Electrochemical, DFT and MD simulation of newly synthesized triazolotriazepine derivatives as corrosion inhibitors for carbon steel in 1 M HCl

The inhibitive action of three newly synthesized triazolotriazepine derivatives, namely, 9‑ethyl‑6‑methyl‑7H‑1,2,4‑triazolo[4,3‑b][1,2,4‑triazepin‑8(9H)-one (TTY), 7,9‑didecyl‑6‑methyl‑7H‑1,2,4‑triazolo[4,3-b][1,2,4]triazepin‑8‑one (TTY4), and 7,9‑ditetradecyl‑6‑methyl‑7H‑1,2,4‑triazolo[4,3‑b][1,2,4]triazepin‑8‑one (TTY5) for carbon steel in 1 M HCl is investigated using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS) and surface analysis techniques. The results show that the corrosion of carbon steel in HCl solution is efficiently inhibited by these new organic inhibitors. The adsorption of tested inhibitors on carbon steel surface is found to be spontaneous and obeyed the Langmuir adsorption isotherm. The anti-corrosion mechanism of these new inhibitors on iron was further revealed by quantum chemical calculations and molecular dynamics simulations. In agreement with the experimental data, theoretical results showed that the order of inhibition efficiency is TTY5 > TTY4 > TTY. © 201

Synthesis, spectroscopic characterizations, DFT, molecular docking and molecular dynamics simulations of a novel 2-methyl-3H-benzimidazolo[1,2-b][1,2,4]triazepin-4(5H)-one

A novel compound named 2-methyl-3H-benzimidazolo[1,2-b][1,2,4]triazepin-4(5H)-one (C11H10N4O) has been synthesized and characterized by spectroscopic techniques (FT-IR),UV–Vis,1H NMR, 13C NMR and mass spectra. The optimized molecular structure analyses, vibrational wave numbers, 13C and 1H NMR chemical shifts of the title molecule have been performed at DFT/B3LYP method with 6-31 + G(d,p) basis set. The electronic absorption wavelengths computed using B3LYP, B3P86 and PBE0 hybrid functional. The scaled vibrational modes, and the predicted 13C NMR and 1H NMR chemical shifts are relatively in good agreement with the corresponding experimental ones. However, B3LYP, B3P86 and PBE0 hybrid functional fail in reproduction of experimental λMAX of the tilted compound and it is underestimated by the tested hybrid functionals with deviations to the experimental values of 30, 34 and 40 nm for B3LYP, B3P86 and PBE0, respectively. In addition, molecular docking and molecular dynamics simulations of titled compound were carried out to determine its binding modes and stability within the leucine-rich repeat kinase 2 active site. © 2019 Elsevier B.V

Multidimensional insights involving electrochemical and: In silico investigation into the corrosion inhibition of newly synthesized pyrazolotriazole derivatives on carbon steel in a HCl solution

Herein, the anti-corrosion of carbon steel in 1 M HCl by two newly synthesized pyrazolotriazole derivatives, namely, 6-methyl-1H-pyrazolo[5,1-c][1,2,4]triazole-7-carbonitrile (CPT) and 1-acetyl-6-methyl-1H-pyrazolo[5,1-c][1,2,4]triazole-7-carbothioamide (MPT), was studied using electrochemical, density functional theory (DFT), and molecular dynamics (MD) simulation techniques. The experimental results showed that the concentrations of inhibitors had a significant influence on their inhibition efficiencies. Potentiodynamic polarization curves indicated that the two pyrazolotriazoles were mixed-type inhibitors. DFT calculations were employed to explore the molecular activity, and MD simulations were performed to obtain the interaction energy between the inhibitor molecules and the iron surface. The findings obtained using the theoretical calculation techniques were consistent with those obtained via experiments. © 2019 The Royal Society of Chemistry

Unexpected synthesis of novel 2-pyrone derivatives: crystal structures, Hirshfeld surface analysis and computational studies

Here we report synthesis of three new compounds namely, 1-acetyl-1H-benzimidazolo-2(3H)-one (I), N-(5-acetyl-6-methyl-2-oxo-2H-pyran-4-yl)-N-(2-acetamidophenyl)acetamide (II) and N-(2-acetamidophenyl)-N-2-oxo-2H-pyran-4-yl)acetamide (III) have been synthesized and characterized by single crystal X-ray diffraction. Compounds I and II crystallize in the monoclinic space groups P21/n, and P21/c, respectively, while III crystallizes in the triclinic space group P-1. The theoretical parameters of I–III have been calculated through density functional theory (DFT) by using the hybrid functional B3LYP and basis set 6-311++G**. These theoretical parameters have been compared with the experimental ones obtained by XRD. The significant intermolecular interactions arising in crystal packing are rationalized by means of the Hirshfeld surface analysis method. The major intermolecular contacts in the Hirshfeld surfaces of I–III are from H…H contacts. In addition, binding modes of I–III within Tyrosine-protein kinase JAK2 were investigated using molecular docking and molecular dynamics simulation studies. Communicated by Ramaswamy H. Sarma. © 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group

Synthesis, NMR characterization, DFT and anti-corrosion on carbon steel in 1M HCl of two novel 1,5-benzodiazepines

