Tautomer Processing in the Beilstein Registry System

In a previous presentation [1] we described the Beilstein Registry Connection Table (BRCT) for organic compounds. This consists of a “list of lists”; certain lists are obligatory for each structure, eg. the “from” list which describes the connectivity of the structure graph, while other lists are optional and are only present when necessary, eg. non-Carbon atoms, charges and abnormal masses. In addition, a group of lists describes the configuration, when known, of asymmetric atoms and double bonds; another group of lists contains information about the tautomerism of the structure.