COc1ccc(-c2c3c(=O)n(C)c(=O)n(C)c3c3n2-c2ccccc2NC3c2ccc(O)cc2O)cc1
An acid's negative base-10 logarithmic dissociation constant (pka) follows directly from its underlying thermodynamics; pKa is directly proportional to its standard Gibbs free energy change. What is the pka value of this molecule?