Thermodynamic, Structural and Transport Properties of Lennard-Jones Liquid Systems. A Molecular Dynamics Simulations of Liquid Helium, Neon, Methane and Nitrogen

Molecular dynamics calculations are carried out in order to find the properties of Lennard Jones liquids in different state points of their phase diagram. The spherical shape and the stability of the helium, neon, methane and nitrogen make the liquids easily accessible to numerical simulation. Thermodynamic, structural, and transport properties are studied and compared with both experimental data and recent theoretical investigations. In the present work, up to 22 state points are covered, some of which are near or at the triple point. It will be shown that the classical approach leads to data that are in very good agreement with experiments and other types of calculations. At high temperatures and low densities, we observe a decrease in the uncertainties in the stress autocorrelation function by increasing the number of iterations

Drug likeness scoring and quantitative structure anaplastic lymphoma kinase (ALK) inhibitors activities relationships of pyrazolone derivatives

Series of twenty-four compounds was the field for applying multi-parameter optimization (MPO) methods and qualitative approximations of structural activity relationships in order to determine the role of various physico-chemical and quantum descriptors used in QSAR modeling as independent variables. Anaplastic lymphoma kinase (ALK) inhibitory activity was considered as a component in this study. In order to illustrate the quantitative relationships between the molecular descriptors and the activity of pyrazolone derivatives, we have applied a multiple linear regression (MLR) procedure. By adopting cross-validation with the leave-one-out method, we could estimate the predictability of models. Our results suggest a QSAR model based on the following descriptors: S, V, LogP, POL, Ref, HOMO, LUMO, E, , HBA, PSA and NRB, for the inhibitory activities against ALK. Results show high correlation between experimental and predicted activity values, indicating the validation and the good quality of the QSAR model. Copyright © 2018 American Scientific Publishers All rights reserved

Qualitative and quantitative structure-activity relationships studies of quercetin derivatives as chemotherapeutic activity

Qualitative and Quantitative structure activity relationship (SAR/QSAR) analysis was applied to eighteen Quercetin derivatives using a combination of various physicochemical, steric, electronic, and structural molecular descriptors. A multiple linear regression (MLR) procedure was used to model the relationships between molecular descriptors and the chemotherapeutic activity of the Quercetin derivatives. The stepwise regression method was used to derive the most significant models as a calibration model for predicting the inhibitory activity of this class of molecules. The best QSAR models were further validated by a leave one out technique as well as by the calculation of statistical parameters for the established theoretical models. High agreement between experimental and predicted inhibitory values, obtained in the validation procedure, indicated the good quality of the derived QSAR models. Copyright © 2018 American Scientific Publishers All rights reserve

Structural investigation, drug likeness scoring and structure activity/property relationships applied on 1,2,3-thiadiazole derivatives, with kinase inhibitors activity

All calculations and the equilibrium geometries of 1,2,3-thiadiazole have been performed using ab initio/HF, MP2 and DFT methods with different basis sets. The molecular electrostatic potential surface (MESP) that reveals centers of reactivity of the molecule and substitution effects of the molecular system have been studied using the HSAB principle (Hard Soft Acid and Base). Also, the multi-parameter optimization (MPO) methods and structure activity/property relationship studies were carried out on twenty-one molecules of 1,2,3-thiadiazole derivatives which are potent VEGFR-2/KDR kinase inhibitors. In the present work results such as net charges, bond lengths, dipole moments, QSAR properties, Lipinski’s parameters, Lipophilic Efficiency (LipE), have been calculated and discussed. (Figure Presented). © 2017, Editura Academiei Romane. All rights reserved

Computational study of molecular electrostatic potential, drug likeness screening and structure-activity/property relationships of thiazolidine-2,4-dione derivatives

International audienceMolecular geometry, electronic properties, effect of the substitution, and structure physical-chemistry relationship for thiazolidine-2,4-dione derivatives have been studied by density functional theory (DFT) theory. In the present work, the calculated values, namely, net charges, molecular electrostatic potential (MESP) contours/surfaces have also been drawn to explain the electronic activity of thiazolidine-2,4-dione, bond lengths, dipole moments, heats of formation, Quantitative structure- activity relationship (QSAR) properties, Lipinski's and Veber's parameters, Ligand efficiency (LE), Lipophilic Efficiency (LipE), etc., are reported and discussed in this paper. Copyright © 2016 American Scientific Publishers

Quantitative structure anti-proliferative activity against HEPG2 and SW1116 relationships in a series of Pyrazine Derivatives

International audienceQuantitative structure activity relationship (QSAR) methods have been applied in several scientific studies including chemistry, biology and toxicology and drug discovery to predict and classify biological activities of virtual or newly-synthesized compounds. QSAR models can also be used in designing new chemical entities and are now regarded as essential tools in pharmaceutical industries to identify promising hits and generate high quality leads in the early stages of drug discovery. QSAR studies were performed on a series of pyrazine as anti-proliferative agents. A multiple linear regression (MLR) procedure was used to envisage the relationships between molecular descriptors and the activity of pyrazine derivatives. The predictivity of the model was estimated by cross-validation with the leave-one-out method. Our results suggest a QSAR model based of the following descriptors: logP, HE, SAG, Pol, qC3 for the anti-proliferative activity against the HEPG2 (human liver cancer cell) and logP, HE, MR, SAG, Vol, qC2, qC5, qC6, LUMO for the anti-proliferative activity against the SW1116 (human colorectal carcinoma cell). To confirm the predictive power of the models, an external set of molecules was used. High correlation between experimental and predicted activity values was observed, indicating the validation and the good quality of the derived QSAR models. Copyright © 2017 American Scientific Publishers All rights reserved

QSAR studies of 1,2,5-thiadiazole derivatives analogues of aceclidine as potent M1 muscarinic agonists

International audienceIn the present study, Quantitative structure-activity relationship (QSAR) study have been performed on twenty molecules of 1,2,5-thiadiazole derivatives. The compounds studied are the analogues of aceclidine as potent M1 muscarinic agonists. A multiple linear regression (MLR) procedure was used to design the relationships between molecular descriptors and biological activity of the 1,2,5- thiadiazole derivatives. The predictivity of the model was estimated by cross-validation with the leave-one-outmethod. Our results suggest a QSAR model based on the following descriptors Log P , HE, Pol, MR, MV, and MW, SAG, and Etotal. High correlation between experimental and predicted activity values was observed, indicating the validation and the good quality of the established QSAR models. © 2018 American Scientific Publishers

A multifunctional organometallic switch with carbon-rich ruthenium and diarylethene units

International audienc