Tautomers represent a challenge for compound property calculations and cheminformatics tools. Tautomerism (WIKI) is especially tricky when aromatic groups are included in the molecules. Advanced tautomer generation software takes the stability and feasibility of possible tautomers into account (by means of multiple rules). Marvin can calculate tautomers very easily and provides rules such as charge protection, stereocenter protection, aromaticity protection, generation of canonical tautomers and the generation of major tautomer species.

(Allopurinol tautomers generated by ChemAxon Mview)
OFCNXPDARWKPPY-UHFFFAOYSA-N

(Allopurinol tautomers generated by NCGC Tautomer generator)
OFCNXPDARWKPPY-UHFFFAOYSA-N

Software Tools

• Marvin Tautomer - Chemaxon Tool [LINK]
• NCGC Tautomer generator - TRIPOD NIH [LINK]
• MS.Tautomer - Molecular Networks [LINK]
• QuacPac - OpenEye Software [LINK]
• SDwash - MOE Pipeline Tools [LINK]
• Others: Tautgen, Inchi Software, ACDLabs, Accelrys, SYMYX

Downloads

• Allopurinol Tautomers as [SDF] as [INCHI] and as [INCHIKey]

Literature

• So you think you understand tautomerism? [DOI]
• Tautomerism in chemical information management systems [DOI]
• Tautomerism in large databases [DOI] (A total of 680 million tautomers were calculated)