Potent BACE1 inhibitors 4a,c,f, 5a–c showed moderate inhibition against two other enzymes implicated in AD pathogenesis, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), with IC50s ranging between 56.1 ~ 95.8 μM and 19.5 ~ 79.0 μM, respectively. Here, ACHE is linked to Alzheimer disease.