In-silico investigations of novel tacrine derivatives potency against Alzheimer's disease

Abstract

Tacrine was originally used as a palliative treatment for Alzheimer's disease (AD). But early applications soon revealed a number of its side effects on human health. That's why we decided to examine the effectiveness of novel tacrine derivatives known for their potent inhibition of GluN2B-NMDA receptors, to discover the leading candidates for treating AD in terms of safety and molecular stability towards NMDA receptors. As a result, CoMFA and CoMSIA models were generated using 3-dimensional quantitative structure-activity relationships (3D-QSARs) study, indicating that Electrostatic, Hydrophobic, and Steric fields have a vital function in the NMDAR-antagonizing activities. The predictive exactitude of the generated CoMFA model (Q2cv = 0.699, R2 training = 0.980, R2 test = 0.737) and the top model of CoMSIA (Q2cv = 0.646, R2 training = 0.867, R2 test = 0.761) has been successfully tested in both internal and external validations. The pharmacokinetics properties of in-silico ADME-Toxicity confirm the safety of C24 and C27 compounds, which were discovered to be free from any skin allergy toxicity and hepatotoxic effects, and would be able to passively break through the blood-brain barrier and ultimately penetrate the central nervous system with a very good level of absorption (HIA exceeding 95%). The molecular docking results indicate that non-toxic inhibitors interact specifically with Gln110, Ser132, and Tyr109 amino acid residues as the main active sites of the transport protein encoded as 5EWJ.pdb. At last, the intermolecular mechanisms detected by the examined ligands labeled C24, and C27, revealed excellent levels of molecular stability towards the targeted protein along one hundred nano-seconds of molecular dynamics time. Therefore, C24 and C27 chemical compounds are strongly recommended to treat AD, due to their considerable similarity to drug candidates and high levels of molecular stability.