Linguistic measures of chemical diversity and the “keywords” of molecular collections

Computerized linguistic analyses have proven of immense value in comparing and searching through large text collections (“corpora”), including those deposited on the Internet – indeed, it would nowadays be hard to imagine browsing the Web without, for instance, search algorithms extracting most appropriate keywords from documents. This paper describes how such corpus-linguistic concepts can be extended to chemistry based on characteristic “chemical words” that span more than traditional functional groups and, instead, look at common structural fragments molecules share. Using these words, it is possible to quantify the diversity of chemical collections/databases in new ways and to define molecular “keywords” by which such collections are best characterized and annotated.