COc1ccc(CCNC(=O)c2ccc3c(SCC(=O)O)c4c(nc3c2)CCCC4)cc1OC
The negative base-10 logarithmic of dissociation constant (pka) for an acid is a direct consequence of the underlying thermodynamics of the dissociation reaction; the pKa value is directly proportional to the standard Gibbs free energy change for the reaction. What is the pka value of this molecule?