Synthesis, spectroscopic (13C/1H-NMR, FT-IR) investigations, quantum chemical modelling (FMO, MEP, NBO analysis), and antioxidant activity of the bis-benzimidazole molecule

The role of biochemical and biophysical properties, molecular docking and dynamics studies on azelastine

The structure of the 4-(4-chlorobenzyl)-2-(1-methylazepan-4-yl) phthalazin-1(2H)-one (IA) was optimized through computational study. The optimized structure revealed that the bond length between atoms C3 and C5 was the longest at 1.54 Å, while the bond between atoms C10 and H31 had the lowest length at about 1.01 Å, respectively. The natural bond orbital (NBO) analysis indicates that the bonding π(C3-C20) to anti-bonding π∗(N2-C3) interaction exhibits the most significant stabilization energy of about 253.59 kcal/mol. Due to the solvent's influence, the gas phase MEP value and HOMO-LUMO band gap value are lower, when compared to solvents. A localized bond pair that undergoes movement between two atoms, and a bond pair that undergoes movement between two different pairs of atoms are identified by electron localized function (ELF), localized orbital locator (LOL), and average localized ionization energy (ALIE) studies, respectively. The electron density and thermodynamic properties were determined using Gaussian software. This study examined various parameters such as non-linear optical (NLO), molecular electrostatic potential (MEP), UV-vis, and HOMO-LUMO in different solvents. Further, the biological activity of the IA compound was studied using molecular docking and dynamics on the target Mycobacterium tuberculosis ArgF (7NOR) protein, which showed favorable protein-ligand interaction energy.

Investigating the molecular interactions of two long-chain PFASs with human serum albumin: Insights from multispectral analysis and computational methods

Long-chain perfluoroalkyl substances (FPAS) are commonly detected in environmental and biological contexts. This study investigated the interactions of perfluoroundecanoic acid (PFUnDA) and perfluorotridecanoic acid (PFTrDA) with human serum albumin (HSA). Fluorescence quenching experiments demonstrated static quenching of HSA's intrinsic fluorescence by both PFUnDA and PFTrDA, resulting in the formation of stable HSA-PFAS complexes. At 298 K, PFUnDA exhibited a higher binding constant (5.50 × 107 L/mol) than PFTrDA (1.01 × 105 L/mol), indicating stronger binding affinity. Thermodynamic analysis indicated that hydrogen bonds and van der Waals forces were the predominant interactions in the binding processes. Molecular docking confirmed that both PFASs bind to the IIA subdomain of HSA, with PFUnDA exhibiting lower binding energy (-8.690 kcal/mol) than PFTrDA. Molecular dynamics simulations further supported these findings, with PFUnDA showing stronger binding energy (-13.894 kcal/mol) driven primarily by van der Waals forces and electrostatic interactions. Quantum chemical analysis reveals that the carbonyl groups in PFUnDA and PFTrDA exhibit significant molecular reactivity, indicating a propensity for more vigorous chemical interactions. This study not only reveals the potential biological activity of PFUnDA and PFTrDA, but also provides scientific basis for evaluating their biosafety and risks.

DFT Study of Interaction between Teriflunomide and β-cyclodextrin

INTRODUCTION

This study employs Density Functional Theory (DFT) to investigate the interactions between Teriflunomide and β-cyclodextrin in the gas phase.

METHODS

The non-bonded interaction effects of the Teriflunomide compound with β-cyclodextrin on the chemical shift tensors, electronic properties, and natural charge were also observed. An analysis of the natural bond orbital (NBO) indicated that the molecule β-cyclodextrin as an electron donor functions while Teriflunomide functions as an electron acceptor in the complex β-cyclodextrin/Teriflunomide.

RESULTS

The electronic spectra of the Teriflunomide drug and complex β-cyclodextrin/ Teriflunomide were calculated by Time-Dependent Density Functional Theory (TDDFT) to investigate the adsorption effects of the Teriflunomide drug over β-cyclodextrin on maximum wavelength.

CONCLUSION

As a result, the possibility of the use of β-cyclodextrin for Teriflunomide delivery to the diseased cells has been established.

