C=C(CO)[C@H]1Cc2c(ccc3c2O[C@H]2COc4cc(OC)c(OC)cc4[C@@H]2C3=O)O1
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?