C=C[C@H]1[C@H](OC2OC(CO)C(O)C(O)C2O)OC=C(C(=O)OC)[C@H]1C[C@H]1CC(=O)C[C@H](CC(=O)CCc2ccc(O)cc2)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?