Design of vilazodone-donepezil chimeric derivatives as acetylcholinesterase inhibitors by QSAR, molecular docking and molecular dynamics simulations.

Alzheimer's disease (AD) is a disease that affects the cognitive abilities of older adults, and it is one of the biggest global medical challenges of the 21st century. Acetylcholinesterase (AChE) can increase acetylcholine concentrations and improve cognitive function in patients, and is a potential target to develop small molecule inhibitors for the treatment of Alzheimer's disease (AD). In this study, 29 vilazodone-donepezil chimeric derivatives are systematically studied using 3D-QSAR modeling, and a robust and reliable Topomer CoMFA model was obtained with: q2 = 0.720, r2 = 0.991, F = 287.234, N = 6, and SEE = 0.098. Based on the established model and combined with the ZINC20 database, 33 new compounds with ideal inhibitory activity are successfully designed. Molecular docking and ADMET property prediction also show that these newly designed compounds have a good binding ability to the target protein and can meet the medicinal conditions. Subsequently, four new compounds with good comprehensive ability are selected for molecular dynamics simulation, and the simulation results confirm that the newly designed compounds have a certain degree of reliability and stability. This study provides guidance for vilazodone-donepezil chimeric derivatives as a potential AChE inhibitor and has certain theoretical value.

The novel therapeutic strategy of vilazodone-donepezil chimeras as potent triple-target ligands for the potential treatment of Alzheimer's disease with comorbid depression.

Depression is one of the most frequent comorbid psychiatric symptoms of Alzheimer's disease (AD), and no efficacious drugs have been approved specifically for this purpose thus far. Herein, we proposed a novel therapeutic strategy that merged the key pharmacophores of the antidepressant vilazodone (5-HT1A receptor partial agonist and serotonin transporter inhibitor) and the anti-AD drug donepezil (acetylcholinesterase inhibitor) together to develop a series of multi-target-directed ligands for potential therapy of the comorbidity of AD and depression. Accordingly, 55 vilazodone-donepezil chimeric derivatives were designed and synthesized, and their triple-target activities against acetylcholinesterase, 5-HT1A receptor, and serotonin transporter were systematically evaluated. Among them, compound 5 displayed strong triple-target bioactivities in vitro, low hERG potassium channel inhibition and acceptable brain distribution. Importantly, oral intake of 5 mg/kg of the compound 5 dihydrochloride significantly alleviated the depressive symptoms and ameliorated cognitive dysfunction in mouse models. In brief, these results highlight vilazodone-donepezil chimeras as a prospective therapeutic approach for the treatment of the comorbidity of AD and depression.

The binding mode of vilazodone in the human serotonin transporter elucidated by ligand docking and molecular dynamics simulations.

Vilazodone is a novel antidepressant used for the treatment of major depressive disorder (MDD) with a primary action mechanism of inhibiting the human serotonin reuptake transporter (hSERT) and acting as a 5-HT1A receptor partial agonist. The interaction between vilazodone and the 5-HT1A receptor has been reported, however, the binding mode of vilazodone in the hSERT remains elusive. In the current study, to elucidate the molecular mechanism of vilazodone binding in the hSERT, the drug and its five analogs were docked into the hSERT crystal structure as initial conformations and were sampled by 400 ns molecular dynamics (MD) simulations. Through the analysis of the profiles of protein-ligand binding free energies, interaction fingerprints, and conformational rearrangements, the binding mode of vilazodone in the hSERT was revealed. As a result, unlike the classical antidepressants located in the S1 site of the hSERT, vilazodone adopted a linear pose in the binding pocket. Its arylpiperazine fragment occupies the central site (S1) and interacts with Y95, D98, I172, Y176, F335, F341, S438, and T439, while the indole fragment extends to the allosteric site (S2) via interacting with the ionic switch (R104/E403) between the two sites. The new insights obtained are not only helpful in understanding the binding mode of vilazodone in the hSERT, but also provide valuable guidance to the discovery of novel antidepressant drugs.

Design, synthesis and evaluation of vilazodone-tacrine hybrids as multitarget-directed ligands against depression with cognitive impairment.

Depression, a severe mental disease, is greatly difficult to treat and easy to induce other neuropsychiatric symptoms, the most frequent one is cognitive impairment. In this study, a series of novel vilazodone-tacrine hybrids were designed, synthesized and evaluated as multitarget agents against depression with cognitive impairment. Most compounds exhibited good multitarget activities and appropriate blood-brain barrier permeability. Specifically, compounds 1d and 2a exhibited excellent 5-HT1A agonist activities (1d, EC50 = 0.36 ±â€¯0.08 nM; 2a, EC50 = 0.58 ±â€¯0.14 nM) and 5-HT reuptake inhibitory activities (1d, IC50 = 20.42 ±â€¯6.60 nM; 2a, IC50 = 22.10 ±â€¯5.80 nM). In addition, they showed moderate ChE inhibitory activities (1d, AChE IC50 = 1.72 ±â€¯0.217 µM, BuChE IC50 = 0.34 ±â€¯0.03 µM; 2a, AChE IC50 = 2.36 ±â€¯0.34 µM, BuChE IC50 = 0.10 ±â€¯0.01 µM). Good multitarget activities with goodt blood-brain barrier permeability of 1d and 2a make them good lead compounds for the further study of depression with cognitive impairment.

Development and Validation of a Stability-Indicating Liquid Chromatographic Method for Estimating Vilazodone Hydrochloride in Pharmaceutical Dosage Form Using Quality by Design.

A stability-indicating liquid chromatographic method was developed employing the principles of quality by design (QbD) to quantify vilazodone hydrochloride (VLN) in pharmaceutical dosage form. A Box-Behnken experimental design was employed to establish optimum conditions including method robustness by selecting organic phase proportion (%), mobile phase flow rate (mL/min) and pH of buffer as the factors, to study their effect on plate number as the response variable. Chromatography was performed on a C-18 column using methanol:phosphate buffer of pH 7.0 (85:15, v/v) as the mobile phase at a flow rate of 1.2 mL/min with photo diode array (PDA) detection at 285 nm. Calibration curve was linear over 5-80 µg/mL with values of accuracy within 99.4-100.8%. The limit of detection and quantification were found to be 1.5 and 5.0 µg/mL, respectively. The developed method revealed high specificity for VLN and its degradation products formed during forced degradation conditions. Furthermore, control strategies were developed based on system suitability test result. The QbD-based developed liquid chromatographic method was found suitable for routine analysis of VLN in bulk drug and pharmaceutical dosage form.