Network analysis and molecular modeling studies of pinocembrin a bioactive phytochemical of Dodonaea viscosa against Parkinson's disease

Parkinson's disease, a neurodegenerative disorder, is quickly progressing and accounts for 15% of dementia cases. Parkinson's disease is the second most frequent form of neuronal degeneration after Alzheimer's, with an average age of 55 years for individuals exhibiting neuropsychiatric and physiological symptoms. Due to the effectiveness, low toxicity, and low side effects, bioactive compounds from plants have received increased attention recently as therapeutic drugs. In the current study, effective anti-neurodegenerative phytochemicals from Dodonaea viscosa were screened using in silico methods and have been proposed to be further investigated for the treatment of Parkinson's disease. The structures of twenty bioactive chemicals were screened and graph theoretical network analysis revealed alpha-synuclein as a potent therapeutic target. Based on docking scores, an effective bioactive molecule was selected, and its energy values, electrostatic potential surface and drug-like qualities were examined using molecular orbitals, pharmacokinetics and toxicity studies. Pinocembrin was found as a superior binder based on molecular docking as it demonstrated stronger binding with - 10.2 kcal/mol. An investigation using Ramachandran plot validated the protein-ligand complex secondary structure's stability. Pinocembrin, a bioactive phytochemical from Dodonaea viscosa, may be a viable lead molecule that may be developed as a candidate medicine for anti-neurodegenerative therapy against Parkinson's disease.

In-silico optimization of resveratrol interaction with nano-borophene: A DFT-guided study of supramolecular artistry

In this study, the potential of borophene (BOR) as a drug delivery system for resveratrol (RVT) was explored to evaluate its efficacy in cancer treatment. The excited, electronic, and geometric states of RVT, BOR, and the borophene-adsorbed resveratrol complex (BOR@RVT) were calculated to assess BOR's suitability as a drug carrier. Noncovalent interaction (NCI) plots indicated a weak force of attraction between BOR and RVT, which facilitates the offloading of RVT at the target site. Frontier molecular orbital (FMO) analysis showed that during electron excitation from Highest Occupied Molecular Orbital (HOMO) to Lowest Unoccupied Molecular Orbital (LUMO), charge transfer occurs from RVT to BOR. This was further confirmed by charge decomposition analysis (CDA). Calculations for the excited state of BOR@RVT revealed a red shift in the maximum absorption wavelength (λmax), indicating a photoinduced electron transfer (PET) process across various excited states. PET analysis demonstrated fluorescence quenching due to this interaction. Our findings suggest that BOR holds significant potential as a drug delivery vehicle for cancer treatment, offering a promising platform for the development of advanced drug delivery systems.

Elucidation of the Microwave-Assisted Synthesis and Characterization of Heteronuclear Complexes of Bisbenzimidazole Derivatives and Their Biological Activities by In Vitro and In Silico Assays

A novel and efficient protocol for the microwave-assisted synthesis of diversely substituted 2,2'-bisbenzimidazol-5,6'-dicarboxylic acid (BIMCA) from the reaction of 3,4-diaminobenzoic acid with oxalic acid has been developed, which proceeds through sequential nucleophilic addition and electrophilic substitution in accordance with the Philips method. The synthetic utility of this strategy was demonstrated by the concise, one-pot synthesis of (BIMCA) and metal complexes. (BIMCA) with a [{Fe(salen)}2O] Schiff base ligand complex and new benzimidazole coordination compounds with double oxygen [(BIMCA){Fe(salen)}2] ligand complexes were obtained. The resulting [(BIMCA){Fe(salen)}2] ligand complex was then synthesized from Co(CH3COO)2.4H2O, Ni(CH3COO)2.4H2O and Cu(CH3COO)2.H2O heteronuclear complexes. The condensations proceed with good yield to give products that, in certain instances, are not readily attainable by conventional condensation techniques. The structures of the compounds were identified by Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), elemental analysis and magnetic susceptibility. The mutagenic potential of the synthesized chemicals was evaluated by the Ames test towards mutant Salmonella typhimurium strains TA98 and TA100. It was recorded that these chemicals had no mutagenic action. Also, antimicrobial activities were screened by broth microdilution test. It was seen that the minimum inhibitory concentration (MIC) against Klebsiella pneumoniae, Staphylococcus aureus and Staphylococcus epidermidis was 0.195 mg/mL, followed by a MIC value of 0.390 mg/mL against Escherichia coli and Salmonella typhimurium. [(BIMCA){Fe(salen)}2Co(II)] demonstrated significant antimicrobial activity against Proteus mirabilis and Staphylococcus aureus, with an MIC of 0.195 mg/mL, followed by an MIC of 0.390 mg/mL against Pseudomonas aeruginosa, K. pneumonia and Salmonella typhimurium. The antioxidant properties were examined using various chemical assays, and [(BIMCA){Fe(salen)}2O] and (BIMCA) exhibited greater 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability, when compared with other compounds. Enzyme inhibitory effects were tested against acetylcholinesterase (AChE), amylase, butyrylcholinesterase (BChE) and tyrosinase. [(BIMCA){Fe(salen)}2Cu(II)] displayed the best AChE (IC50 0.51 mg/mL), BChE (IC50 0.51 mg/mL) and tyrosinase (IC50 1.52 mg/mL) inhibitory effects. Furthermore, molecular docking calculations were performed to gain insights into the interaction between [(BIMCA){Fe(salen)}2] and AChE, and between [(BIMCA){Fe(salen)}2Cu(II)] and amylase. Both compounds showed the potential inhibition of the protein targets.

