SPROUT,HIPPO and CAESA: Tools for de novo structure generation and estimation of synthetic accessibility

Summary Several components of a system for structure generation are now well developed. HIPPO is a program that characterises a receptor binding site for potential target sites within the cavity that can be used in de novo design. The target sites include simple and complex hydrogen bonds, covalent bonds and bonds to metal ions. The SPROUT program for structure generation consists of two main components: the first is skeleton generation, followed by atom substitution to convert the solution skeletons to molecules. A new method of skeleton generation is presented here, where part skeletons are grown outwards from each target site. The part skeletons are then connected together to form solution skeletons. Finally the CAESA program is described, that ranks the output from SPROUT according to ease of synthesis.