COc1ccc(NC(=O)N(C)C[C@H]2Oc3ccc(NC(=O)Nc4ccc5c(c4)OCO5)cc3C(=O)N([C@H](C)CO)C[C@@H]2C)cc1
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?