COc1ccc(CN(C(=O)CN2C(=O)c3ccccc3S2(=O)=O)C(C(=O)NCC2CCCO2)c2ccco2)cc1
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?