Search

A detailed multistep framework combining quantitative structure-activity relationship, global reactivity, absorption, distribution, metabolism and elimination properties, molecular docking and molecular dynamics simulation (MD) on a series of Selective Estrogen Receptor Down-Regulators (SERDs) interacting with Estrogen Receptor α (ERα) has been performed. The partial least squares regression method derived an empirical model with better predictive capability. The results of global reactivity descriptors revealed that all the compounds are considered strong electrophiles, allowing them to participate in polar reactions more easily. The Brain Or IntestinaL EstimateD permeation diagram revealed that compounds 49 and 31 were predicted to be well absorbed by the human gastrointestinal tract and would not enter the brain. The elucidation of the binding mode between the most active compounds that comply with Lipinski’s and Veber’s rules from the dataset and ERα targets was explored by molecular docking. The MD simulations were performed for 100 ns on the best compounds, which indicated their stability state under dynamics simulations. These findings are expected to help predict the anticancer activities of the studied SERD compounds and better understand their binding mechanism with ERα targets. Communicated by Ramaswamy H. Sarma

International audience; The equilibrium geometries of 1,3,4-thiadiazole derivatives have been determined and analyzed at DFT level employing B3LYP/6-31G(d) basis set. 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).Results such us, fundamental vibrational modes, 1H NMR isotropic chemical shifts, frontier orbital energies (HOMO, LUMO), band gap energy, dipole moments, net charges are reported and discussed in terms of reactivity of 1,3,4-thiadiazole derivatives. The HOMO and LUMO analysis were used to elucidate information regarding charge transfer within the molecule. Isotropic chemical shifts were calculated using the Gauge-Independent Atomic Orbital (GIOAO) method. Finally, a comparison between the experimental data and the calculated results appeared a good agreement and show exceptional reactivity. © 2019 Editura Academiei Romane. All rights reserved.

The recent new contagion coronavirus 2019 (COVID-19) disease is a new generation of severe acute respiratory syndrome coronavirus-2 SARS-CoV-2 which infected millions confirmed cases and hundreds of thousands death cases around the world so far. Molecular docking combined with molecular dynamics is one of the most important tools of drug discovery and drug design, which it used to examine the type of binding between the ligand and its protein enzyme. Global reactivity has important properties, which enable chemists to understand the chemical reactivity and kinetic stability of compounds. In this study, molecular docking and reactivity were applied for eighteen drugs, which are similar in structure to chloroquine and hydroxychloroquine, the potential inhibitors to angiotensin-converting enzyme (ACE2). Those drugs were selected from DrugBank. The reactivity, molecular docking and molecular dynamics were performed for two receptors ACE2 and [SARS-CoV-2/ACE2] complex receptor in two active sites to find a ligand, which may inhibit COVID-19. The results obtained from this study showed that Ramipril, Delapril and Lisinopril could bind with ACE2 receptor and [SARS-CoV-2/ACE2] complex better than chloroquine and hydroxychloroquine. This new understanding should help to improve predictions of the impact of such alternatives on COVID-19. Communicated by Ramaswamy H. Sarma

Recently, a series of carbazole derivatives containing chalcone analogues (CDCAs) were synthetized as potent anticancer agents and apoptosis inducers. These compounds target the inhibition of topoisomerase II and present cytotoxic activities. After comparison to experiment, we validated the use of B3LYP, a density functional theory-based approach, to describe the structure and molecular properties of the carbazole subunit and CDCAs compounds of interest. Then, we derived relationships between the chemical descriptors and activity of these carbazole derivatives using multi-parameter optimization and quantitative structure activity relationships (QSAR) approaches. For the QSAR studies, we used multiple linear regression and artificial neural network statistical modelling. Our predicted activities are in good agreement with the experimental ones. We found that the most important parameter influencing the activity of the considered compounds is the octanol-water partition coefficient, highlighting the importance of flexibility as a key molecular parameter to favor cell membrane crossing and enhance the action of these CDCAs against topoisomerase II. Our results provide useful guidelines for designing new oral active CDCAs medicaments for cytotoxic inhibition.

To establish a quantitative structure-activity relationship, 54 indazole derivatives were analyzed by multiple linear regression MLR. The DFT-B3LYP method, with the basis set 6-311G, was performed to define the structure, chemical reactivity and properties of the compounds. This study was accompanied by molecular docking, global reactivity descriptors, absorption, distribution, metabolism and elimination (ADME) properties on a series of 21 compounds of selective estrogen receptor degraders (SERDs) that present the most active compounds from the dataset. The MLR regression equation displayed a good agreement between fitted and observed biological activities. A high average R2Boots greater than 0.5 indicates that the obtained model has good predictive power and robustness. In addition, an average value of R2pred (0.57) approximately equal to 0.6 may be taken as an indicator of good external predictability. The interactions between the most active compounds from the indazole series and ERα targets were explored through a molecular docking to elucidate the binding mode between the studied compounds and corresponding protein. Based on this study compounds 14, 43, 8 and 45 have no violated Lipinski’s rule of five and Veber’s rule, suggesting that these compounds would not have problems with oral bioavailability. Most of global reactivity results have an agreement with those obtained in this docking study.

Conformational analysis of 18-ring membered macrolactones has been carried out using molecular mechanics calculations and molecular dynamics. A high conformational flexibility of macrolactones was obtained, and an important stereoselectivity was observed for the complexed macrolides. For 18d macrolactone, which was presented by a most favored conformer with 20.1% without complex, it was populated with 50.1% in presence of Fe(CO)3.