Design and applications of bioprecursors: a retrometabolic approach

Bioprecursor by definition is a type of prodrug that is designed to tackle pharmaceutical, pharmacokinetic or pharmacodynamic shortcomings of a drug that limit its clinical use. A retrometabolic approach is used to design bioprecursors which upon activation by either phase-I or phase-II metabolic enzymes result into an active metabolite. A bioprecursor differs from its active metabolite in many respects like physico-chemical, biological and toxicological aspects. Present review focuses on salient features of design and chemistry of bioprecursors and their active metabolites, activating metabolic enzymes/reactions, reported examples from literature and applications. We hope that this extensive compilation would open doors to bioprecursors and their active metabolites as very promising resources for the discovery of novel drugs possessing high efficacy with lower number and extent of adverse effects.