S2 domains through stable molecular interactions, which can lead to the discovery of new drug candidates to prevent the entry of SARS-CoV-2. This in-silico study may be helpful to researchers for further in vitro experimental validation and development of new therapy for COVID-19.

Adsorption of the drug bempedoic acid over different 2D/3D nanosurfaces and enhancement of Raman activity enabling ultrasensitive detection: First principle analysis

The nanocluster-based drug delivery system is of much importance, now days. This manuscript studies the interaction of pristine/substituted/doped GQDs, fullerene, helicene and CNT with bempedoic acid, which is an effective alternative of statins in the treatment of hypercholesteremia. The adsorption energies are calculated at B3LYP-D3/6-311G+(2d,p) level in order to study the adsorption of bempedoic acid over the surfaces of the nanoclusters incorporating Grimme's dispersion correction. Surface enhanced Raman scattering (SERS), which is a sound approach to vibrational spectroscopy, is used in order to detect bempedoic acid. All the studies signify that bempedoic acid can be detected with these nanoclusters and the negative adsorption energies advocate for the possible use of these nanoclusters as effective drug delivery system in case of bempedoic acid. Adsorption energy of bempedoic acid over helicene was found to be the most negative among the mentioned nanocluster systems, while adsorption on the surface of CNT was found to be the least negative.

DFT computational study of trihalogenated aniline derivative's adsorption onto graphene/fullerene/fullerene-like nanocages, X12Y12 (X = Al, B, and Y = N, P)

Adsorption of 2,4,6-tribromoaniline (BA), 2,4,6-trifluoroaniline (FA) and 2,4,6-trichloroaniline (CA) onto the surface of coronene/fullerene/fullerene-like nanocages was investigated by theoretical calculations. Due to the adsorption of BA/FA/CA, there are significant changes in chemical descriptors and nonlinear optical properties. Energy gap values of all nanoclusters are lowered, giving an increase in conductivity of complexes except for fullerene. All complex's ultraviolet visible wavenumber is blue-shifted and especially for fullerene complex, the values are very high. The enhancement of Raman intensities shows that it is possible to design a nanocage sensor for detecting these compounds by surface-enhanced Raman scattering (SERS).Communicated by Ramaswamy H. Sarma.

Spectroscopic investigations, concentration dependent SERS, and molecular docking studies of a benzoic acid derivative

Spectroscopic analysis, density functional theory (DFT) studies and surface enhanced Raman scattering of 4-((3-bromo-5-chloro-2-hydroxybenzylidene)amino)benzoic acid (BCHB) have been studied on different silver colloids concentrations in order to know the particular chemical species responsible for the spectra. For Raman and surface enhanced Raman scattering (SERS) wavenumbers, changes are observed. Observed variations in the modes of ring may be due to interaction of the π-electrons and presence of this indicated that RingII is more inclined than RingI and the BCHB assumes inclined orientation for concentration 10^-3 M. Changes in orientation are seen in SERS spectra depending on concentration. In order to determine the electron-rich and poor sites of BCHB, the molecular electrostatic potential was also constructed. The molecular docking studies show that the bindings and interactions with the receptors may be supporting evidence for further studies in design further BCHB pharmaceutical applications.

DFT computational study towards investigating psychotropic drugs, promazine and trifluoperazine adsorption on graphene, fullerene and carbon cyclic ring nanoclusters

Detection and qualification process related to impurities assume importance in pharmacological drug development programmes and the present article gives the structural and spectral characterisation of phenothiazine derivatives, promazine (PME) and trifluoperazine (TPE) and their self-assembly with graphene/fullerene/carbon ring (CG/CF/CR) systems theoretically. The investigation of adsorption behaviour of these compounds can provide valuable information about its reactivity, electronic and structural properties. Three-dimensional electrostatic potential diagrams were mapped. The frontier orbital energies and energy band gaps of the molecules were computed. Delocalization of charge density between the bonding or lone pair and antibonding orbitals is calculated by NBO analysis. Docking was executed to investigate binding areas of chemical compounds. Bioactivity scores show that the pharmacokinetic and pharmacological properties of the ligands are appropriate leading to be considered potential drug agents. The obtained theoretical wavenumber results of the present study were fully compatible with the experimental results.