Detection of paracetamol by a montmorillonite-modified carbon paste sensor: A study combining MC simulation, DFT computation and electrochemical investigations

This study aims to develop a suitable electrochemical electrode through the incorporation of potassium montmorillonite (MMTK10)clay into the carbon matrix for the direct and sensitive determination of paracetamol (PAR) in pharmaceutical formulations. Electrochemical characterization of the electrodes involves the use of techniques such as cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and differential pulse voltammetry (DPV). The results reveal that the voltammetric response of PAR is linear over a wide concentration range (1.0-15 μM), with a low detection limit of 0.46 μM. Analytically, PAR recovery results were around 94%, indicating that the developed electrode is highly suitable for PAR detection in pharmaceutical formulation. Additionally, density functional theory (DFT) is employed to investigate the reactivity of PAR and explain the interaction process of PAR on the electrode surface at different pH values. A Monte Carlo simulations model is developed to provide a deeper understanding of the adsorption mechanism, particularly to comprehend molecular interactions and preferential orientations of PAR with MMT fractions at the electrode surface. Reduced Density Gradient is calculated and discussed using techniques such as Multiwfn and Visualization of Molecular Dynamics. The developed CPE-MMTK10 sensor provided a simple preparation method, rapid response, high sensitivity, reproducibility, strong selectivity, and extended stability. Moreover, there is a good correlation between most parameters calculated by DFT and experimental results, thereby reinforcing the validity of the theoretical approach in this study.

Spectroscopic characterization, DFT, antimicrobial activity and molecular docking studies on 4,5-bis[(E)-2-phenylethenyl]-1H,1'H-2,2'-biimidazole

The newly synthesized imidazole derivative namely, 4,5-bis[(E)-2-phenylethenyl]-1H,1'H-2,2'-biimidazole (KA1), was studied for its molecular geometry, docking studies, spectral analysis and density functional theory (DFT) studies. Experimental vibrational frequencies were compared with scaled ones. The reactivity sites were determined using average localized ionization analysis (ALIE), electron localized function (ELF), localized orbital locator (LOL), reduced density gradient (RDG), Fukui functions and frontier molecular orbital (FMO). Due to the solvent effect, a lower gas phase energy gap was observed. Through utilization of the noncovalent interaction (NCI) method, the hydrogen bond interaction, steric effect and Vander Walls interaction were investigated. Molecular docking simulations were employed to determine the specific atom inside the molecules that exhibits a preference for binding with protein. The parameters for the molecular electrostatic potential (MESP) and global reactivity descriptors were also determined. The thermodynamic characteristics were determined through calculations employing the B3LYP/cc-pVDZ basis set. Antimicrobial activity was carried out using the five different microorganisms like Escherichia coli, Streptococcus pneumoniae, Staphylococcus aureus, Klebsiella pneumoniae and Candida albicans.

