COc1ccc(NS(=O)(=O)c2ccc3oc(SC4CCOC4=O)nc3c2)cc1
An acid's negative base-10 logarithmic dissociation constant (pKa) follows directly from its underlying thermodynamics; the negative pKa is directly proportional to its standard Gibbs free energy change. What is the negative pKa value of this molecule?