Synthesis,computational, experimental antimicrobial activities and theoretical molecular docking studies of (E)-4-((4-hydroxy-3-methoxy-5-nitrobenzylidene) amino)-N-(thiazole-2-yl) benzenesulfonamide

The compound (E)-4-((4-hydroxy-3-methoxy-5-nitrobenzylidene) amino)-N-(thiazole-2-yl) benzene sulfonamide (5NVTH) was synthesized and characterized by the Infrared, UV-Visible, and NMR analysis. The compound theoretical study was done by using DFT. The compound molecular structure and geometry were defined using DFT. Topological studies, like ELF, LOL, ALIE, and RDG studies, were done with the Multiwfn-3.8 to find the main binding areas and weak interactions in the molecule. Using the IEFPCM solvation model was used to study the calculated UV-Visible spectrum. The HOMO-LUMO, MEP, and NBO properties were carried out in the gas phase. The NBO calculations are used to study how charges move between and within the molecule and the stability of this molecule. A pharmacological analysis is done using an online tool like Swiss-ADME, to see if the molecule could be a potential drug candidate; this evaluation looks at the drug-likeness, ADME, and eco-friendly toxicity properties of the 5NVTH molecule. Auto-dock suite is used for molecular docking study and discovery studio is used for analyzing the docking results. Antimicrobial activity studies indicate the compound Klebsiella pneumonia and Candida albicans have good antibacterial and antifungal activity compared to positive control and other microorganisms.     

Photophysical properties of (E)-4-((1-phenylethylidene)amino)-N-(pyrimidin-2-yl) benzenesulfonamide; synthesis,characterization, wavefunction and docking studies

The (E)-4-((1-phenylethylidene)amino)-N-(pyrimidin-2-yl) benzenesulfonamide (ACEDA) were synthesized and characterized by the Infrared, UV–Visible, and NMR analysis. Using density functional theory, the current work is a set of theoretical studies on ACEDA. The compound molecular structure and geometry were defined using DFT. Topological studies, like ELF, LOL, ALIE, and RDG studies, were done with the Multiwfn-3.8 to find the main binding areas and weak interactions in the molecule. Using the IEFPCM solvation model were used to study the calculated UV–Visible spectrum. The HOMO-LUMO, MEP, and NLO properties were carried out using DFT/B3LYP/cc-pVDZ basis set. The NBO calculations are used to study how charges move between and within the molecule and stability of this molecule. A pharmacological analysis is done using online tool like Swiss-ADME, to see if the molecule could be potential drug candidate; this evaluation looks at the drug-likeness, ADME and eco-friendly toxicity properties of the ACEDA molecule. Auto-dock suite and Discovery studio Visualizer are used to do molecular docking.     

Synthesis,computational, molecular docking studies and photophysical properties of (Z)-N-(pyrimidin-2-yl)-4-(thiophen-2-ylmethylene)amino) benzenesulfonamide

The (Z)-N-(pyrimidin-2-yl)-4-(thiophen-2-ylmethylene)amino) benzenesulfonamide (TH2DA) were synthesized and characterized by the Infrared, UV–Visible, and NMR analysis. Using density functional theory, the current work is a set of theoretical studies on TH2DA. The compound molecular structure and geometry were defined using DFT. Topological studies, like ELF, LOL, ALIE, and RDG studies, were done with the Multiwfn-3.8 to find the main binding areas and weak interactions in the molecule. Using the IEFPCM solvation model were used to study the calculated UV–Visible spectrum. The HOMO-LUMO, MEP, and NLO properties were carried out in the gas phase. The NBO calculations are used to study how charges move between and within the molecule and stability of this molecule. A pharmacological analysis is done using online tool like Swiss-ADME, to see if the molecule could be potential drug candidate; this evaluation looks at the drug-likeness, ADME and eco-friendly toxicity properties of the TH2DA molecule. Auto-dock suite and Discovery studio Visualizer are used to do molecular docking studies.     

