Alignment-independent 3D-QSAR and molecular docking studies of tacrine-4-oxo-4H-Chromene hybrids as anti-Alzheimer's agents.

A series of novel tacrine derivatives as multifunctional agents with potential inhibitory effects on both acetylcholinesterase(AChE) and butyrylcholinesterase (BuChE) enzymes for the treatment of Alzheimer's disease(AD), were applied to alignment independent 3D-QSAR methods using Pentacle software. In this studies, GRID-independent molecular descriptors (GRIND) analysis have been applied to characterize important interactions between enzymes and the studied compounds. Two H-bond acceptor groups as well as hydrophobic properties of tacrine rings for AChE and two H-bond acceptor on the carbonyl group of chromene and NH of amid group for BuChE, with positive effects on their inhibitory potency have been identified. The obtained 3D-QSAR models have been analyzed and validated. The statistical quality of the QSAR model for AChE, r = 0.87, q = 0.56 and for BuChE, r = 0.96, q = 0.70 was resulted. Using these models, novel structures have been designed and pIC of them were predicted. Molecular docking studies were also conducted on AChE (1ACJ) and BuChE (4BDS) and promising results in good agreement with 3D-QSAR studies were obtained.