COc1cc2c(c(OC)c1OC)C(=O)c1c(O)cc(C)c(OC)c1C2=O
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?