Vibrational and electronic absorption spectroscopic profiling, natural hybrid orbital, charge transfer, electron localization function and molecular docking analysis on 3-amino-3-(2-nitrophenyl) propionic acid

8-Aminoquinoline derived two Schiff base platforms: Synthesis, characterization, DFT insights, corrosion inhibitor, molecular docking, and pH-dependent antibacterial study

The current research divulges the synthesis of two new Schiff base (SB) (L NAPH /L O-VAN ) derived from 8-aminoquinoline (8-AMQ) in the presence of 2-hydroxy naphthaldehyde (NAPH) and ortho-vanillin (O-VAN) in CH3OH solvent. They are structurally characterized by spectroscopic methods (IR/Raman/UV-vis/DRS/NMR) and SEM-EDX. SB compounds have a biologically active avenue of azomethine/imine group (H-C=N) that can donate N e's to Mn + ions, showing coordinating flexibility. The -OH and imine (H-C=N) groups are stable in air, light, and alkalis but undergo acidic environments hydrolysis, separating -NH2 and carbonyl compounds. Moreover, buffer solutions with a pH range of 4-6 release aldehyde. Molecular electrostatic potential (MEP), Frontier molecular orbitals (FMO), Fukui function, and Non-linear optical (NLO) were conducted to elucidate SBs chemical potency, optoelectronic significance, and corrosion inhibitor. Accordingly, the calculated ΔE of FMO for L NAPH and L O-VAN is 3.82 and 4.08 eV, ensuring potent biological function. DFT supported the experimental and theoretical IR spectral correlation to enrich better structural insights. NLO-based polarizability (α) and hyperpolarizability (β) factors successfully explore the potential optoelectronic significance. Molecular docking experiments were simulated against DNA, anti-COVID-19, and E. coli. The potential microbiological activity was screened against the bacterial strains E. coli, Klebsiella, Bacillus, and Pseudomonas sp. based on zone of inhibition and MIC values. These experiments also explored the fact that L NAPH and L O-VAN discourage microbial cell biofilms and corrosion. We extensively covered the as-prepared compounds' pH-dependent bacterial effects.

Photophysical, Antioxidant, Antibacterial and NBO, LOL, ELF Analysis of Alkyl Groups Substituted Calix[4]resorcinarenes

In our work to investigate the photophysical, antioxidant, antibacterial, DFT and topological analysis of four C-alkyl calix[4]resorcinarenes (3a-3d - C4RAs). The photophysical properties of C4RAs in selected solvents were recorded using both UV-Visible and fluorescence spectral studies. The absorption and emission maximum of four C4RAs were observed around 280 nm and 318 nm in selected solvents. The solvatochromism with selected solvents were analysed from the plot between Stoke's shift and ETN. The antioxidant activity and antibacterial activity of four C4RAs were evaluated by phosphomolybdate assay and Kirby-Bauer method. The structure of four C4RAs was optimized using DFT B3LYP 6-311G method to calculating the various theoretical parameters in the gas phase. The stability, reactivity, formation of hydrogen bond, donor-acceptor interactions were reported from the interpretation of theoretical values. The non-covalent interactions of four C4RAs were characterized by LOL and ELF topological analysis.

Novel Anthranilic Acid Hybrids-An Alternative Weapon against Inflammatory Diseases

Anti-inflammatory drugs are used to relieve pain, fever, and inflammation while protecting the cardiovascular system. However, the side effects of currently available medications have limited their usage. Due to these adverse effects, there is a significant need for new drugs. The current trend of research has shifted towards the synthesis of novel anthranilic acid hybrids as anti-inflammatory agents. Phenyl- or benzyl-substituted hybrids exerted very good anti-inflammatory effects in preventing albumin denaturation. To confirm their anti-inflammatory effects, additional ex vivo tests were conducted. These immunohistochemical studies explicated the same compounds with better anti-inflammatory potential. To determine the binding affinity and interaction mode, as well as to explain the anti-inflammatory activities, the molecular docking simulation of the compounds was investigated against human serum albumin. The biological evaluation of the compounds was completed, assessing their antimicrobial activity and spasmolytic effect. Based on the experimental data, we can conclude that a collection of novel hybrids was successfully synthesized, and they can be considered anti-inflammatory drug candidates-alternatives to current therapeutics.

