A cell-permeable, relatively non-toxic, 1,8-naphthyridine derived compound that blocks the inhibitory effect of protein phosphatase inhibitors, such as okadaic acid, on protein phosphatase 2A (PP2A). Exhibits blood-brain barrier permeability. Protects neurons against beta-amyloid peptides (Ab1-42) toxicity and okadaic acid-induced tau hyperphosphorylation. Also protects against rotenone and oligomycin A induced neurotoxicity in SH-SY5Y neuroblastoma cells (at ~300nM). Prevents the development of glutamate-induced neuronal lesions in rat hippocampal slices by up-regulating PP2A (~3uM). Shown to reverse the scopolamine-induced memory loss in mice (~10mg/kg i.p) and significantly reduces the infarct volume in an animal model of stroke (~2.5mg/kg). Also acts as an inhibitor of acetylcholinesterase activity in Electrophorus electricus (IC50 = 60nM) and human erythrocytes (IC50 = 780nM).