Oc1ccc(C[C@H]2CNC(=S)N2C[C@H]2CCCN2C[C@H](Cc2ccccc2)N2C[C@H](Cc3ccc(O)cc3)N(CC3CCCCCC3)C2=S)cc1
A lower number of negative pKa indicates that the acid dissociates more entirely in water. What is the negative pKa of this molecule?