Molecular docking study of anthocyanidins and anthocyanins as acetylcholinesterase inhibitors

Abstract

Anthocyanidins and anthocyanins are flavonoid derivatives as known as plant derived color pigments in many red, purple and blue fruits and vegetables. Anthocyanins are in the form of glycosides, while anthocyanidins are aglycones. Many experiments indicated various health-benefits of these phytochemicals, especially neuroprotective effect via acetylcholinesterase (AChE) inhibition. To understand the binding interactions of some anthocyanidins and anthocyanins to the active site of AChE and to predict in silico inhibitory activity, molecular docking study was performed using AutoDock 4.2. Docking results showed that pelargonidin-3-glucoside exhibited the best docking profile in terms of good binding affinity and inhibitory activity against human AChE. The binding mode of pelargonidin-3- glucoside was comparable to donepezil, but different to other anthocyanins. The presence of glucose moiety in pelargonidin-3-glucoside structure seemed to play a crucial role for an additional binding interaction nearby the catalytic site (CS) of enzyme, however, enzyme-labile and high polar properties of this functionality may diminish the ability of the compound as a potential inhibitor against AChE.