Potent inhibitions of monoamine oxidase A and B by acacetin and its 7-O-(6-O-malonylglucoside) derivative from Agastache rugosa

•Acacetin and its 7-O-(6-O-malonylglucoside) derivative (AMG) were potent for human MAO-A and MAO-B.•The introduction of a malonyl group at sugar moiety significantly increased inhibitory activity.•AMG reversibly and competitively inhibited MAO-A and MAO-B (Ki=1.06 and 0.38μM, respectively).•Acacetin and AMG were predicted to bind to Cys172 and Ile477 residues of MAO-B, respectively.•Acacetin and AMG can be viewed as new potent reversible MAO inhibitors or lead compounds.