COc1cccc(CNC(=O)C(CCSC)NS(=O)(=O)c2ccc3c(c2)oc(=O)n3C)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?