Drug design, synthesis, in vitro and in silico evaluation of selective monoaminoxidase B inhibitors based on 3-acetyl-2-dichlorophenyl-5-aryl-2,3-dihydro-1,3,4-oxadiazole chemical scaffold.

With the aim to identify new, potent and selective monoamine oxidase B (MAO-B) inhibitors, molecular interaction field analysis has been applied to a MAO-B complex with 3-acetyl-2,5-diaryl-2,3-dihydro-1,3,4-oxadiazole chemical structure, known as a privileged scaffold for this target. Several compounds displayed potent in vitro activity, exhibiting IC50 values in the medium to low nanomolar range. The enantiomers of most promising derivatives were separated by enantioselective HPLC and in vitro evaluated. Experimental results, according to theoretical drug design, clearly indicated a key role of the ligand stereochemistry in the target recognition/inhibition. In particular the (R)- enantiomers showed the best activity with respect to the (S)- stereoisomer. Finally, docking experiments coupled to molecular dynamics (MD) simulations, were applied for understanding the putative MAO -B binding modes of the new compounds providing detailed information for further structural optimization.