Using O=C(O)CN1C(=O)C(N[C@@H](CCCCNC(=O)OCc2ccccc2)C(=O)O)CCCc2ccccc21 to produce NCCCC[C@H](NC1CCCc2ccccc2N(CC(=O)O)C1=O)C(=O)O, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.