Synthesis,characterization, computational,excited state properties,wave function,and molecular docking studies of (E)-4-((2-hydroxybenzylidene)amino)N-(thiazol-2-yl) benzenesulfonamide

The compound (E)-4-((2-hydroxybenzylidene)amino)N-(thiazol-2-yl) benzene sulfonamide (SATH) was synthesized and characterized by the Infrared, UV–Visible, and NMR analysis. Using density functional theory, the current work is a set of theoretical studies on SATH. The compound molecular structure and geometry were defined using DFT. Topological studies, like ELF, LOL, ALIE, and RDG studies, were done with the Multiwfn-3.8 to find the main binding areas and weak interactions in the molecule. Using the IEFPCM solvation model was used to study the calculated UV–Visible spectrum. The HOMO-LUMO, MEP, and NLO properties were carried out DFT/B3LYP/cc-pVDZ basis set in the gas phase. The NBO calculations are used to study how charges move between and within the molecule and the stability of this molecule. A pharmacological analysis is done using an online tool like Swiss-ADME, to see if the molecule could be a potential drug candidate; this evaluation looks at the drug-likeness, ADME, and eco-friendly toxicity properties of the PFPT molecule. Auto-dock suite and Discovery studio Visualizer are used to do molecular docking against 6ZZB protein.     

Synthesis,characterization, computational,excited state properties,wave function and molecular docking studies of (E)-1-(perfluorophenyl)-N-(p-tolyl) methanimine

The compound (E)-1-(perfluorophenyl)-N-(p-tolyl)methanimine (PFPT) was synthesized and characterized by the Infrared, UV–Visible, and NMR analysis. Using density functional theory, the current work is a set of theoretical studies on PFPT. The compound molecular structure and geometry were defined using DFT. Topological studies, like electron localized function, localized orbital locator, average localized ionization energy, and reduced density gradient studies, were done with the Multiwfn-3.8 to find the main binding areas and weak interactions in the molecule. Using the IEFPCM solvation model used to study the calculated UV–Visible spectrum, we used two different solvents. The HOMO-LUMO, MEP, and NLO properties were carried out by DFT/B3LYP/cc-pVDZ in the gas phase. The NBO calculations are used to study how charges move between and within the molecule and the stability of this molecule. A pharmacological analysis is done using an online tool like Swiss-ADME, to see if the molecule could be a potential drug candidate; this evaluation looks at the drug-likeness, ADME, and eco-friendly toxicity properties of the PFPT molecule. Auto-dock suite and Discovery studio Visualizer are used to do molecular docking against 2QFA protein.     

Synthesis,structural, computational,electronic spectra,wave function properties and molecular docking studies of (Z)-4-(((5-methylfuran-2-yl)methylene)amino)-N-(thiazol-2-yl)benzenesulfonamide

The (Z)-4-(((5-methylfuran-2-yl) methylene)amino)-N -(thiazol-2-yl) benzene sulfonamide (5M2FTH) was synthesized and characterized by the Infrared, UV–Visible, and NMR analysis. Using density functional theory, the current work is a set of theoretical studies on 5M2FTH. The compound molecular structure and geometry were defined using DFT. Topological studies, like ELF, LOL, ALIE, and RDG studies, were done with the Multiwfn-3.8 to find the main binding areas and weak interactions in the molecule. UV spectra was simulated using TD-DFT with implicit solvation model. The HOMO-LUMO, MEP, and NLO properties were carried out in the gas phase. The NBO calculations are used to study how charges move between and within the molecule and stability of this molecule. Pharmacological analysis was performed using Swiss-ADME and found that the compound is a potential drug candidate. PASS analysis revealed that the molecule can show antiparasitic properties which is confirmed by molecular docking against the target protein.     

Identification of critical chemical features for Aurora kinase-B inhibitors using Hip-Hop, virtual screening and molecular docking

This study was performed to find the selective chemical features for Aurora kinase-B inhibitors using the potent methods like Hip-Hop, virtual screening, homology modeling, molecular dynamics and docking. The best hypothesis, Hypo1 was validated toward a wide range of test set containing the selective inhibitors of Aurora kinase-B. Homology modeling and molecular dynamics studies were carried out to perform the molecular docking studies. The best hypothesis Hypo1 was used as a 3D query to screen the chemical databases. The screened molecules from the databases were sorted based on ADME and drug like properties. The selective hit compounds were docked and the hydrogen bond interactions with the critical amino acids present in Aurora kinase-B were compared with the chemical features present in the Hypo1. Finally, we suggest that the chemical features present in the Hypo1 are vital for a molecule to inhibit the Aurora kinase-B activity.     

