LAUSR

A series of new bifunctional 7-benzyloxy-2, 3-dimethyl-4-oxo-4H-chromene-8-carboxamides 5a - 5 l were synthesized from 7-hydroxy 2,3 dimethyl chromone via key intermediate 7-benzyloxy 2,3 dimethyl-8-carboxylic acid using Jones oxidation and HBTU/HOBt (Hexafluorophosphate Benzotriazole Tetramethyl Uronium/Hydroxybenzotriazole) as selective amide coupling agent. All the amide derivatives 5a - 5 l were screened for their in vitro human monoamine oxidase, h MAO-A and h MAO-B inhibitory activity. Two compounds 5c and 5e , identified as more potent MAO-B inhibitors (IC 50 values within nanomolar range) compared to the standard MAO-B inhibitor, Selegiline. Five compounds 5b, 5c, 5e, 5 g and 5 k exhibited high MAO-B inhibition selectivity with selectivity index (SI) value > 50. The most potent compound 5e has also showed reversibility of MAO-B inhibition in dialysis method with relative recovery percentage up to 69.9%. Furthermore, the MAO-B selective binding affinities of these newly synthesized chromone amides and structure activity relationships were scrutinized with the help of quantified scoring function values from Genetic Optimization of Ligand Docking (GOLD). The docking results have conclusively lain out that these chromone carboxamides show positive interactions with h MAO-B and repulsive interactions with h MAO-A which affirm its selectivity towards MAO-B. Graphic abstract