COc1ccc2c(c1)O[C@@H](c1ccc3c(c1)OCO3)[C@H](O)C2=O
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 negative pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the negative pKa value of this molecule?