Using CCOC(=O)C[C@H](NC(=O)CN1CC[C@H](CCc2ccc3c(n2)NCCC3)C1=O)c1ccc2c(c1)OCC2 to produce O=C(O)C[C@H](NC(=O)CN1CC[C@H](CCc2ccc3c(n2)NCCC3)C1=O)c1ccc2c(c1)OCC2, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.