Combined Experimental and Computational Investigations of 4-Amino-2-Chloro-6,7-Dimethoxyquinazoline as Potential Anti-Alzheimer Agent

Abstract

Alzheimer's disease (AD) is a neurodegenerative condition that leads to the deterioration of brain cells, resulting in memory loss, thinking, and executive skills. In this work, 4-amino-2-chloro-6,7-dimethoxyquinazoline (ACDQ) has been studied using the 6–311++G(d,p) B3LYP functional of the density functional theory (DFT) approach utilizing a basis set. Geometry optimization and fundamental vibrational frequencies are calculated using the above method. The spectroscopic investigations such as FT-IR, FT-Raman, and UV–Vis spectra are performed on the selected compound. The time-dependent DFT calculations are performed in the gas and water phases to determine electronic properties and energy gap using the same basis set. Charge density distributions have been used to illustrate the energy gap between the highest occupied and lowest unoccupied molecular orbitals. Mulliken population analysis is performed to determine the atomic charges of ACDQ. From the natural bond orbital analysis, it is observed that there is a significant electron delocalization in ACDQ due to the presence of intramolecular interactions. To evaluate ACDQ's anti-Alzheimer potential, a molecular docking simulation is used to assess its structural stability and biological activity against proteins associated with Alzheimer's disease. Our docking study revealed that, ACDQ has a strong interaction with 4EY7 protein with binding energy of −8.1 kcal mol⁻¹. Additionally, metrics such as the root mean square deviation (RMSD), root mean square fluctuation (RMSF), and the radius of gyration are considered (R_g) were computed using molecular dynamics simulations to evaluate the stability of the protein–ligand interaction. Studies on the ADMET prediction of ACDQ have also been carried out. The findings of the current study support the potential of ACDQ as an effective lead therapeutic for Alzheimer's disease.