O=C(CN1C(=O)/C(=C/c2ccco2)SC1=S)Nc1ccc(O)c(C(=O)O)c1
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?