COc1cccc2c1C(=O)c1c(O)c3c(c(O)c1C2=O)C[C@@](O)(C(=O)CN1CCOCC1)C[C@@H]3OC1CC(N)C(O)C(C)O1.Cl
A lower number of pka indicates that the acid dissociates more entirely in water. What is pka of the molecule?