Algorithmic N2S conversion

Our intention in this chapter is to examine the challenges of extracting identihers from chemistry-related documents and the conversion of those identihers into chemical structures. The authors of this work each have well over a decade of experience in chemical structure representation and systematic nomenclature. We have been deeply involved in the development of software algorithms and software for the generation of systematic names and the conversion of chemical identihers into chemical structures.9 Although we have our own biases concerning approaches to the problem of N2S conversion, we have done our utmost to be objective in our review of the subject and comparison of approaches and performance. 

The projects outlined above all focus on the extraction of chemical identifiers from text, but there is a clear dependence on the N2S conversion algorithms for the overall output of the various approaches. The remainder of this chapter will review the challenges associated with the development of N2S algorithms and how these can be addressed. 

This example demonstrates that one of the main challenges for an N2S conversion algorithm applied to data mining is the conversion of chemical names that are not strictly systematic, are ambiguous, or include typographical errors or misprints. 

One of the primary issues with systematic nomenclature is that some names can appear systematic in nature but, in fact, are not. They can have the expected structure of a chemical name generated according to a rules-based system but are false systematic names, at least in their specific context. When the N2S conversion algorithms... 

The first publication about the computer translation of chemical names was published by Garfield in 1961. In that article, he described the conversion of names into chemical formulas and initiated the path toward N2S algorithm development.45 Developments in 1967 at CAS provided internal procedures for the automatic conversion of CAS names into chemical diagrams.46 47 The first commercially available software program was CambridgeSoft s Name=Struct released in 1999,48 now patented,49 which was followed shortly by ACD/Labs ACD/Name to Structure product released in 2000.50 Two more commercial products are available Chemlnnovation s NameExpert51 and... 

Chemical nomenclature has a very large number of specific procedures to create chemical names, and many of these are not easily amenable to algorithmic representation, requiring significant investments in both development and validation time to develop automated procedures. Software developers of N2S engines prefer to support just the basic operations for conversion, at least at the early stages of development. 

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