Database organization and searching with E-State indices

The electrotopological state (E-State) and its extension, the atom-type E-State, is presented as a representation of atom and molecular fragment structure useful for chemical database organization and management. An approach to database organization, using substituted esters and benzene derivatives as examples, reveals the descriptive power of the E-State paradigm. With a database, organized on the basis of structural relationships as described here, it is possible to search for similar molecular structures with potential for comparable activity. The searches using the atom-type E-State indices are demonstrated with several examples.