Ingvar Lagerstedt Poster

Evaluating Tautomer Standardization Rules using Tautobase

Ingvar Lagerstedt and Roger A. Sayle

NextMove Software

Tautobase[1] contains ratios for 1680 tautomer pairs, distilled from the work of Peter Taylor and Peter Kenny[2]. The reported ratios is a mix of experimental and estimated values. We presented here a partial implementation of these rules in rxnfix, a program for reaction normalisation. Issues discussed include:
– should some rules be ignored, i.e., when the distribution is close to 50-50
– how far can one extrapolate, i.e., between halogen or carbonyl substituents
– should only values from water be include, distribution is often very different in gas phase/apolar solvents
One early lesson is that it is better to apply rules on fully kekulized structures, then on structures just indicating aromatic bonds.

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