Benzodiazepines are known for their variety of applications. Herein, the corrosion inhibition efficiency on carbon steel in 1 M HCl solution in the presence and absence of two synthesized benzodiazepines 4-(2-Oxopropylidene)-1-propargyl-1,2,4,5-tetrahydro-3H-1,5-benzodiazepin-2-one (PTB) and 1-decyl-4-(2-oxopropylidene)-1,2,4,5-tetrahydro-3H-1,5-benzodiazepine-2-one (DTB) was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) methods at various concentrations from 10−3 to 10−6 K. The obtained structures were characterized using NMR spectroscopy. Potentiodynamic polarization measurements showed that 1,5-benzodiazepine derivatives act as a mixed type inhibitor. The various parameters of activation determining the kinetic data such as energy, enthalpy and entropy of the inhibitors were evaluated and discussed. The adsorptive behavior of PTB and DTB followed Langmuir-type isotherm. The standard free energies of adsorption were negative due to better inhibition performance. DFT calculations at the B3LYP/6-31 + G (d,p) level of theory in polarizable continuum model reveal that the high inhibition of efficiency of DTB compared with PTB may refer mainly to the easy electron transfer from the former to the carbon steel surface. © 2019 Elsevier B.V

A newly synthesized 6-methyl-7H,8H,9H-[1,2,4]triazolo[4,3-b][1,2,4]triazepin-8-one for potential inhibitor of adenosine A1 receptor: a combined experimental and computational studies

6-Methyl-7H,8H,9H-[1,2,4]triazolo[4,3-b][1,2,4]triazepin-8-onehas been synthesized, characterized by spectroscopic techniques (FT-IR, 1H and 13C NMR) and finally the structure was confirmed by single crystal X-ray diffraction studies. In the title molecule, C6H7N5O, the 7-membered ring adopts a bowl-like conformation. In the crystal, the molecules form stacks along the c-axis direction through offset π-stacking interactions between the 5-membered rings and C–H···N hydrogen bonds. The stacks are associated via a combination of N–H···N, C–H···O and C–H···N hydrogen bonds. Further, the Hirshfeld surface analysis reveals the nature of molecular interactions and the fingerprint plot provides information about the percentage contribution from each individual molecular contact to the surface. In addition, due to its biological interest the target molecule adenosine A1 receptor was found based on Structural Activity Relationship (SAR) analysis and, further, subjected into molecular docking and molecular dynamics analysis to understand the binding interaction and stability of the molecule in adenosine A1 receptor system. Furthermore, the Density Functional Theory (DFT) calculations were carried for free compound and the compound in active site (single point DFT), to know the internal stability. Communicated by Ramaswamy H. Sarma. © 2019, © 2019 Informa UK Limited, trading as Taylor & Francis Group

Synthesis, biological activity and molecular modeling of a new series of condensed 1,2,4-triazoles

A ring transformation of 6-methyl-7H[1,2,4]triazolo [4,3-b][1,2,4] triazepine-8(9H)-ones (thiones) in the presence of acetic anhydride give rise to a new series of 17 condensed 1,2,4-triazole derivatives (1–17). Plausible mechanisms are proposed and show the formation of a beta fused β-lactam moiety. The compounds were tested for their (i) inhibitory potential on digestive enzymes (α-amylase and α-glucosidase), and (ii) antioxidant activity using radical scavenging (DPPH and ABTS radicals) and ferric reducing power assays. The compounds showed interesting and promising antidiabetic activities compared to the reference drug Acarbose. Molecular docking study has been carried out to determine the binding mode interactions between these derivatives and the targeted enzymes. The results showed the strength of intermolecular hydrogen bonding in ligand-receptor complexes as an important descriptor in rationalizing the observed inhibition results. Moreover, molecular dynamics simulations are also performed for the best protein-ligand complex to understand the stability of small molecule in a protein environment. To shed light on the antioxidant activity of the synthesized compounds and the mechanism involved in DPPH free radical, DFT calculations were performed at the B3P86/6-311++G(d,p) level using the polarizable continuum model. The effect of aprotic solvent on bond dissociation enthalpies (BDEs) is investigated by calculating and comparing BDEs of 1 in methanol and dimethylsulfoxide as solvents using PCM. The obtained results show that the mechanism of action depends on the basic skeleton and the presence of substituted functional groups in these derivatives. BDEs are found to be slightly influenced by the aprotic solvent of less than 0.01 kcal/mol compared with those obtained in methanol. © 2019 Elsevier Inc

Phytochemical profiling, antimicrobial, antibiofilm, insecticidal, and anti-leishmanial properties of aqueous extract from Juglans regia L. root bark: In vitro and in silico approaches

The Juglans regia root aqueous extract (JRRAE) phytochemical variability and the investigation of their antimicrobial, antibiofilm, insecticidal, and anti-leishmanial properties were studied. As a result, the JRRAE chemical profile revealed the presence of biomolecules using UV, HPLC, and FT-IR analysis. The investigations showed marked antibacterial activities, highlighted inhibited biofilm formation, induced lethality Leishmania amazonensis promastigotes (50%), and possess an insecticidal activity at 100 µg/ml. A molecular docking study was performed against S. aureus gyrase, S. aureus tyrosyl-tRNA synthetase, human peroxiredoxin 5, cyclooxygenase-2, and trypanothione reductase and confirmed that the activities are mainly due to coumarin, epicatechin, juglone, epicatechin, and epicatechin presence, respectively. The stability of these complexes is essentially related to the strong hydrogen bonds formed between the most active compounds and the binding site amino acids. The identified compounds were found to pass the absorption, distribution, metabolism, and excretion property as well as five Lipinski’s rules with good drug-likeness and pharmacokinetic behavior. © 2023, Published with license by Taylor & Francis Group, LLC. © 2023 Ali Ellafi, Racha Farhat, Mejdi Snoussi, Emira Noumi, El Hassane Anouar, Ridha Ben Ali, Michèle Véronique El May, Sami Sayadi, Kaïss Aouadi, Adel Kadri and Sonia Ben Younes.Open Access funding provided by the Qatar National Library.Scopu