Structural, electronic, intermolecular interaction, reactivity, vibrational spectroscopy, charge transfer, Hirshfeld surface analysis, pharmacological and hydropathy plot on 5-Bromo nicotinic acid - Antiviral study (Hepatitis A, B, and C)

The therapeutic properties of 5-Bromonicotinatic acid (5BNA) were studied for antiviral illnesses like Hepatitis A, Hepatitis B and Hepatitis C and the influence of electron-donating and electron-withdrawing properties of functional groups on the nicotinic acid was evaluated and represented in this study using the DFT approach. The molecular parameters were determined for both gases as well as for various solvent phases. The reactive areas in the compound are examined utilising Fukui analysis. The molecular interactions are accomplished by recognising the different types of bonding found in the compound using the AIM, ELF, LOL, RDG and IRI. Solvation investigations were demonstrated to have an influence on molecular orbital energy, ESP, UV-Vis and NLO analyses. Electron-hole, NBO and Hirshfeld investigations are used to investigate the transfer of charges and interactions inside the molecule. The method of vibrational spectroscopy (IR and Raman) is used to differentiate and identify the various types of vibrations displayed by the compound. The hydropathy plots for the proteins 2A4O, 6CWD and 2OC8 associated with Hepatitis A, Hepatitis B and Hepatitis C illustrate the disquiet and attraction of the amino acids towards the water.

Photophysical, antioxidant, antibacterial and NBO, LOL, ELF analysis of alkyl groups substituted calix[4]resorcinarenes.. [DOI: 10.21203/rs.3.rs-2707368/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

In our work to investigate the photophysical, antibacterial, theoretical and topological analysis of four C-alkyl calix[4]resorcinarenes (C4RAs). The solvatochromism and photophysical properties of C4RAs in different solvents were recorded in both UV-Visible and fluorescence spectral studies. The total antioxidant capacity and antibacterial activity of four C4RAs were evaluated by phosphomolybdate assay and kirby-bauer method. Theoretical parameters such as HOMO, LUMO, energy gap and Mulliken atomic charges and NBO were optimized by DFT B3LYP 6-311G method. From the results of HOMO and LUMO energies were used to determine the theoretical parameters of four C4RAs. The nucleophilic and electrophilic substitution reactivity of four C4RAs were analyzed by molecular electrostatic potential map analysis. Natural bonding orbital analysis was used to determine the intramolecular charge transfer within the energy difference between acceptor and donor orbitals. The non-covalent interactions of four C4RAs were characterized by LOL and ELF topological analysis.

The Influence of Syringic Acid and Erucic Acid on the Antioxidant Properties of Natural Rubber: Experimental and Molecular Simulation Investigations

In this work, the influence of syringic acid (SA) and erucic acid (EA) on the oxidation resistance of natural rubber (NR) was investigated by combining experimental and computational methods. The antioxidant activities of SA and EA were predicted by calculating the enthalpy of bond dissociation (BDE), the anti-migration ability of antioxidants (AOs) in the rubber matrix by calculating the mean square displacement (MSD), and the effect of antioxidants on oxygen barrier properties of rubber materials by calculating the permeability coefficient (P). The predicted result is that EA has a better comprehensive performance than SA. The DPPH (2,2-diphenyl-1-picrylhydrazyl) test and mechanical properties test demonstrated the results predicted by the simulations. Both SA and EA can protect natural rubber, while EA has a better comprehensive effect.

Interaction of 5-fluorouracil anticancer drug with nucleobases: insight from DFT, TD-DFT, and AIM calculations

In this study, the interaction of 5-fluorouracil (5FU) drug with adenine (A), guanine(G), cytosine(C), uracil (U), and thymine (T) nucleobases of DNA and RNA are surveyed at the ωB97XD/LANL2DZ, M06-2X/6-31G (d, p), MPW1PWQ1/6-31G(d, p), PBEPBE/6-31(d, p) and ωB97XD/6-31G(d, p) levels of density functional theory (DFT). The considered complexes of 5FU drug with nucleobases are optimized at the above level of theories. Max Force and RMS of optimization criteria are 0.00035 (Ha), and 0.0003 respectively. From optimized structures, the adsorption energy, thermodynamic parameters in gas and solvent media, quantum theory atom in molecule (QTAIM), electron localized function (ELF), and reduced density gradient (RDG) are calculated at ωB97XD/LANL2DZ and M06-2X/6-31G (d, p) level of DFT theory. The QTAIM, ELF, and RDG results confirm that the nature of bonding between 5FU drug with A, C, G, U, and T nucleobases is electrostatic or hydrogen bond type. The adsorption and thermodynamic energy results demonstrate that the interaction of the 5FU drug with C and G nucleobases is stronger than other nucleobases. The results of this study can be suggested the mechanism of interaction of the 5FU drug with nucleobases of DNA and RNA.Communicated by Ramaswamy H. Sarma.