A comparative study of key properties of glycine glycinium picrate (GGP) and glycinium picrate (GP): A combined experimental and quantum chemical approach

Using experimental and computational techniques, a comparative study of electro-optical properties for glycine glycinium picrate (GGP) and glycinium picrate (GP) compounds has been performed. The single crystal of GGP has been grown using slow evaporation technique that was further subjected to experimental characterization of its electro-optical properties. The good optical transparency and mechanical strength at micro level was confirmed from optical and nanoindentation measurements using the Oliver–Pharr method of the grown single crystals. Differential scanning calorimetric (DSC) analysis was done to probe the thermal stability of the grown single crystals. Using the density functional theory (DFT) methods, we have not only investigated the GGP but also proposed GP molecule. Additionally, we have shed light on the molecular geometries, infrared and Raman spectra, linear and nonlinear optical properties of both GGP and GP at molecular level. The time dependent DFT (TD-DFT) approach was adopted to calculate the excitation energies of the molecules in different phases including gas, water, acetone, cyclohexane and chloroform as well. For GGP, its wavelength of maximum absorption is calculated to be ～390 nm at B3LYP/6-31G¹ level of theory. The calculated amplitudes of first hyperpolarizability (β_tot) for GGP and GP are found to be 712 and 970 a. u., respectively, which are about 16 and 23 times larger than that of the urea molecule (a prototype NLO molecule). Thus the present study not only brings to limelight the optical and nonlinear optical properties of GGP but also sheds light on the possible potential of GP as new NLO molecule.     

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.     

Insights into the binding mechanism of 2,5-substituted 4-pyrone derivatives as therapeutic agents for fused dimeric interactions: A computational study using QTAIM,dynamics and docking simulations of protein–ligand complexes

The study is focused on examining 2,5-Substituted 4-Pyrone based compounds through quantum chemical and topological analysis techniques, evaluating the properties of these compounds, including their geometrical structure, intermolecular interactions and assess their possible applications. Additionally, the molecular stability, charge delocalization and UV-Visible data was investigated and compared with the calculated energy and oscillator strength using the TD-DFT approach. The researchers observed that charge transfer occurred within the molecule, indicated by the HOMO and LUMO energies. It was also found that the compound exhibited planarity and higher chemical reactivity. The calculated Mulliken charges and molecular electrostatic potential were used to interpret the Fukui index data that help predict reactive sites and understand the reactivity patterns of specific atoms in a compound. The study is aimed to understand the role of NCI in the molecule under investigation using electron localization functions and localized orbit locator methods. Molecular docking and ADMET studies were conducting involving a detailed MD simulation of a protein-ligand complex using the OPLS3e force field and the SPC water model. These findings could prove to be beneficial in developing new therapeutic agents with various pharmacological effects and potential toxicities.     

Electronic absorption,vibrational spectra,non-linear optical properties,NBO analysis and thermodynamic properties of 9-[(2-hydroxyethoxy) methyl] guanine molecule by density functional method

The Fourier transform infrared (FT-IR) and FT-Raman of 9-[(2-hydroxyethoxy) methyl] guanine (9-2HEMG) have been recorded in the regions 4000–100 and 4000–400 cm⁻¹, respectively. A complete assignment and analysis of the fundamental vibrational modes of the molecule were carried out. The observed fundamental modes have been compared with the harmonic vibrational frequencies computed using DFT (B3LYP) method by employing 6-31G(d,p) and 3-21G basis sets. The vibrational studies were interpreted in terms of potential energy distribution. The first order hyperpolarizability (β₀) and related properties (α, μ and Δα) of this molecular system are calculated using B3LYP/6-31G(d,p) method based on the finite-field approach. Stability of the molecule arising from hyperconjugative interactions and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The results show that electron density (ED) in the σ* and π* antibonding orbitals and second-order delocalization energies (E(²⁾) confirm the occurrence of intramolecular charge transfer (ICT) within the molecule. UV–vis spectrum of the compound has been recorded and electronic properties such as excitation energies, oscillator strength and wavelength are calculated by TD-DFT and CIS methods using B3LYP/6-31G (d,p) basis set. Molecular electrostatic potential (MEP) and HOMO–LUMO energy levels are also constructed. The thermodynamic properties of the title compound have been calculated at different temperatures and the results reveal that the standard heat capacities (C_p,m), standard entropies (S_m) and standard enthalpy changes (H_m) increase with rise in temperature.     

