BSA-binding studies of 2- and 4-ferrocenylbenzonitrile: voltammetric, spectroscopic and molecular docking investigations

The binding affinity of 2-ferrocenylbenzonitrile (2FBN) and 4-ferrocenylbenzonitrile (4FBN) with bovine serum albumin (BSA) has been investigated by cyclic voltammetry, absorption spectroscopy and molecular modelling techniques.  The results indicated that both of the two derivatives could bind to BSA and cause conformational changes with the order 2FBN > 4FBN. The voltammetric behavior of 2FBN and 4FBN before and after the addition of the BSA suggests that the redox process is kinetically controlled by the diffusion step, and demonstrated that the diffusion coefficients of the 2FBN-BSA and 4-FBN-BSA adducts are lower than that of the free compounds. Furthermore, molecular docking suggested that the binding mode of the two compounds to BSA is of hydrophobic and hydrogen bond interactions, moreover the ligand 2FBN additionally show a π-cation interaction.</p

Experimental and theoretical study on corrosion inhibition of mild steel by meso-tetraphenyl-porphyrin derivatives in acid solution

The inhibition effect of meso-tetraphenyl-porphyrin (TPPH2), meso-tetra4-methophenyl-porphyrin TPPH2(p-Me), and meso-tetra4-actophenyl-porphyrin (TAcPPH2) on the corrosion of XC52 mild steel in aerated 0.5 M aqueous sulfuric acid solution was studied by potentiodynamic polarization experiments and quantum chemical calculations. Results from potentiodynamic polarization showed that inhibition efficiency of three compounds increased upon increasing of the inhibitor concentration and they are acting as mixed type inhibitors, having dominant anodic reactions. Adsorption of all compounds follows the Langmuir adsorption isotherm with moderate values of free energy of adsorption. Quantum chemical calculation using DFT/B3LYP method confirmed a strong bond between meso-tetraphenyl-porphyrins and mild steel surface. The inhibition mechanism was also determined by the potential of zero charge (PZC) measurement at the metal/solution interface

Voltametric and molecular docking investigations of ferrocenylmethylaniline and its N-acetylated derivative interacting with DNA

N-ferrocenylmethylaniline (FA) and its N-acetylated derivative (NFA) have been synthesized and fully characterized by various physicochemical techniques such as 1H and 13C NMR spectroscopy, their interactions with chicken blood DNA (CB-DNA) were studied by cyclic voltammetry (CV) and molecular docking (MD). The obtained results suggested that both FA and NFA bind strongly via electrostatic interactions to the minor groove of double helix DNA,  these electrostatic interactions were evidenced by the findings like a negative formal potential shift in CV and ionic strength effect. The results further show that the obtained binding constants and free binding energies by MD analysis are matched roughly to those obtained from CV. Furthermore, the binding site size was evaluated from voltametric data

Rôle des transferts thermiques sur la corrosion des concentriques utilisés dans les puits producteurs d’eau albienne

