Using O=C(O)CN1CCN(CC(=O)O)CCN([C@H](CO)[C@H](O)CO)CCN(CC(=O)O)CC1 to produce O=C(O)CN1CCN(CC(=O)O)CCN(C(CO)C(O)CO)CCN(CC(=O)O)CC1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.