Synthesis,spectral analysis,antibacterial activity,quantum chemical studies and supporting molecular docking of Schiff base (E)-4-((4-bromobenzylidene) amino)benzenesulfonamide

A new Schiff base (E)-4-((4-bromobenzylidene) amino) benzenesulfonamide (M2) was synthesized by the reaction between 4-bromobenzaldehyde and sulfanilamide followed by characterization using IR, Raman, UV–Visible, ¹HNMR, and ¹³CNMR spectral techniques. This was followed by electronic structure studies using DFT and TD-DFT. We simulated the IR spectrum using B3LYP/6-31+G(d,p) level of theory, followed by a comparison with experimental spectra and detailed potential energy distribution and vibrational assignment analysis. The comparison of experimental UV and simulated UV spectrum using TD-DFT B3LYP/6-31+G(d,p) in DMSO solvent atmosphere gave good agreement. As Schiff bases are biologically active, we checked for the potential activity of the synthesized compound with the help of ADMET prediction and found it to be active. Wavefunctions related properties like ELF, LOL, and ELF are also reported. Prediction of biological activity spectrum study indicated possible antibacterial activity against bacteria, which is supported by molecular docking against Staphylococcus aureus (3U2D) protein with a docking score of ?7.1 kcal/mol. Experimental antibacterial study using the compound and standard drugs confirmed this prediction.     

Free volume related fluorescent behavior in electron beam irradiated chalcone doped PVA

Effect of electron irradiation on the free volume related microstructural and optical properties of chalcone doped Poly(vinyl alcohol) composite films have been studied using FTIR, UV-Visible, XRD and Positron Annihilation techniques. The FTIR spectral study shows that the irradiation induces the crosslinking within the composite. Using UV-Visible absorption spectra the optical energy band gap and activation energies were estimated and the variation of these parameters suggests the existence of defects and molecular ordering within the irradiated composite. XRD diffractograms reveal that the crosslinking enhances the crystallinity of the sample. In this cross-linked polymer composite the fluorescence enhancement has been observed in the fluorescence spectral study. The Positron annihilation result suggests that the irradiation affects the free volume properties and crosslinking hinders the chalcone chromophore molecular rotation. Under this restricted condition the chromophore molecules likely to emit enhanced fluorescence and its mobility is directly related to the free volume around it.     

Synthesis and characterization of metal(II) complexes of poly(3-nitrobenzylidene-1-naphthylamine-co-succinic anhydride)

The alternating copolymer poly(3-nitrobenzylidene-1-naphthylamine-co-succinic anhydride) was synthesized from the Schiff base, 3-nitrobenzylidene-1-naphthylamine and succinic anhydride using hydroquinone monomethyl ether under nitrogen atmosphere. The molecular weight of the copolymer was determined by gel permeation chromatography. The metal-polymer complexes were synthesized by the reaction of THF solution of the alternating copolymer with aqueous solution of Cu(II) and Ni(II) acetates. The elemental analysis of the metal-polymer complexes suggests that the metal to ligand ratio is 1:2. The IR spectral data indicate that the metal ions are coordinated through the oxygen of the keto and ester groups. The UV-Visible, magnetic moments and ESR studies indicate square planar geometry for Cu(II) and distorted octahedral geometry for Ni(II) complexes. XRD studies revealed that the copolymer and its Cu(II) complex are crystalline, while the Ni(II) complex is amorphous. The intrinsic viscosity of the copolymer, thermal properties of metal-polymer complexes and their catalytic activity are discussed.     

