SUBSTRUCTURE SEARCHING METHODS - OLD AND NEW

The first algorithms for chemical substructure search on computer were developed in the 1950s and 1960s and were widely adopted in systems developed through the 1970s and early 1980s. Since the mid- 1980s there has been significant activity in the development of novel algorithms, which have enabled rapid searches to be made in very large databases. The principles underlying the ''classic'' algorithms are described, and these are contrasted with more recent approaches. Brief mention is made of current research work.