pKa

SAMPL7 pK_a Prediction Challenge

The SAMPL7 pK_a Challenge consists of predicting relative free energies between microstates to determine the pK_a of 22 molecules. Free energies were chosen rather than pK_a values given the recent work of Gunner et al.. All possible tautomers of each ionization (charge) state are defined as distinct protonation microstates. Our aim is to evaluate how well current pK_a prediction methods perform with these 22 molecules through blind predictions. Challenge participants are asked to predict free energy differences between microstates. Challenge organizers have a reference microstate for each compound, and all free energies must be predicted relative to this reference state, as detailed in the challenge instructions linked below. This challenge is optional and will be run at the same time as the log P and permeability challenge (both of which are also optional).

Instructions for the pK_a challenge: pKa_challenge_instructions.md

Submission template for the pK_a challenge: submission_template/pKa_prediction_template.csv

We would like to note that compounds SM35, SM36 and SM37 are enantiopure and have a chiral center. All other compounds are not chiral. The version of these compounds with specified chirality should be used; refer to challenge instructions for more details.

Experimental pK_a measurements will made available after the challenge deadline.

Manifest

• microstates/ - This directory contains .CSV files that list microstate IDs and canonical isomeric SMILES of microstates. Files are separated by molecule ID. Updated microstates and their microstate IDs can be found in SMXX_microstates.csv files.
• submission_template/pKa_prediction_template.csv - An empty prediction submission template file.
• example_submission_file/pKa-DanielleBergazinExampleFile-1.csv - An example submission file filled with random values to illustrate expected format.
• pKa_challenge_instructions.md - Instructions for the pK_a challenge.
• transition_networks/ - This directory contains transition networks of the challenge molecules in .PDF and .PPTX format.
• analysis: Contains participant submissions and analysis results.