Synthesis,Spectroscopic Studies and Keto-Enol Tautomerism of Novel 1,3,4-Thiadiazole Derivative Containing 3-Mercaptobutan-2-one and Quinazolin-4-one Moieties

In this study, a novel 1,3,4-thiadiazole derivative containing 3-mercaptobutan-2-one and quinazolin-4-one moieties (Compound 3) is synthesized by the coupling of 2-amino-1,3,4-thiadiazole-5-(3-mercaptobutan-2-one) (Compound 1) with 2-Phenyl-4H-3,1-benzoxazin-4-one (Compound 2) in one molecule moiety. Compound 3 is found to exist as two types of intra-molecular hydrogen bonding with keto-enol tautomerism characters, which is further confirmed using FTIR, ¹H-NMR, ¹³C-NMR, mass spectrometer, and UV-Visible spectra. The ¹H-NMR and UV-Visible spectra of Compound 3 are investigated in different solvents such as methanol, chloroform, and DMSO. Compound 3 exhibits keto-enol tautomeric forms in solvents with different percentage ratios depending on the solvent polarity. The ¹H-NMR and UV-Visible spectral results show that Compound 3 favors the keto over the enol form in polar aprotic solvents such as DMSO and the enol over the keto form in non-polar solvents such as chloroform. The ¹³C-NMR spectrum gives two singles at δ 204.5 ppm, due to ketonic carbon, and δ 155.5 ppm, due to enolic carbon, confirming the keto-enol tautomerism of Compound 3. Furthermore, the molecular ion at m/z 43 and m/z 407 in the mass spectrum of Compound 3 and fragmentation mechanisms proposed reveal the existence of the keto and enol forms, respectively.     

Design,synthesis and computational evaluation of a novel intermediate salt of N-cyclohexyl-N-(cyclohexylcarbamoyl)-4-(trifluoromethyl) benzamide as potential potassium channel blocker in epileptic paroxysmal seizures

The narrow therapeutic range and limited pharmacokinetics of available Antiepileptic drugs (AEDs) have raised serious concerns in the proper management of epilepsy. To overcome this, the present study attempts to identify a candidate molecule targeting voltage gated potassium channels anticipated to have superior pharmacological than existing potassium channel blockers. The compound was synthesized by reacting (S)-(+)-2,3-dihydro-1H-pyrrolo[2,1-c][1,4] benzodiazepine5,11(10H,11aH)-dione with 4-(Trifluoromethyl) benzoic acid (C₈H₅F₃O₂) in DMF and N,N′-dicyclohexylcarbodiimide (DCC) which lead to the formation of an intermediate salt of N-cyclohexyl-N-(cyclohexylcarbamoyl)-4-(trifluoromethyl)benzamide with a perfect crystalline structure. The structure of the compound was characterized by FTIR, ¹H NMR and ¹³C NMR analysis. The crystal structure is confirmed by single crystal X-ray diffraction analysis. The Structure-Activity Relationship (SAR) studies revealed that substituent of fluoro or trifluoromethyl moiety into the compound had a great effect on the biological activity in comparison to clinically used drugs. Employing computational approaches the compound was further tested for its affinity against potassium protein structure by molecular docking in addition, bioactivity and ADMET properties were predicted through computer aided programs.     

Synthesis,characterization, spectroscopy,X-ray structure and gaussian hybrid computational investigation of (−)-(S)-1-[2-(benzenesulfonamido)-3-phenylpropanoyl]-4-[(4-methyl)phenyl]thiosemicarbazide

Abstract

The molecule (?)-(S)-1-[2-(benzenesulfonamido)-3-phenylpropanoyl]-4-[(4-methyl)phenyl] thiosemicarbazide was synthesized and its structure analyzed by X-ray diffraction to understand its geometry, and inter/intra-molecular interactions. Theoretical calculations were carried out using DFT and TD-DFT methods with B3LYP/6-31G(d, p) and B3LYP/6-31G?+?(d, p) basis sets. Theoretical bond parameters, harmonic vibration frequencies, and chemical shifts are in good agreement with the experimental results. Electronic properties of the molecule derived from frontier orbitals, molecular electrostatic potential, and theoretical UV-Visible spectrum are validated experimentally.