CC(=O)OCC1=C(C(=O)[O-])N2C(=O)[C@@H](NC(=O)Cc3cccs3)[C@@H]2SC1.[Na+]
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?