Comparison study (experimental and theoretical), hydrogen bond interaction through water, donor acceptor investigation and molecular docking study of 3,3-((1,2-phenylenebis (azaneylylidene)) bis (methaneylylidene)) diphenol

The novel Schiff's base (CS6) was synthesized and confirmed by various studies. The B3LYP/cc-pVDZ basis set was used for theoretical study and the results indicated that both the theoretical and experimental studies correlated well. The interaction energy of CS6-water complex calculated by using the local energy decomposition analysis was found to be -7.28 kcal/mol. The TD-TFT method was used for the calculation of electronic absorption spectrum. This study confirmed that the observed wavelength and the simulated wavelength in the electronic spectra were almost similar. The electrophilic and nucleophilic attacking sites of the titled compound were identified by using FMO and MEP studies. The highest stabilization energy (30.19 kcal/mol) formed by LP (2) O24 to anti-bonding σ*(C18-C19) was confirmed by the NBO study. The localized and delocalized electrons were confirmed by ELF and LOL studies. The hydrogen bond interaction as well as the physical and chemical properties of CS6 indicated that it showed a moderate similarity to the drugs. The docking study confirmed that the dehydro-L-gulonate decarboxylase inhibitor (1Q6O) could interact with CS6 compound with the binding energy of -5.26 kcal/mol.

Coumarin linked to 2-phenylbenzimidazole derivatives as potent α-glucosidase inhibitors

α-Glucosidase inhibitors have emerged as crucial agents in the management of type 2 diabetes mellitus. In the present study, a new series of coumarin-linked 2-phenylbenzimidazole derivatives 5a-m was designed, synthesized, and evaluated as anti-α-glucosidase agents. Among these derivatives, compound 5k (IC50 = 10.8 µM) exhibited a significant inhibitory activity in comparison to the positive control acarbose (IC50 = 750.0 µM). Through kinetic analysis, it was revealed that compound 5k exhibited a competitive inhibition pattern against α-glucosidase. To gain insights into the interactions between the title compounds and α-glucosidase molecular docking was employed. The obtained results highlighted crucial interactions that contribute to the inhibitory activities of the compounds against α-glucosidase. These derivatives show immense potential as promising starting points for developing novel α-glucosidase inhibitors.

Neuroprotection of Truncated Peptide IIAVE from Isochrysis zhanjiangensis: Quantum Chemical, Molecular Docking, and Bioactivity Studies

Parkinson's disease (PD) is a progressive neurodegenerative disorder of the elderly for which there is no cure or disease-modifying therapy. Mitochondrial dysfunction and oxidative stress play a central role in dopaminergic neurodegeneration in PD. Therefore, antioxidants are considered a promising neuroprotective approach. In in vivo activity studies, 6-OHDA-induced oxidative stress in SH-SY5Y cells was established as a model of PD for cellular experiments. IIAVE (Ile-Ile-Ala-Val-Glu) was derived from Isochrysis zhanjiangensis octapeptide (IIAVEAGC), which has a small molecular weight. The structure and antioxidant activity of IIAVE were tested in a previous study and proved to have good antioxidant potential. In this study, the chemical properties of IIAVE were calculated using quantum chemical methods, including frontier molecular orbital (FMO), molecular electrostatic potential (MEP), natural population analysis (NPA), and global reactivity properties. The interaction of IIAVE with Bcl-2 and DJ-1 was investigated using the molecular docking method. The results showed that IIAVE promoted the activation of the Keap1/Nrf2 pathway and up-regulated the expression of the superoxide dismutase 1 (SOD-1) protein by inhibiting the level of reactive oxygen species (ROS) in cells. In addition, IIAVE inhibits ROS production and prevents 6-OHDA-induced oxidative damage by restoring mitochondrial membrane potential. Furthermore, IIAVE inhibited cell apoptosis by increasing the Bcl-2/Bax ratio and inhibiting the activation of Caspase-9 and Caspase-3. Thus, IIAVE may become a potential drug for the treatment and prevention of PD.

Binding Affinity and Mechanism of Six PFAS with Human Serum Albumin: Insights from Multi-Spectroscopy, DFT and Molecular Dynamics Approaches

