Structure Search 
This tool provides possibilities to search for isomers, similar molecules or ligands which contain the drawed structure.
In order to reduce high loading times, the search comprises two steps. The first step, used as a prefilter, is the fingerprint scan of all BRENDA ligand structures.
Fingerprints are a type of structural keys consisting of a series of binary digests (bits). Each bit in a fingerprint represents a path (sequence of atoms and bonds) up to length 8 in the molecule.
In the time consuming second step all found structures are tested for subgraph or isomorphism matching. For similarity searches a fingerprint based tanimoto coefficient is used as a quantitative measure of similarity between two molecules.
To restrict loading times for the subgraph/ismomorphism matching algorithm, a maximal search time can be selected. You can increase this value in the search form to get more results especially in the substructure search. The percentage of molecules checked by the matching algorithm within the previously defined time can be found above the result table.
