Promising heterocycle-based scaffolds in recent (2019–2021) anti-Alzheimer's drug design and discovery

Alzheimer's disease (AD) is one of the neurodegenerative diseases that led to morbidity and mortality world-wide. It is a complex disease whose etiology is not completely known that leads to difficulty in prevention or cure of the AD. Also, there are only few approved drugs for AD treatment. Apart from deaths due to AD, expenditure of treatment and care of AD patients is higher than that of treatment of HIV and cancer diseases combined. Hence, it leads to an economic burden also. Although research is being carried out on designing drugs for AD, most of them have ended up in poor inhibitors with high toxicity. Hence, researchers should shoulder a great responsibility of discovery of efficient drugs for AD treatment. In the field of drug discovery, heterocycles played an important role. Also, most of the heterocyclic scaffolds have been used in design of potent anti-AD agents. In view of this, heterocyclic molecules reported recently are compiled and evaluated comprehensively. Especially, the molecules which exhibited pronounced activity are emphasized and described with respect to structure-activity relationship (SAR) in brief. [Display omitted] -4-Arylcoumarins and pyrazolo-pyridines showed the most promising anti-AChE activity.-Clorgyline-rasagiline hybrids and pyrrolo-pyridine analogs bestowed elite anti-MAOs activity.-Excellent GSK-3β/NO dual inhibitory was noticed for pyridine-oxadiazoles.-Chalcone O-alkylamines analogs rendered potent Aβ1-42 aggregation inhibitory activity.-Remarkable anti-PDE4B activity has been exhibited by quinoline and dihydroisoquinoline scaffolds.