A decennary update on diverse heterocycles and their intermediates as privileged scaffolds for cathepsin B inhibition

The identification of x-ray crystal structure of cathepsin B (CTSB) in the early 90's enabled researchers to embark on a journey to understand and demystify its multiple catalytic mechanisms (endopeptidase/carboxypeptidase/peptidyl-dipeptidase) in diverse physiological processes and their switching into one another under different conditions. The engagement of CTSB in different pathological conditions due to its over-expression further highlighted the enhanced research interest around the domain. The occurrence of over-expressed CTSB in various diseases like Alzheimer's, cancer, arthritis, cardiovascular, etc., and the use of CTSB inhibitors for the treatment of these diseases have established its involvement in different pathological conditions. Such an understanding tempted researchers to design, synthesize, and screen diverse classes of compounds against CTSB. This in turn, helped in understanding their interactions with the active sites of the enzyme. Heterocyclic compounds comprise a very rich and broad class of medicinally important compounds that also hold great potential for CTSB inhibition. This review covers the CTSB inhibition potential of various natural and synthetic heterocyclic scaffolds. Researchers working in the fields of molecular modeling, drug design and development, and enzyme inhibitors can benefit significantly from this review.