Synthesis, spectroscopic (FT-IR, FT-Raman, NMR, UV–Visible), Fukui function, antimicrobial and molecular docking study of (E)-1-(3-bromobenzylidene)semicarbazide by DFT method

Comprehensive Study of the Ammonium Sulfamate-Urea Binary System

The physicochemical properties of binary systems are of great importance for the application of the latter. We report on the investigation of an ammonium sulfamate-urea binary system with different component ratios using a combination of experimental (FTIR, XRD, TGA/DSC, and melting point) and theoretical (DFT, QTAIM, ELF, RDG, ADMP, etc.) techniques. It is shown that, at a temperature of 100 °C, the system under study remains thermally and chemically stable for up to 30 min. It was established using X-ray diffraction analysis that the heating time barely affects the X-ray characteristics of the system. Data on the aggregate states in specified temperature ranges were obtained with thermal analysis and determination of the melting point. The structures of the ammonium sulfamate-urea system with different component ratios were optimized within the density functional theory. The atom-centered density matrix propagation calculation of the ammonium sulfamate-urea system with different component ratios was performed at temperatures of 100, 300, and 500 K. Regardless of the component ratio, a regular increase in the potential energy variation (curve amplitude) with an increase in temperature from 100 to 500 K was found.

A Comprehensive Study of N-Butyl-1H-Benzimidazole

Imidazole derivatives have found wide application in organic and medicinal chemistry. In particular, benzimidazoles have proven biological activity as antiviral, antimicrobial, and antitumor agents. In this work, we experimentally and theoretically investigated N-Butyl-1H-benzimidazole. It has been shown that the presence of a butyl substituent in the N position does not significantly affect the conjugation and structural organization of benzimidazole. The optimized molecular parameters were performed by the DFT/B3LYP method with 6-311++G(d,p) basis set. This level of theory shows excellent concurrence with the experimental data. The non-covalent interactions that existed within our compound N-Butyl-1H-benzimidazole were also analyzed by the AIM, RDG, ELF, and LOL topological methods. The color shades of the ELF and LOL maps confirm the presence of bonding and non-bonding electrons in N-Butyl-1H-benzimidazole. From DFT calculations, various methods such as molecular electrostatic potential (MEP), Fukui functions, Mulliken atomic charges, and frontier molecular orbital (HOMO-LUMO) were characterized. Furthermore, UV-Vis absorption and natural bond orbital (NBO) analysis were calculated. It is shown that the experimental and theoretical spectra of N-Butyl-1H-benzimidazole have a peak at 248 nm; in addition, the experimental spectrum has a peak near 295 nm. The NBO method shows that the delocalization of the aσ-electron from σ (C1-C2) is distributed into antibonding σ* (C1-C6), σ* (C1-N26), and σ* (C6-H11), which leads to stabilization energies of 4.63, 0.86, and 2.42 KJ/mol, respectively. Spectroscopic investigations of N-Butyl-1H-benzimidazole were carried out experimentally and theoretically to find FTIR vibrational spectra.

Catalytic ozonation of aqueous 4-methylquinoline by fluorinated ceramic honeycomb

Metal-free catalysts for catalytic ozonation have attracted more and more attentions to eliminate the risk of secondary pollution of heavy metals in water or wastewater treatment. Herein we prepared fluorinated ceramic honeycomb (FCH) with the dip-calcination method using NH₄F as the modifier over ceramic honeycomb (CH) to catalyze the ozonation of 4-methylquinoline (4-Meq), a typical harmful quinoline derivate discharged from coal or petroleum industries. The ozonation degraded 54.9% of 4-Meq and removed 14.4% of chemical oxygen demand (COD) in 30 min, while the FCH catalytic ozonation degraded 77.8% of 4-Meq and removed 29.2% of COD. In addition, FCH has a stable catalytic performance and can effectively remove 4-Meq as well as COD in real coal gasification wastewater. The fluorination endows the surface of the FCH with abundant Si-F groups as active acid sites and aluminum-attached hydroxyl groups, and then enhance the ozone decomposition to generate free reactive oxygen species (ROS). Those ROS includes free hydroxyl radicals, free superoxide radicals as well as singlet oxygen, and the free hydroxyl radical plays a major role in the degradation and COD removal of 4-Meq. The degradation of 4-Meq follows two pathways of the demethylation, benzene ring opening and the pyridine ring-opening. This work demonstrates an efficient catalyst for ozonation to root out the risk of the heavy metals pollution from catalysts, and provides an insightful understanding of the FCH catalytic ozonation.

Vibrational Spectroscopy, Quantum Computational and Molecular Docking Studies on 2-[(1H-Benzimidazol-1-yl)-methyl]benzoic Acid

Experimental and theoretical investigations on the optimized geometrical structure, electronic and vibrational features of 2-[(1H-benzimidazol-1-yl)-methyl]benzoic acid are provided using the B3LYP/6-311++G(d,p) basis set. The Vibrational Energy Distribution Analysis (VEDA) program was used to perform the vibrational assignments and calculate the Potential Energy Distribution (PED). The acquired FT-IR and FT Raman data were used to complete the vibrational assignment and characterization of the compound fundamental modes. Theoretical and actual NMR chemical shifts were found to be quite similar. The UV-vis spectrum of 21HBMBA, as well as effects of solvents, have been investigated. The calculated HOMO and LUMO energies reveal that charge transfer happens within the molecule and MEP surface to be a chemically reactive area appropriate for drug action. Furthermore, a thorough examination of Non-Bonding Orbitals, excitation energies, AIM charges, Fukui functions and the Electron Localization Function (ELF) is carried out. The research is also expanded to compute first-order hyperpolarizability and forecast NLO characteristics. The details of the docking studies aided in the prediction of protein binding.