Per- and Polyfluoroalkyl Substances (PFAS) bioaccumulate in the human body, presenting potential health risks and cellular toxicity. Their transport mechanisms and interactions with tissues and the circulatory system require further investigation. This study investigates the interaction mechanisms of six PFAS with Human Serum Albumin (HSA) using multi-spectroscopy, DFT and a molecular dynamics approach. Multi-spectral analysis shows that perfluorononanoic acid (PFNA) has the best binding capabilities with HSA. The order of binding constants (298 K) is as follows: "Perfluorononanoic Acid (PFNA, 7.81 × 106 L·mol-1) > Perfluoro-2,5-dimethyl-3,6-dioxanonanoic Acid (HFPO-TA, 3.70 × 106 L·mol-1) > Perfluorooctanoic Acid (PFOA, 2.27 × 105 L·mol-1) > Perfluoro-3,6,9-trioxadecanoic Acid (PFO3DA, 1.59 × 105 L·mol-1) > Perfluoroheptanoic Acid (PFHpA, 4.53 × 103 L·mol-1) > Dodecafluorosuberic Acid (DFSA, 1.52 × 103 L·mol-1)". Thermodynamic analysis suggests that PFNA and PFO3DA's interactions with HSA are exothermic, driven primarily by hydrogen bonds or van der Waals interactions. PFHpA, DFSA, PFOA, and HFPO-TA's interactions with HSA, on the other hand, are endothermic processes primarily driven by hydrophobic interactions. Competitive probe results show that the main HSA-PFAS binding site is in the HSA structure's subdomain IIA. These findings are also consistent with the findings of molecular docking. Molecular dynamics simulation (MD) analysis further shows that the lowest binding energy (-38.83 kcal/mol) is fund in the HSA-PFNA complex, indicating that PFNA binds more readily with HSA. Energy decomposition analysis also indicates that van der Waals and electrostatic interactions are the main forces for the HSA-PFAS complexes. Correlation analysis reveals that DFT quantum chemical descriptors related to electrostatic distribution and characteristics like ESP and ALIE are more representative in characterizing HSA-PFAS binding. This study sheds light on the interactions between HSA and PFAS. It guides health risk assessments and control strategies against PFAS, serving as a critical starting point for further public health research.

Synthesis and Computational Exploration of Morpholine Bearing Halogenated Sulfonamides as Potential Tyrosinase Inhibitors

In the presented work, a new series of three different 4-((3,5-dichloro-2-[(2/4-halobenzyl)oxy]phenyl)sulfonyl)morpholines was synthesized and the structure of these compounds were corroborated by 1 H-NMR & 13 C-NMR studies. The in vitro results established all the three compounds as potent tyrosinase inhibitors relative to the standard. The Kinetics mechanism plots established that compound 8 inhibited the enzyme non-competitively. The inhibition constants Ki calculated from Dixon plots for this compound was 0.0025 μM. Additionally, computational techniques were used to explore electronic structures of synthesized compounds. Fully optimized geometries were further docked with tyrosinase enzyme for inhibition studies. Reasonably good binding/interaction energies and intermolecular interactions were obtained. Finally, drug likeness was also predicted using the rule of five (RO5) and Chemical absorption, distribution, metabolism, excretion, and toxicity (ADMET) characteristics. It is anticipated that current experimental and computational investigations will evoke the scientific interest of the research community for the above-entitled compounds.

Synthesis, Characterization, Antimicrobial, Density Functional Theory, and Molecular Docking Studies of Novel Mn(II), Fe(III), and Cr(III) Complexes Incorporating 4-(2-Hydroxyphenyl azo)-1-naphthol (Az)

This work synthesized three new CrAz₂, MnAz₂, and FeAz₂ complexes and investigated them using IR, mass, UV spectroscopy, elemental analysis, conductivity and magnetic tests, and thermogravimetric analysis. The azo-ligand, 4-(2-hydroxyphenylAzo)-1-naphthol (Az), couples with metal ions via its nitrogen (in -N=N- bonds) and oxygen (in hydroxyl group) atoms, according to the IR spectra of these complexes. Through thermal examination (TG/TGA), the number and location of water in the complexes were also determined. Density functional theory (DFT) theory is applied to ameliorate the structures of the ligand (Az) and metal complexes and analyze the quantum chemical characteristics of these complexes. The antifungal and antibacterial activity of the ligand and its complexes opposed to several hazardous bacteria and fungi was investigated in vitro. Metal complexes were discovered to have a higher inhibitory impact on some organisms than the free ligand. The MnAz₂ complex exhibited the best activity among the studied materials, whereas the CrAz₂ complex had the lowest. The compounds' binding affinity to the E. coli (PDB ID: 1hnj) structure was predicted using molecular docking. Binding energies were calculated by analyzing protein-substrate interactions. These encouraging findings imply that these chemicals may have physiological effects and may be valuable for a variety of medical uses in the future.

