CC(C)C[C@H]1CNC(=S)N1C[C@H]1CCCN1C[C@H](Cc1ccccc1)N1C[C@H](Cc2ccc(O)cc2)N(CCc2ccccc2)C1=S
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?