A Novel Insight into Screening for Antioxidant Peptides from Hazelnut Protein: Based on the Properties of Amino Acid Residues

This study used the properties of amino acid residues to screen antioxidant peptides from hazelnut protein. It was confirmed that the type and position of amino acid residues, grand average of hydropathy, and molecular weight of a peptide could be comprehensively applied to obtain desirable antioxidants after analyzing the information of synthesized dipeptides and BIOPEP database. As a result, six peptides, FSEY, QIESW, SEGFEW, IDLGTTY, GEGFFEM, and NLNQCQRYM were identified from hazelnut protein hydrolysates with higher antioxidant capacity than reduced Glutathione (GSH) against linoleic acid oxidation. The peptides having Tyr residue at C-terminal were found to prohibit the oxidation of linoleic acid better than others. Among them, peptide FSEY inhibited the rancidity of hazelnut oil very well in an oil-in-water emulsion. Additionally, quantum chemical parameters proved Tyr-residue to act as the active site of FSEY are responsible for its antioxidation. This is the first presentation of a novel approach to excavating desired antioxidant peptides against lipid oxidation from hazelnut protein via the properties of amino acid residues.

Growth, spectral, optical, electrical and computational analysis of sodium oxalate single crystals

Single crystals of Sodium Oxalate (SO) were grown by adopting the slow evaporation solution growth approach from aqueous solution. The prominent functional groups seen in the SO crystal were distinctly detected with Fourier transform infrared and FT-Raman spectral analysis. The cut-off wavelength of 230 nm was measured using Ultraviolet -visible spectral analysis. Theoretical quantum chemical computations were done by DFT using Gaussian software package. The different properties such as structural, vibrational and electronic properties of SO was studied at the B3LYP/LanL2DZ level. The chemical activity of SO molecule was revealed by HOMO-LUMO energies. From Topology analysis the chemical significance of the molecules has been enunciated. The electron density centered on local reactivity descriptors like Mulliken atomic charges and Fukui function were calculated to describe the chemical reactivity of the SO compound. The mechanical property of the grown crystal was disclosed from Vicker's micro hardness test carried out on the grown SO crystals and the test confirms the soft nature of the crystal. The dielectric behavior of SO crystal was completely investigated for different temperatures and the activation energies were calculated for different frequencies.

Spectroscopic elucidation (FT-IR, FT-Raman and UV-visible) with NBO, NLO, ELF, LOL, drug likeness and molecular docking analysis on 1-(2-ethylsulfonylethyl)-2-methyl-5-nitro-imidazole: An antiprotozoal agent

1-(2-ethylsulfonylethyl)-2-methyl-5-nitro-imidazole (1EMI) C₈H₁₃N₃O₄S also known as Tinidazole, selected for its antiprotozoal property is extensively used for spectroscopic elucidations and computational aspects using density functional methods. Along with spectral conclusions, further investigations on fundamental reactive properties such as electrical, optical, nonlinear combined with DFT simulations were performed. Molecular docking procedure supports the results of chosen appropriate antiprotozoal agent based on ligand-protein interactions. Experimental and simulated (B3LYP/6-311++G (d,p)) IR and Raman spectra showed concurrence. NLO analysis through first order hyperpolarizability parameter helps in finding the potential of 1EMI as a good NLO candidate. Charge delocalization and the stability of the compound were discussed using natural bond orbital (NBO) analysis. Furthermore, Electron localization function (ELF), local orbital locator (LOL), and Frontier molecular orbitals (FMO) were studied. Besides, Mulliken population analysis on atomic charges, Energy gap, chemical potential, global hardness, softness, ionization potential, electronegativity, electrophilicity index along thermodynamic parameters (enthalpy, entropy and heat capacity) have been calculated. Drug likeness parameters and molecular docking approach enabled to check pharmaceutical potential and biological activity of 1EMI. The biological activity of 1EMI through ligand and protein interactions have been confirmed theoretically for the treatment of Malaria, Invasive aspergillosis and Mycobacterium tuberculosis with respect to chosen proteins. Three different activity targets and protein interactions are quite successful revealing the bond distances, intermolecular energy, binding energy and inhibition constant. 2D interaction profile image of the two maximum interacted proteins and also Ramachandran plot used to show stereochemistry of selected protein. The activities of 1EMI were studied in accordance with literature survey and the results were presented.

Molecular conformation, vibrational spectroscopic and NBO analysis of atenolol and atenolol-hydrochlorothiazide cocrystals

Geometry optimization of atenolol (ATN) in the gas phase was carried out using B3LYP-D3BJ/6-31++G(d,p), CAM-B3LYP/6-31++G(d,p) and M06-2X/6-31++G(d,p) levels of DFT. The computed structural parameters were compared with the data obtained by single crystal X-ray diffraction experiment. Chemical reactivity (electronegativity, electrophilicity, hardness, chemical softness and chemical potential) was predicted with the help of HOMO- LUMO energy values. Experimental FT-IR was recorded and the calculated values were also analyzed using the same level of DFT. A complete vibrational spectrum was made to analyze the potential energy distribution (PED). Stability of the molecule arising from hyperconjugative interaction was analyzed by the natural bond orbital (NBO) analysis. The molecular electrostatic potential map was used to detect the possible electrophilic and nucleophilic sites in ATN molecule. Cocrystallization of atenolol-hydrochlorothiazide (ATN-HCTZ) was performed and the structure was analyzed by powder X-ray diffraction. NBO analysis was carried out on the ATN-HCTZ cocrystal for the elucidation of inter and intra-molecular hydrogen bonding interactions in the structure. Atenolol interaction with human serum albumin (HSA) was investigated by a molecular docking study.