COC(=O)C1C(O)C(C)C(=O)C(C)/C=C\C=C(C)C(=O)Nc2c(C)c(OC(C)=O)c3c(c2O)C(=O)C(C)=C2OCOC(=C23)C(C)=CC(C)(O)C(O)C(C)C1O
A lower number of pka indicates that the acid dissociates more entirely in water. What is pka of the molecule?