CC(C)C[C@H]1CNC(=S)N1CC1CCCN1C[C@H](Cc1ccc(O)cc1)N1C[C@H](Cc2ccccc2)N(CC2CCCCC2)C1=S
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?