NC(=O)C(CC(=O)O)NC(=O)[C@@H]1CCOc2c(I)cc([N+](=O)[O-])cc2C(=O)N[C@@H](CO)C(=O)N[C@@H](Cc2ccc(O)cc2)C(=O)N1
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?