Using CCCc1ccccc1OCC(O)COc1ccc2oc(C(=O)O)cc(=O)c2c1 to produce CCCc1ccccc1OCC(O)COc1ccc2oc(C(=O)[O-])cc(=O)c2c1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.