Host-guest coupling to potentially increase the bio-accessibility of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea by nanocarrier graphyne for brain tumor therapy, a comprehensive quantum mechanics study

This study aimed to explore the potential of Host-Guest coupling with Nanocarrier graphyne (GPH) to enhance the bioavailability of the drug 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (LUM) for brain tumor therapy. The electronic, geometric, and excited-state properties of GPH, LUM, and the graphyne@1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea-complex (GPH@LUM-complex) were studied using DFT B3LYP/6-31G** level of theory. The results showed that the GPH@LUM-complex was stable with negative adsorption energy (-0.20 eV), and there was good interaction between GPH and LUM in the solvent phase. The weak interaction forces between the two indicated an easy release of the drug at the target site. The Frontier Molecular Orbitals (FMO), Charge Density Analysis (CDA), and Natural Bond Orbital (NBO) analysis supported LUM to GPH charge transfer during complex formation, and the Reduced Density Gradient (RDG) isosurfaces identified steric effects and non-bonded interactions. UV-visible examination showed the potential of the GPH@LUM-complex as a drug carrier with a blue shift of 23 nm wavelength in the electronic spectra. The PET process analysis revealed a fluorescence-quenching process, facilitating systematic drug delivery. The study concluded that GPH had potential as a carrier for delivering LUM, and different 2D nanomaterials could be explored for drug delivery applications. The theoretical study's findings may motivate researchers to investigate the practical applications of GPH@LUM-complex in oncology.

Novel N-benzyl-2-oxo-1,2-dihydrofuro [3,4-d]pyrimidine-3(4H)-carboxamide as anticancer agent: Synthesis, drug-likeness, ADMET profile, DFT and molecular modelling against EGFR target

A novel compound N-benzyl-2-oxo-1,2-dihydrofuro [3,4-d]pyrimidine-3(4H)-carboxamide (DHFP) was synthesized by addition, rearrangement, and intramolecular cyclization reactions. The three-dimensional geometry of DHFP has been determined by density functional theory calculations in the gas phase. Thus, the geometrical properties of DHFP such as the bond lengths, bond angles, and dihedral bond angles have been determined in the optimized molecular configuration. Also, the HOMO-LUMO energies were calculated. The charge distribution of the DHFP has been calculated by Natural Population Analysis (NPA) approach. NMR and FTIR spectra were calculated and compared with their experimental corresponding to confirm the synthesis of the DHFP. The anticancer activities of the DHFP were also determined on human colon cancer (HT29) and prostate cancer (DU145) cell lines. Molecular docking studies of the DHFP with EGFR tyrosine kinase, which is responsible for cancer cell proliferation and growth, were performed and it was observed that docking interaction took place. The DHFP has the potential to be a drug, as it is determined that DHFP obeys Lipinski's five rules, can cross the blood-brain barrier, and can be rapidly absorbed from the gastrointestinal wall.

Synthesis, Molecular Docking, Dynamics, Quantum-Chemical Computation, and Antimicrobial Activity Studies of Some New Benzimidazole-Thiadiazole Hybrids

In this study, some new compounds, which are 2-aminothiadiazole derivatives linked by a phenyl bridge to the 2-position of the benzimidazole ring, were designed and synthesized as antimicrobial agents. The structures of the compounds were elucidated by ¹H and ¹³C NMR spectroscopy, high-resolution mass spectrometry, and elemental analysis. The antifungal activities of the synthesized compounds were tested on Candida albicans, Candida krusei, Candida glabrata, and Candida parapsilosis. Compound 5f is more active against C. albicans and C. glabrata than standard fluconazole and varicanazole. Compounds were also evaluated for their counteracting activity against Gram-positive Escherichia coli, Serratia marcescens, Klebsiella pneumoniae, and Pseudomonas aeruginosa and Gram-negative Enterococcus faecalis, Bacillus subtilis, and Staphylococcus aureus. Compounds 5c and 5h had minimum inhibitory concentrations against E. faecalis close to that of the standard azithromycin. Molecular docking studies were performed against Candida species' 14-α demethylase enzyme. 5f was the most active compound against Candida species, which gave the highest docking interaction energy. The stabilities of compounds 5c and 5f with CYP51 were tested using 100 ns molecular dynamics simulations. According to the theoretical ADME calculations, the profiles of the compounds are suitable in terms of limiting rules. HOMO-LUMO analysis showed that 5h is chemically more reactive (represented with the lower ΔE = 3.432 eV) than the other molecules, which is compatible with the highest antibacterial activity result.

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.