COc1ccc(NC(=O)Nc2cccc3c2O[C@@H](CN(C)CC2CCCCC2)[C@@H](C)CN([C@H](C)CO)C3=O)cc1
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?