An Insight into Medicinal Chemistry and SAR Studies of Cholinesterase and BACE-1 Inhibitors for Alzheimer's Disease

Alzheimer's Disease (AD) is a serious neurodegenerative condition that predominantly impacts the cholinergic neurons of the entorhinal cortex and hippocampal regions, playing a critical role in learning, navigation, and brain processing. This paper aims to discuss the three main hypotheses of Alzheimer's disease, focusing on neurotoxicity and neurodegeneration caused by mitochondrial dysfunction and ROS production, particularly analyzing the susceptibility differences between genders. Our comprehensive review focuses on significant findings from the past five years, particularly on Cholinesterase (ChE) and BACE-1 inhibitors. Researchers have conducted a detailed analysis of in vitro, in silico, and in vivo data, incorporating extensive Structure-Activity Relationship (SAR) studies. The reviewed papers have been sourced from platforms, such as Google Scholar, Semantic Scholar, and ClinicalTrials.gov, and have been selected based on their AChE and BACE-1 inhibitory activity and structural motif similarity. The review identifies the most effective compounds targeting ChE and BACE-1, highlighting acridine, dihydropyridine, and thiazole-coumarin hybrids for ChE inhibition, and oxadiazole, benzofuran, and dihydropyrimidinone for BACE-1 inhibition. This demonstrates a diverse array of potent heterocyclic hybrids. The review presents a varied compilation of scaffolds showing promise in treating Alzheimer's disease, highlighting the potential of specific compounds against ChE and BACE-1. Given the critical insights derived from our analysis, we posit that this compilation will substantially contribute to the ongoing efforts to combat neurodegeneration and prolong dementia, underscoring the importance of continuous research in this domain.