COc1ccc(C2c3[nH]c4ccccc4c3C[C@H]3C(=O)N(c4ccccc4C(=O)N4CCC(C(=O)O)CC4)C(=O)N23)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?