AD is the most common type of dementia, characterized by advancing memory 
deterioration that ultimately leads to the complete loss of intellectual and mental 
abilities leading to loss of the ability to carry on a conversation and respond to the 
environment. It can seriously affect a person's ability to carry out daily activities. 
The morphological and biochemical characteristics of AD are central to modern 
strategies for developing new medical approaches. Amyloid plaques, which are 
primarily made of Ab, progressively form in the brains of AD patients, and 
mutations in three genes (APP, PS1, and PS2) cause FAD by increasing the 
synthesis of the toxic Ab42 peptide. Given the strong link between Ab and AD, 
therapeutic strategies that lower Ab concentrations in the brain should be useful in 
the treatment of AD. For over the past years, the molecular identities of these 
proteases remained unknown. ß-secretase has been identified as the novel 
transmembrane aspartic protease, ß-site APP Cleaving Enzyme 1 (BACE1, also 
known as Asp2 and memapsin 2). BACE2, a novel protease similar to BACE1, was 
also discovered, and the two BACE enzymes form a new family of transmembrane 
aspartic proteases. BACE1 has all of the properties of a ß-secretase, and as the key 
enzyme that initiates the formation of Ab, it is a promising drug target for AD. This 
review summarizes AD treatment from a medicinal chemistry perspective, as well 
as the development of novel AD remedies (BACE inhibitors).