COc1ccc(CN2CCN(C(=O)C3CCC(CNS(=O)(=O)c4ccc(C)cc4)CC3)CC2)c(OC)c1OC
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?