SwissBioisostere provides access to a knowledge and structural database of molecular replacements. We hope it will be useful, for example but not exclusively, for hit finding and lead optimization in drug discovery.

Two types of queries are possible :

• The tab I want to search for possible replacements for a fragment
  ( e.g. all replacing fragments for a morpholine ring )
  
  Input the fragment in the sketcher with one, two or three attachment points tagged R₁, R₂ and R₃ using the 'Smart R-group' button. Then click 'Query Database'.


• The tab I want to get information on a given molecular replacement
  ( e.g. analysis of replacing morpholine by 3-pyridine )
  
  Input the fragment to be replaced in the left-hand sketcher and the replacing fragment on the right-hand sketcher. Add one, two or three attachement points (R1, R2, R3) on the left-hand fragment, and the corresponding ones on the right-hand fragment with the 'Smart R-group' buttons. Then click 'Query Database'.

Examples can be found here.