Although the role of tertiary nitrogen in ring A and polycyclic structure is of great importance in drug-receptor affinity, in silico studies have emphasized the role of sidechains in C13, C14, C8, etc. Moreover, some of the DAs have potent acetylcholinesterase inhibitory activity, which indicates their potential against neurodegenerative disorders such as Alzheimer’s disease. This evidence concerns the gene ACHE and early-onset autosomal dominant Alzheimer disease.