Using CC[C@H](C)[C@H](N)C(=O)N[C@@H](Cc1c[nH]cn1)C(=O)N[C@@H](CCCCNC(=O)OC(C)(C)C)C(=O)OC, CC(C)C[C@H](NC(=O)OCc1ccccc1)[C@@H](O)CC(=O)O to produce CC[C@H](C)[C@H](NC(=O)C[C@H](O)[C@H](CC(C)C)NC(=O)OCc1ccccc1)C(=O)N[C@@H](Cc1c[nH]cn1)C(=O)N[C@@H](CCCCNC(=O)OC(C)(C)C)C(=O)OC, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.