L’eau de l’aquifère albien de la région de Haoud‑Berkaoui est utilisée à grande échelle et à des fins variées dans le Bas‑Sahara algérien, notamment dans le domaine de l’extraction pétrolière. Pour améliorer les conditions d’exploitation de l’eau souterraine, des concentriques ont été installés au sein des puits producteurs pour l’acheminement d’inhibiteurs de corrosion. La durée de vie de ces concentriques, prévue initialement pour cinq années, a été réduite à seulement deux ans, des fuites importantes d’eau ainsi que des dégradations au niveau des têtes de puits ayant été constatées.Les analyses chimiques des échantillons d’eau de plusieurs forages montrent que ces derniers sont de nature incrustante, chargés en sulfates, peu riches en gaz carbonique dissous et ne contiennent pas de H2S ni d’oxygène. Il a été possible, par thermométrie, de mettre en évidence l’existence d’un gradient de température, variable en fonction de la profondeur et pouvant atteindre 16 °C.La corrosion du concentrique sous transfert thermique a été examinée à l’aide des techniques électrochimiques. La vitesse de corrosion augmente considérablement en fonction du gradient de température croissant, quelle que soit la nature de l’eau (ayant ou non subi un traitement préalable par bactéricides et inhibiteurs). La meilleure efficacité des traitements employés a été obtenue pour un gradient nul et n’atteint que 30 %. L’absence totale de FeS élimine toute possibilité de corrosion d’origine bactérienne, le gradient de température semble favoriser l’accélération de la cinétique d’échange entre le métal et l’eau.The Haoud-Berkaoui region comprises three producing oil fields: Haoud-Berkaoui, Benkahla and Guellala, all located 100 km west of Hassi-Messaoud (Algéria). Oil is recovered from this heterogeneous medium sized layer by injecting water under pressure into the geological formations; the water is extracted from the Albien aquifer by 15 producing wells. To improve exploitation conditions and to increase injection capacities of this water, concentrics were installed within the producing wells to introduce anti-corrosion products. The life time of these facilities, initially predicted to be five years, has been reduced to only two years; important water leaks as well as deterioration of the wellheads have been noticed. The concentrics in the producing wells were in a very advanced state of corrosion, with apparent holes.Chemical analyses of water samples taken from several wells showed that their ion concentrations varied from 107 to 258 mg•L‑1 for calcium, 73 to 139 mg•L‑1 for magnesium, 24 to 36 mg•L‑1 for potassium, 282 to 304 mg•L‑1 for sodium, 459 to 648 mg•L‑1 for chlorides, while bicarbonate concentrations varied from 116  to 176 mg•L‑1. The water from these wells is generally hard, rich in sulphates, but poor in dissolved CO2 gas and lacking H2S and oxygen. The pH was neutral or slightly basic with values ranging between 7.02 and 7.58.A temperature gradient (∆T) was measured along the depth of the well, variable with depth, with a maximum gradient of 16 °C. The temperature gradient profile showed that ∆T was small at the surface of the well and then increased considerably at 584 m depth. For depths between 584 m and 984 m, ∆T was somewhat attenuated but remained high. It is in this zone that the concentric was most affected by corrosion.The corrosion of the concentric in an Albien medium under heat transfer was examined using electro-chemical techniques. The rate of corrosion increased sharply with increasing temperature, regardless of the water quality (i.e., treated with anti-bacterial or anti-corrosion agents, or not). These thermal effects are attributed to the acceleration of kinetic exchange reactions between the metal and the solution and are mainly linked to the energetic contribution associated with the heat flux crossing the concentric by conduction and convection.The efficiency of the anti-corrosion treatments was evaluated using the equation % E = 100 (Vcorr-V’corr)/Vcorr, where Vcorr and V’corr are the rates of corrosion with and without treatment, respectively. The best treatment efficiency of 30 % was obtained at a zero temperature gradient. The total absence of FeS eliminated the possibility of bacterial corrosion; the sulfato-reducing bacterium effect was eliminated by the bactericidal treatment

N-Ferrocenymethyl-N-phenyl­propionamide

In the title compound, [Fe(C5H5)(C15H16NO)], the two cyclo­penta­dienyl (Cp) rings are nearly parallel to each other, forming a dihedral angle of 3.7 (1)°, and adopt a staggered conformation. The amide group is almost perpendicular to the plane of the substituted Cp ring, with a C—N—C—C torsion angle of 101.3 (2)°, and the N and O atoms in the ethanoyl group are coplanar, with a C—N—C—O torsion angle of −0.7 (3)°. Weak C—H⋯O hydrogen bonds link adjacent mol­ecules

A novel ferrocenic copper(II) complex Salen-like, derived from 5-chloromethyl-2-hydroxyacetophenone and N-ferrocenmethylaniline: Design, spectral approach and solvent effect towards electrochemical behavior of Fc+/Fc redox couple

