Faten M. Atlam

Molecular docking, molecular modeling, vibrational and biological studies of some new heterocyclic α-aminophosphonates

A new diphenyl (aryl) (Ǹ-quinazolin-4-yl-hydrazino) methylphosphonates 3a-3d was synthesized via anhydrous zinc chloride catalyzed Kabachnic-Fields reaction. The structure of the synthesized compounds was confirmed by elemental analysis, FT-IR, 1H NMR, 13C NMR, 31P NMR and MS spectral data. The synthesized compounds showed significant antimicrobial and also remarkable cytotoxicity anticancer activities against breast carcinoma cell line (MCF7). The quantum chemical calculations were performed using density functional theory (DFT) to study the effect of the changes of molecular and electronic structures on the biological activity of the investigated compounds. Also, NBO and theoretical FT-IR were calculated. The experimental results were validated by molecular docking simulation of compound 3b in the active pocket of the enzyme. The important binding interactions with the key residues in the active site were revealed. A good correlation was found between the quantum chemical parameters and experimental data.

Factors Influencing the Potency of Alzheimer Inhibitors: Computational and Docking Studies

Density functional theory (B3LYP/6-31G [d]) is performed to study the effect of molecular and electronic structures of the investigated β-secretase 1 (BACE1) Alzheimer’s inhibitors on their biological activities and discuss the correlation between their inhibition efficiencies and quantum chemical descriptors. IC50 values of the investigated compounds are mostly affected by the substituted R2 phenyl moiety. The calculations show that the presence of electron withdrawing group increases the half maximal inhibitory concentration (IC50). Structure–activity relationship studies show that the electronic descriptors, energy of high occupied molecular orbital, ΔE, lipophilicity, hardness, and ionization potential index, are the most significant descriptors for the correlation with IC50. Molecular docking simulation is performed to explain the mode of interaction between the most potent drug and the binding sites of the BACE1 target. A good correlation between the experimental and the theoretical data confirms that the quantum chemical methods are successful tools for the discovery of novel BACE1 drugs.

Diarylethylene guest anchored into a cyclodextrin molecular host: optical, quantum chemical studies and biological activity

Abstract The host–guest complexation between a novel guest namely; 2-(4-pyridinylbenzothiazolyl) ethane, PBE and β-cyclodextrin was studied using steady-state absorption and emission techniques. The fluorescence maximum is strongly blue-shifted with a great enhancement in the fluorescence intensity upon addition of β-CD, confirming the formation of inclusion complexes. The solid inclusion complex between PBE and β-CD has been prepared, characterised using FT-IR, X-ray diffraction and scanning electron microscope techniques. PBE is encapsulated with β-CD nanocavity and 1:1 PBE–β-CD host–guest interaction is identified. This is confirmed using semi-empirical quantum chemical calculations. PBE guest entered into the less polar cavity through the benzothiazole moiety. The negative values of enthalpy and free energy changes suggest that the encapsulation process is thermodynamically favourable. Additionally, the fluorescence is more sensitive to the micellar medium, whether it was cationic, anionic or neutral as well as metal ions like, Li+, Cu2+ and Fe3+. Finally, the antimicrobial activities of PBE guest and its inclusion complex with β-CD host are studied.