Inhibitory Effects of Novel 7-Substituted 6-iodo-3-<i>O</i>-Flavonol Glycosides against Cholinesterases and β-secretase Activities, and Evaluation for Potential Antioxidant Properties

A series of 7-halogeno- (X = F, Cl, Br) and 7-methoxy-substituted acetylated 6-iodo-3-<i>O</i>-flavonol glycosides were prepared, and evaluated for inhibitory effect in vitro against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. 7-Bromo-2-(4-chlorophenyl)-6-iod...

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Bibliographic Details
Main Authors: Emmanuel N. Agbo, Samantha Gildenhuys, Malose J. Mphahlele
Format: Article
Language:English
Published: MDPI AG 2019-09-01
Series:Molecules
Subjects:
Online Access:https://www.mdpi.com/1420-3049/24/19/3500
Description
Summary:A series of 7-halogeno- (X = F, Cl, Br) and 7-methoxy-substituted acetylated 6-iodo-3-<i>O</i>-flavonol glycosides were prepared, and evaluated for inhibitory effect in vitro against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) activities. 7-Bromo-2-(4-chlorophenyl)-6-iodo-4<i>H</i>-chromen-4-one-3-<i>O</i>-2,3,4,6<i>-O</i>-tetraacetyl-&#946;-<i>d</i>-glucopyranoside (<b>2k</b>) and 7-bromo-6-iodo-2-(4-methoxyphenyl)-4<i>H</i>-chromen-4-one-3-<i>O</i>-2,3,4,6-<i>O</i>-tetraacetyl-&#946;-<i>d</i>-glucopyranoside (<b>2l</b>) exhibited significant inhibitory effect against AChE activity when compared to the activity of the reference standard, donepezil. Compound <b>2k</b> was found to be selective against AChE and to exhibit reduced inhibitory effect against BChE activity. 6-Iodo-7-methoxy-2-(4-methoxyphenyl)-4<i>H</i>-chromen-4-one-3-<i>O</i>-2,3,4,6-<i>O</i>-tetraacetyl-&#946;-<i>d</i>-glucopyranoside (<b>2p</b>) was found to exhibit increased activity against BChE, more so than the activity of donepezil. The most active compounds were also evaluated for inhibitory effect against &#946;-secretase activity and for potential radical scavenging activities. The experimental data were complemented with molecular docking (in silico) studies of the most active compounds into the active sites of these enzymes.
ISSN:1420-3049