This paper reports the synthesis, spectroscopic characterizations and electrochemical behavior of the obtained tetradentate copper (II)-Schiff base complex with its two wings as ferrocenylaniline moieties. This new ferrocenic derivative with two ferrocenylaniline entities surrounding the copper (II)-Salen complex (5) was synthesized by reacting N-ferrocenmethyl-N-phenyl-5-aminomethyl-2-hydroxyacetophenone (3) with one half equivalent of 1,2-diaminoethane in absolute ethanol. As for the intermediates involved in this synthetic sequence, the compound (3) was prepared in tetrahydrofuran (THF) by reacting N-ferrocenmethylaniline (2) with 5-chloromethyl-2-hydroxyacetophenone (1) in presence of sodium hydrogenocarbonate (NaHCO3). The compound (3) condensed on the diamine yields the Schiff base ligand (4). Under a nitrogen atmosphere and stirring at 50 °C, the ligand dissolved in absolute ethanol with stoichiometric amount of copper acetate monohydrate (Cu(COOCH3)2·H2O) formed the expected tetradentate Cu(II)-Schiff base complex (5) after 6 h of reaction. All these synthesized compounds gave yields varying from 50 to 90%. Their purities were estimated from elemental analysis while the molecular structures were elucidated with FT-IR, UV–Vis, 1H- and 13C- NMR. For the obtained copper complex, it is tetracoordinated in a distorted square planar environment with two nitrogen and two oxygen atoms as donor sites. The electrochemical behaviors of the synthesized compounds were explored using cyclic voltammetry. This investigation showed an important anodic shifting of the Epc and Epa potential waves for the Fc+/Fc redox couple of compound (3) in dichloromethane (DC) medium, compared to other polar media like acetonitrile (AN), dimethylformamide (DMF) and dimethylsulfoxide (DMSO). This behavior was also observed for the tetradentate copper (II)-Salen complex with its different metallic centers.The authors would like to thank the MESRS and DG-RSDT (Ministère de l’Enseignement Supérieur et de la Recherche Scientifique et la Direction Générale de la Recherche et du Développement Technologique- Algérie) for their financial support. Financial support from the Ministerio de Economía y Competitividad (Spain) and FEDER funds (MAT2016-76595-R) is also gratefully acknowledged

Antidiabetic potential of mucilage fraction extracted from Astragalus gyzensis seeds

The objective of the current work is to extract a new mucilage fraction from Astragalus gyzensis Bunge. seeds, which are collected from the El-Oued province (septentrional Algerian Sahara) and evaluated for their antidiabetic potential. The mucilage fraction is obtained using hot water extraction followed by alcoholic precipitation of polysaccharides by cold ethanol (96%). The primary investigation was performed by describing the main structural features of the extract through colorimetric assays, Fourier-transform infrared spectroscopy and thin-layer chromatography analysis using two systems. Biological activity was also monitored by antidiabetic activity by testing the inhibition of α-amylase and α-glucosidase enzymes in vitro. The extraction yield was 20.69%. The chemical composition mainly consisted of 78.60±0.29% carbohydrates, among them 63.92±0.67% neutral sugar, 15.78±0.76% uronic acid, 8.08±0.04% proteins and 2.57±0.05% phenolic compounds. The results obtained by thin-layer chromatography analysis showed the dominance of mannose and galactose. Fourier-transform infrared spectrum showed characteristic bands expected galactomannans. The investigations highlighted the antihyperglycemic effect in a dose-dependent manner by the inhibition of the α-amylase enzyme (IC50=0.8±0.005 mg/mL). These factors make it suitable for the industrial application of dietary supplement fiber made for diabetic individuals. DOI: http://dx.doi.org/10.5281/zenodo.761853

N-ferrocenylmethyl-Derivatives As Spike Glycoprotein Inhibitors Of SARS-CoV-2 Using In Silico Approaches

Background and Objectives: By the end of 2019, a novel human coronavirus outbreak started in Wuhan and spread to the world becoming a global pandemic, patients were diagnosed with severe respiratory syndrome. Studies have shown that SARS-CoV2 interact with angiotensin-converting enzyme 2 (ACE2), its host cell receptor, by its Spike Glycoprotein. The aim of this study is to prevent this interaction by inhibiting Spike glycoprotein. Materials and Methods: The interaction of the Spike Glycoprotein of SARS-COV-2 extracted from protein data bank (PDB Code: 6VSB and 6LZG) with 10 different ferrocene derivatives ligands were investigated by performing docking studies using Autodock Tools 4.2. software. Results: The obtained results showed that N-ferrocenyl-methyl-3-nitroaniline was the best inhibitor ligand interacted with both proteins of coronavirus with the free binding energy equal to -5.38 and -6.65 Kcal/mol for 6VSB and 6LZG respectively with binding constant values equal to 8.7 × 103 and 72.72× 103respectively. Calculations revealed that the dominated mode of interaction for all the studied ligands with COVID-19 was the electrostatic mode via at least one H-bond and more than two hydrophobic Pi-Alkyl Bonds. Conclusion: Generally, the results indicated the existence of strong interactions between ligands and spike glycoprotein which prevent the virus to interact to ACE2 receptors.</p