Experimental and theoretical investigation of mild steel corrosion control in acidic solution by Ranunculus arvensis and Glycine max extracts as novel green inhibitors.

In the present research, the ability of Ranunculus arvensis (RA) and Glycine max (GM) extracts as green corrosion inhibitors of mild steel (MS) in 1 M HCl was investigated. The inhibiting potential of RA and GM was analysed employing electrochemical impedance spectroscopy (EIS), polarization curves, potentiometry, and theoretical investigations. An enhancement in the inhibition efficiency (I.E) with increasing inhibitors concentrations indicated by EIS data and polarization curves. According to obtained results both extracts indicated inhibitory effect, with their effectiveness following the order of RA > GM. In addition, the interactions between the inhibitors on the MS surface were assessed using B3LYP/6-311g(d,p) theory level in liquid water phase. The interaction energies for three orientations of RA and GM depicted that inhibitors have located parallel to the alloy surface. The preferred complex orientation is one in which the maximum number of inhibitor donor atoms interacted with the alloy surface. Finally, experimental and theoretical results were in accordance which confirmed the inhibition effect of RA and GM extracts.

Computational modeling, fabrication, and characterization of the deep eutectic solvent-based green molecular cage for selective metronidazole extraction from plasma followed by UHPLC with diode array detector determination.

Four ternary deep eutectic solvents were computationally designed and synthesized, being used as candidate functional monomers in metronidazole molecular imprinting polymer synthesis, allowing selective extraction and determination by ultra high performance liquid chromatography with diode array detection. In terms of metronidazole selective extraction, the best results were obtained by (deep eutectic solvent)2 :(ethylene glycol dimethacrylate)11 , in which deep eutectic solvent is the functional monomer constructed by combining three components in 6:6:2 ratios of choline chloride:ethylene glycol:methacrylic acid. The effects of different parameters on molecular imprinted solid-phase extraction of metronidazole were thoroughly explored through screening design and response surface methodology. The adsorption mechanism findings show that the adsorption data are primarily fitted on the Freundlich model based on higher correlation coefficient. Kinetic experiments have shown that the mechanism of adsorption fits the pseudo-second-order model. The best extraction recovery (96.5%) was obtained in 25-min elution time, desorption temperature of 40°C, and 1.0 mL ACN as eluent. Metronidazole was measured by a validated ultra high performance liquid chromatography with diode array detection method. The calibration of the method was linear in the range of 0.1-10 µg/mL with limits of detection and quantification of 0.03 and 0.1 µg/mL, respectively. The method was successfully applied for the determination of metronidazole in human plasma.

Metronidazole aryloxy, carboxy and azole derivatives: Synthesis, anti-tumor activity, QSAR, molecular docking and dynamics studies.

A series of novel metronidazole aryloxy, carboxy and azole derivatives has been synthesized and their cytotoxic activities on three cancer cell lines were evaluated by MTT assay. Compounds 4m, 4l and 4d showed the most potent cytotoxic activity (IC50s less than 100 µg/mL). Apoptosis was also detected for these compounds by flow cytometry. Docking studies were performed in order to propose the probable target protein. In the next step, molecular dynamics simulation was carried out on the proposed target protein, focal adhesion kinase (FAK, PDB code: 2ETM), bound to compound 4m. As, 4m showed a potent cytotoxic activity and an acceptable apoptotic effect, it can be a potential anticancer candidate that may work through inhibition of FAK.

Computer-aided design and synthesis of a highly selective molecularly imprinted polymer for the extraction and determination of buprenorphine in biological fluids.

Buprenorphine is widely used to aid the cessation of opioids in addicted patients. To the best of our knowledge, there is no selective extraction method for buprenorphine from biological fluids. Here, we describe the synthesis of a molecularly imprinted polymer with the aid of computational design and its application for selective extraction of buprenorphine from plasma and urine. Computational design was used to study intermolecular interactions in the pre-polymerization mixture by the comparison of the binding energy between buprenorphine (template) and functional monomers. The largest interaction energy of template-monomers was obtained at ratio of 1:5 buprenorphine/acrylic acid monomers. Afterwards, the molecularly imprinted polymer was synthesized through precipitation polymerization technique and was employed for selective extraction of buprenorphine. Optimization of various parameters of the molecularly imprinted polymer solid-phase extraction of buprenorphine was carried out by a design of experiment approach using a central composite design and the analyte was determined by employing high-performance liquid chromatography with UV detection. Equilibrium isotherms were studied, and results revealed that the sorption process was in adoption with Langmuir model. Maximum enrichment capacity and Langmuir constant were calculated as 18.2 mg/g and 0.797 L/mg, respectively. Kinetic studies indicated the sorption process followed a pseudo-second-order model.

Computational study on transfer of L-ascorbic acid by UlaA through Escherichia coli membrane.

In this study, the transfer of L-ascorbic acid by UlaA through Escherichia coli (E. coli) membrane was evaluated using density functional theory (DFT), molecular docking, and molecular dynamics (MD) simulation methods. DFT calculations at the B3lyp/6[Formula: see text]311[Formula: see text]G(p,d) level were performed to investigate the interaction properties and molecular descriptors. The physical properties, such as chemical potential, chemical hardness, and chemical electrophilicity of all studied molecules, were investigated. Natural population analysis was employed to describe the state of charge transfer between interactions using the natural bond orbital (NBO). The atoms in molecules (AIM) theory was used to examine the properties of the bond critical points such as their electron densities and Laplacians. Molecular docking studies showed that L-ascorbic acid was bounded to the internal cavity of UlaA. It was found that there were some hydrogen bond interactions between L-ascorbic acid and active sites of UlaA. The results of the MD simulation showed that the root mean square deviation (RMSD) of UlaA and L-ascorbic acid bound-UlaA reached equilibrium after 3.7[Formula: see text]ns. An evaluation of the radius of gyration ([Formula: see text]) revealed that UlaA and L-ascorbic acid bound-UlaA were stabilized around 10,000[Formula: see text]ns. Finally, analysis of the RMS fluctuations suggested that the structure of the L-ascorbic acid binding site remained approximately rigid during simulation. All obtained results shed light on the special manner of L-ascorbic acid transfer through E. coli membrane, and confirmed the results of previous studies on this issue.

Effects of Displacement-Distortion of Potential Energy Surfaces on Nonadiabatic Electron Transfers via Conical Intersections: Application to SO2 and trans-1,3,5-Hexatriene.

We show that the time-correlation function formalism can be applied to calculate nonadiabatic electronic population dynamics on the two vibronically coupled diabatic displaced-distorted harmonic potential energy surfaces through conical intersection. We present general formulas for the time-evolved electronic populations at finite temperature with initial sampling from both initial thermal equilibrium and nonequilibrium nuclear distributions. The validity of our formalism is verified through comparison with previous work in a certain limit of our results for case of displaced harmonic oscillator. Finally for illustration, the derived expressions have been applied to determine the electronic population dynamics at conical intersections for SO2 and trans-1,3,5-hexatriene molecules.