TY - JOUR T1 - Octanol-water partition coefficient measurements for the SAMPL6 Blind Prediction Challenge JF - bioRxiv DO - 10.1101/757393 SP - 757393 AU - Mehtap Işık AU - Dorothy Levorse AU - David L. Mobley AU - Timothy Rhodes AU - John D. Chodera Y1 - 2019/01/01 UR - http://biorxiv.org/content/early/2019/09/08/757393.abstract N2 - Partition coefficients describe the equilibrium partitioning of a single, defined charge state of a neutral solute between two immiscible phases, typically a neutral solute. Octanol-water partition coefficients (Kow), or their logarithms (log P), are frequently used as a measure of lipophilicity in drug discovery. The partition coefficient is a physicochemical property that captures the thermodynamics of relative solvation between aqueous and nonpolar phases, and therefore provides an excellent test for physics-based computational models that predict properties of pharmaceutical relevance such as protein-ligand binding affinities or hydration/solvation free energies. The SAMPL6 Part II Octanol-Water Partition Coefficient Prediction Challenge used a subset of kinase inhibitor fragment-like compounds from the SAMPL6 pKa Prediction Challenge in a blind experimental benchmark. Following experimental data collection, the partition coefficient dataset was kept blinded until all predictions were collected from participating computational chemistry groups. A total of 91 submissions were received from 27 participating research groups. This paper presents the octanol-water log P dataset for this SAMPL6 Part II Partition Coefficient Challenge, which consisted of 11 compounds (six 4-aminoquinazolines, two benzimidazole, one pyrazolo[3,4-d]pyrimidine, one pyridine, one 2-oxoquinoline substructure containing compounds) with log P values in the range of 1.95–4.09. We describe the potentiometric log P measurement protocol used to collect this dataset using a Sirius T3, discuss the limitations of this experimental approach, and share suggestions for future log P data collection efforts for the evaluation of computational methods. ER -