Skip to main content
. Author manuscript; available in PMC: 2021 Apr 1.
Published in final edited form as: J Comput Aided Mol Des. 2020 Feb 27;34(4):335–370. doi: 10.1007/s10822-020-00295-0

Figure 11. The tautomer and resonance structure choice resulted in discrepancies in the reference calculations.

Figure 11.

Shown here are calculated values for different input structures using the reference direct transfer free energy method. The uncertainties of the log P predictions were calculated as the standard error of the mean (SEM) of three replicate predictions. Structures labelled as SM08, SM11, and SM14 are based on input SMILES provided in SAMPL6 log P Challenge instructions. Three microstates shown for SM08 are different tautomers. SM08 (SM08_micro011) and SM08_micro010 are carboxylic acids, while SM08_micro008 is a carboxylate ion. SM08 (SM08_micro011) has a carbonyl group in the ring, while SM08_micro008 and SM08_micro010 have a hydroxyl in the ring. Structures pertaining to SM11 and SM14 are different resonance hybrids of the same tautomer (neutral microstate). Enumeration of all theoretically possible neutral tautomers of SAMPL6 molecules can be found in the SAMPL6 GitHub Repository (https://github.com/samplchallenges/SAMPL6/tree/master/physical_properties/pKa/microstates).