O=C(OC1C(Oc2ccccc2COC(=O)C2(O)C=CCCC2=O)OC(CO)C(O)C1O)c1ccccc1
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?