COc1ccc(OC)c(NS(=O)(=O)c2ccc3nc(C)n(NS(=O)(=O)c4cc(OC)ccc4OC)c(=O)c3c2)c1
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?