hMAO-B-IN-9 (Compound 25c) is a non-competitive inhibitor for monoamine oxidase B ( MAO-B ) with an IC 50 of 1.58 µM (hMAO-B). hMAO-B-IN-9 forms complex with iron ions as a chelator, and inhibits Erastin -induced ferroptosis. hMAO-B-IN-9 exhibits antioxidant activity by downregulating the level of reactive oxygen species ( ROS ). hMAO-B-IN-9 improves cognitive function in mice, without significant toxicity (30 mg/kg). hMAO-B-IN-9 is blood-brain barrier permeable, according to the in silico prediction.