Photocatalytic decontamination of tetracycline and Cr(VI) by a novel α-FeOOH/FeS2 photocatalyst: One-pot hydrothermal synthesis and Z-scheme reaction mechanism insight

Tetracycline and Cr(VI) as non-biodegradable environmental contaminants have attracted increasing attention because of their chronic toxicity. In this regard, the environmentally friendly Z-scheme photocatalytic decontamination system has been widely used for contaminant treatment. Herein, a novel 3D Z-scheme α-FeOOH/FeS₂ composite photocatalyst was successfully synthesized for the first time via a simple one-pot hydrothermal method. X-ray diffraction (XRD) and Fourier-transform infrared (FT-IR) analyses and high-resolution transmission electron microscopy (HRTEM) and X-ray photoelectron spectroscopy (XPS) demonstrated that the O component of the heterogeneous nanostructures formed by the FeOFe linkages in α-FeOOH was replaced by S to generate FeSFe linkages in the resulting FeS₂. As expected, the novel 3D Z-scheme α-FeOOH/FeS₂ composites exhibited remarkable photocatalytic activity for Cr(VI) reduction and tetracycline degradation compared to pure α-FeOOH. Photoluminesence (PL) measurement and electrochemical impedance spectroscopy (EIS), as well as density functional theory (DFT) calculations, suggested that the enhanced photocatalytic activity of the Z-scheme α-FeOOH/FeS₂ composite can be attributed to the improved photo-absorption properties and the effective separation of photo-induced charge carriers caused by the Z-scheme system of the as-prepared 3D α-FeOOH/FeS₂ composites. Thus, this work may facilitate the effective design of α-FeOOH-based photocatalysts.

Vibrational spectra, Hirshfeld surface analysis, molecular docking studies of (RS)-N,N-bis(2-chloroethyl)-1,3,2-oxazaphosphinan-2-amine 2-oxide by DFT approach

The Cyclophosphamide (CYC) is used as an anti cancer agent. It is chemically known as (RS)-N,N-bis(2-chloroethyl)-1,3,2-oxazaphosphinan-2-amine 2-oxide. The vibrational assignments survey of the CYC was implemented by employing FT-IR and FT-Raman spectroscopic investigation and the results are compared with theoretical features. The optimized geometrical parameters, IR intensity and Raman Activity of the vibrational bands of CYC were determined from the B3LYP functional with 6-311++G (d, p) level of theory. In the current work, quantum chemical calculations were adopted to contemplate the vibrational assignments of CYC and the outcomes are compared with experimental findings. Molecular Electrostatic Potential (MEP) and HOMO-LUMO energies are very effective in the examination of charge transfer and distribution of the molecular structure. The molecular orbital contributions were evaluated by using the Total Density of States (TDOS). The analysis of Natural Bond Orbital (NBO), Mulliken population and Fukui function studies were done. Intermolecular interaction of the title compound was examined through Hirshfeld surface analysis. The evaluation of drug-likeness was accomplished in accordance with Lipinski's Rule of Five and molecular descriptors were utilized to predict the ADMET profiles of the CYC molecule. The recent research studies reports that the structural and bio-activity of the CYC was affirmed by the docking analysis of CYC with protein PI3K/AKT inhibitor, it acts as anti-lung cancer agent.

A detailed computational investigation on the structural and spectroscopic properties of propolisbenzofuran B

This investigation deals with some structural and spectroscopic aspects of propolisbenzofuran B molecule as one of the most important bioactive molecules which exists in the bee propolis composition. FT-IR vibrational analysis carried-out at B3LYP/6-311++G(d,p) level of the theory. ¹H and ¹³C NMR chemical shift have been predicted with GIAO method. TD- DFT calculations have been established to predict the UV- Vis spectral analysis for propolisbenzofuran B molecule. The detailed structural analysis such as electronic characterization, HOMO and LUMO, DOS plot, Molecular Electronic Potential (MEP), Natural Bond Orbital (NBO) are performed and discussed for studied molecule.