Solvents effect on the stability and reactivity of Tamoxifen and its nano metabolites as the breast anticancer drug

The effect of protic and aprotic solvents polarity on optimized geometry and some chemical reactivity indices for Tamoxifen (TAM) and three of its important metabolites, i.e. 3-hydroxy Tamoxifen (3-HTAM), Droloxifen, 4-hydroxy Tamoxifen (4-HTAM), Afimoxifen, and Z-N-desmethyl-4-hydroxy Tamoxifen, Endoxifen (ENDX), antitumor are studied theoretically by density functional theory calculations (B3LYP) with 6-311++G(d, p) basis set in combinationwith polarizable continuummodel (PCM) in selected non polar (CCl4), polar protic (H2O, Ethanol) and polar aprotic (DMSO, Acetone) solvents. The solvent-induced stretching vibrational frequency shifts (SFS) and the solvation influence on the DFT based chemical reactivity indices such as atomic charges, HOMOLUMO energies, stabilization energies, variation of dipole moment of the conformers, ionization potential, electron affinity, chemical potential, hardness and softness have been investigated. The present results show the high kinetic stability and low chemical reactivity of Tam and its important active metabolite, Endoxifen, in water medium. So a drug carrier with good aqueous solubility should be applied to improve the bioavailability of these antitumor drugs

The effect of solvents on formaldehyde adsorption performance on pristine and Pd doped on single-walled carbon nanotube using density functional theory

The electronic and structural properties of Pd doped single-walled carbon nanotubes show advantages as new nanocomposites that enable a wide variety of applications as nanosensors, nano storage devices, nanoplatform in biosensors. Our previous research demonstrated that Pd atom loaded onto single-walled carbon nanotubes have been shown that sensitivity of Pd/CNT toward CH2O in gas phase is twelve times opposed to intrinsic CNT. A detail and widespread study of solvent effects on adsorption of formaldehyde onto pristine single-walled carbon nanotube and Pd loaded on carbon nanotubewas performed under density functional theory framework. Based on the results, carbon nanotube showed no obvious sensitivity toward formaldehyde in considered solvents including water, methanol, ethanol, acetone and carbon tetrachloride. Electronic properties of Pd/CNT after CH2O adsorption were considerably changed. Also, the most and the least adsorption energywere reported in the presence of carbon tetrachloride and methanol from O (O-Pd/CNT) and para (para-Pd/CNT) orientations with −1.174 eV and −0.519 eV adsorption energy respectively. NBO analyses showed in the similar transfers, there was the most strong charge transfer from formaldehyde (O orientation) to Pd/CNT in carbon tetrachloride solution through lone pair of O atom toward lone pair* of Pd site with second-order perturbation energy (E(2)) equal 113.345 kJ/mol. These results are representative of strong chemisorption between CH2O and Pd/CNT in the presence of carbon tetrachloride. Quantum theory of atom in molecule (QTAIM) calculations indicate that the most accumulated electron charge densitywas between Pd-O in the O-Pd/CNT in carbon tetrachloride organic solution

Optimization of electrocoagulation process for efficient removal of ciprofloxacin antibiotic using iron electrode; kinetic and isothermstudies of adsorption

The present study focused on the removal of ciprofloxacin from hospital wastewater using electrocoagulation (EC) process by iron electrode and the kinetic and isotherms of adsorption were investigated. Response surface methodology (RSM) was used to evaluate the main effects of parameters, their simultaneous interactions and quadratic effect to achieve the optimum condition for EC process. The maximum removal rate was achieved at the current density of 15 mA·cm−2, initial CIP concentration of 60 mg·L−1, pH 7.5, inter-electrode distance 1.58 cm and electrolyte dose of 0.07 M NaCl within the equilibrium time of 20 min. The obtained experimental results are in good accordance with the Langmuir isotherm model for CIP adsorption on iron hydroxide by predicting themaximum adsorption capacity of 476.19 mg·g−1. The predictedmodel for treatment of synthetic wastewater is in satisfactory agreement with real hospital wastewater treatment. First and second order kinetic modelswere studied to figure out the exactmechanismof the CIP removal using EC process. The obtained results revealed that the second order kinetic model best fitted the experimental results and suggested that the chemisorptionmechanismcontrolled the adsorption of CIP. Under the optimal conditions of EC process, electrode consumption (ELC) and electrical energy consumption (EEC) were found to be 0.0625 g during a single run and 0.522 kWh·m−3, respectively

Fullerene-C60 and crown ether doped on C60 sensors for high sensitive detection of alkali and alkaline earth cations

