O=C(C[C@H]1C/C=C\C[C@H](NC(=O)OCC2c3ccccc3-c3ccccc32)C(=O)OC[C@@H]2CCCN2C1=O)N[C@H](CO)Cc1ccccc1
A lower number of negative pKa indicates that the acid dissociates more entirely in water. What is the negative pKa of this molecule?