title: When analoging is not enough: scaffold discovery in medicinal chemistry.
abstract: BACKGROUND
  As an integral part of lead generation and optimization, scaffold discovery has broad implications in drug discovery. Currently available chemical scaffolds might be inadequate to provide drug-like ligands for new targets such as phosphatases and protein-protein interactions and therapeutically useful chemical space needs to be continuously explored. New scaffolds are often desired to overcome major hurdles (e.g., potency plateau, selectivity, pharmacokinetics, etc.) in lead generation and optimization. Timely discovery of proof-of-concept compounds facilitates target validation, diversifies clinical candidates and improves the overall success rate of drug discovery.
  
  
  METHODS
  This analysis discusses the strategies involved in finding new scaffolds (i.e., fragment-, ligand- and structure-based design) and their applications (e.g., improve potency/selectivity, multiple ligand design, protein-protein interactions, etc.) in drug discovery.
  
  
  RESULTS
  The readers will learn the strategies involved in scaffold design and the problems that they solve. They will also gain the understanding of the circumstances suitable for using scaffold design.
  
  
  CONCLUSIONS
  Scaffold is defined by the authors as a biological target dependent concept. Therapeutically useful scaffolds are limited and the identification of new scaffolds is sometimes required to overcome major optimization hurdles. However, depending on the promiscuity of the binding pocket of the target and the validity of the optimization protocol, finding better scaffolds can be a challenging task. Several strategies in scaffold discovery have emerged or matured owing to recent trends such as pursuit of targets from new proteomic families, lack of validated targets, advances in synthesis and biological assays and adoption of in vitro activity-driven screening paradigms.
authors: Abbott Laboratories, 100 Abbott Park Road, Abbott Park, IL 60064, USA  +1 847 935 4566 ;  +1 847 935 0310 ;  zhao_hongyu@hotmail.com.
authors: Hongyu
authors: H
authors: Zhao
authors: Irini
authors: I
authors: Akritopoulou-Zanze