Similarity searching using REACCS

Similarity searching in the reaction and molecule domain is applied to the design and development of a hypothetical bioactive compound. Potential synthetic pathways are generated utihsing reaction and molecule similarity features in REACCS. Lead optimisation of the target compound is made possible by similarity searches over a database of compounds of known activity and by subsequent manipulation of the results. It is shown that similarity searching can be used as a powerful, complementary tool in the design of new chemical compounds. 

Similarity searching in reaction databases has gained widespread interest since it became available (in REACCS and ORAC) about two years ago. The definition of similarity of reactions in these reaction retrieval systems is based on common substructural features in the reaction centres and in the reactants. Without doubt, these definitions of reaction similarity are of great usefulness. However, we wanted to broaden the discussion of reaction similarity and search for additional helpful ideas. To achieve this we took a totally different approach to specify the similarity of reactions. Our approach is based on the idea that chemists often want to know the exact conditions for running a reaction. We assumed that similar reactions should be those that proceed under similar reaction conditions. 

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