In addition, it was confirmed that the ‘Qi-Nan’ leaves flavonoids possessed a powerful antioxidant capacity, acetylcholinesterase-inhibiting activity, and α-glucosidase-inhibiting activity, which have the potential to be developed into natural antioxidants, hypoglycemic drugs, and Alzheimer’s disease-preventive drugs. Here, ACHE is linked to early-onset autosomal dominant Alzheimer disease.