CCn1nccc1NC(=O)c1ccc2sc([C@@H]3O[C@H](CO)[C@H](O)[C@H](O)[C@H]3O)nc2c1
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?