COc1ccc(OC)c(-n2c(SCC(=O)Nc3cccc(S(N)(=O)=O)c3)nc3ccccc3c2=O)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?