CCC1CCc2c(sc3nc(SCC(=O)NCc4ccco4)n(-c4ccccc4)c(=O)c23)C1
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?