Connection Tables Beilstein

Compounds are stored as connection tables (CT) in structure and reaction databases, e.g., Beilstein, Cmelin, CAS Registry, and CASREACT. 

ROSDAL. Linear notation scheme devised by the Beilstein Institute. It can contain just connection table information, or it may also contain atom coordinates. Several chemical information systems can convert ROSDAL strings to other structure file formats. 

The 12-digit Code. To illustrate this procedure, let us look at the example used above in Fig. 2 the structure is input, and the operation of the Beilstein System on the connection table is then carried out- The structure is recognised as being composed of three fragments (substructures), namely ... 

The structures of the Beilstein compounds are stored in connection tables (CT s) to allow a very flexible structure and substructure search. Since most commercially available structure/substructure handling programs such as MACCS (MDL) or DARC (Telesystemes/Questel) work on the basis of CT s, the Beilstein Registry Connection Table (BRCT) can be easily adapted for in-house systems. 

The computer translation of systematic chemical nomenclature into chemical structures is now possible. At least three groups have software which demonstrates this. Chemical Abstracts Service has for a long time used software running on mainframe computers to translate names in its style of nomenclature into connection tables. More recently, the Beilstein Institute has developed the VICA name interpreter for an IBM 3090 mainframe. This translates with a high success rate a wide range of names into a connection table using a dictionary of some 3000 name fragments. ... 

BRCT = Beilstein Registry Connection Table BRN = Beilstein Registry Number CAS = Chemical Abstracts Service CNOC = Commission on the Nomenclature of Organic Chemistry CT = connection table ICRS = Index Chemicus Registry System ISI = Institute for Scientific Information RN = CAS Registry Number SCN = Structure Code Number SSSR = smallest set of smallest rings WLN = Wiswesser Line-formula Notation. 

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