Fullerenes are effective acceptor components with high electron affinity for charge transfer. The significant influences of chemical adsorption of the cations on the electrical sensitivity of pristine C60 and 15-(C2H4O)5/C60 nanocages could be the basis of new generation of electronic sensor design. The density functional theory calculation for alkali and alkaline earth cations detection by pristine C60 and 15-(C2H4O)5/C60 nanocages are considered at B3LYP level of theory with 6–31 G(d) basis set. The quantum theory of atoms in molecules analysis have been performed to understand the nature of intermolecular interactions between the cations and nanocages. Also, the natural bond orbital analysis have been performed to assess the intermolecular interactions in detail. Furthermore, the frontier molecular orbital, energy gap, work function, electronegativity, number of transferred electron (ΔN), dipole moment as well as the related chemical hardness and softness are investigated and calculated in this study. The results show that the adsorption of cations (M=Na+, K+, Mg2+ and Ca2+) are exothermic and the binding energy in pristine C60 nanocage and 15-(C2H4O)5/C60 increases with respect to the cations charge. The results also denote a decrease in the energy gap and an increase in the electrical conductivity upon the adsorption process. In order to validate the obtained results, the density of state calculations are employed and presented in the end as well

Palladium-Doped Single-Walled Carbon Nanotubes as a New Adsorbent for Detecting and Trapping Volatile Organic Compounds: A First Principle Study

Volatile organic compounds (VOCs) are in the vapor state in the atmosphere and are considered pollutants. Density functional theory (DFT) calculations with the wb97xd exchange correlation functional and the 6-311+G(d,p) basis set are carried out to explore the potential possibility of palladium-doped single-walled carbon nanotubes (Pd/SWCNT-V), serving as the resource for detecting and/or adsorbing acetonitrile (ACN), styrene (STY), and perchloroethylene (PCE) molecules as VOCs. The suggested adsorbent in this study is discussed with structural parameters, frontier molecular orbital theory, molecular electrical potential surfaces (MEPSs), natural bond orbital (NBO) analyses, and the density of states. Furthermore, following the Bader theory of atoms in molecules (AIM), the topological properties of the electron density contributions for intermolecular interactions are analyzed. The obtained results show efficient VOC loading via a strong chemisorption process with a mean adsorption energy of −0.94, −1.27, and −0.54 eV for ACN, STY, and PCE, respectively. Our results show that the Pd/SWCNT-V can be considered a good candidate for VOC removal from the environment

In silico evaluation of atazanavir as a potential HIV main protease inhibitor and its comparison with new designed analogs

Starting three decades ago and spreading rapidly around the world, acquired immunodeficiency syndrome (AIDS) is an infectious disease distinct from other contagious diseases by its unique ways of transmission. Over the past few decades, research into new drug compounds has been accompanied by extensive advances, and the design and manufacture of drugs that inhibit virus enzymes is one way to combat the AIDS virus. Since blocking enzyme activity can kill a pathogen or correct a metabolic imbalance, the design and use of enzyme inhibitors is a new approach against viruses. We carried out an in-depth analysis of the efficacy of atazanavir and its newly designed analogs as human immunodeficiency virus (HIV) protease inhibitors using molecular docking. The best designed analogs were then compared with atazanavir by the molecular dynamics simulation. The most prom ising results were ultimately found based on the docking analysis for HIV protease. Several exhibited an esti mated free binding energy lower than − 9.45 kcal/mol, indicating better prediction results than the atazanavir. ATV7 inhibitor with antiviral action may be more beneficial for infected patients with HIV. Molecular dynamics analysis and binding energy also showed that the ATV7 drug had more inhibitory ability than the atazanavir drug.Fil: Yoosefian, Mehdi. Graduate University of Advanced Technology; IránFil: Moghani, Maryam Zeraati. Graduate University of Advanced Technology; IránFil: Juan, Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; Argentin

Molecular dynamics simulations on interaction of ssDNA-causing DM1 with carbon and boron nitride nanotubes to inhibit the formation of CTG repeat secondary structures

Exposure of genomic, single-stranded DNA (ssDNA) during transcription and replication creates opportunities for the formation of inappropriate secondary structures. CTG repeat has been shown to form stable secondary structures that are the cause of inherited human genetic disease related to the myotonic dystrophy. Here, we investigated the role of SWCNT and BNNT in preventing CTG repeat using molecular dynamics (MD) simulations. The assessment of the simulations reveals that the ssDNA undergoes rapid conformational changes and wrap around the SWNTs via π-stacking interactions between SWNT’s wall and the nucleobases of the ssDNA. The ssDNA is observed to spontaneously wrap around SWNTs into compact right-handed helice within a few nanoseconds. Helical wrapping is driven by the electrostatic and torsional interactions within the sugar–phosphate backbone that result in ssDNA wrapping from the 3′end to the 5′end. Our computations demonstrate that the binding strength of the ssDNA to the SWCNT is substantially greater than to the BNNT. These findings would enable providing new avenues for therapeutic interventions in of myotonic dystrophy and potentially other triplet repeat disorders.Fil: Yoosefian, Mehdi. Graduate University Of Advanced Technology; IránFil: Mirhaji, Elnaz. Graduate University Of Advanced Technology; IránFil: Afshar, Mahboubeh. Graduate University Of Advanced Technology; IránFil: Juan, Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Física del Sur. Universidad Nacional del Sur. Departamento de Física. Instituto de Física del Sur; Argentin