Registry and search of chemical compounds on graphics display

The registry and substructure search component of in-house system SPHINCS (Structure /Property Handling Information Network for Chemical Substances) has been developed. For registry, a chemical structure is constructed on a graphics display by use of templates (e.g., 6N for pyridine, NH2 for amino group) and commands (e.g., BOND, EXCHANGE, DELETE). The generated connection table and atom coordinates are stored in a file. In a search, a query substructure is drawn on a graphics display. Special atom symbols (e.g., A for any atoms but hydrogen, HT for hetero atoms) can be used to represent the generic nature of a search. More than 1000 fragment codes (elements, rings, chains and augmented atoms), generated by computer analysis of connection tables, are used as primary search screens. An atom—bond—atom search program removes false drop structures. The structures retrieved are displayed in forms familiar to chemists with use of templates.