Using CSCC[C@H](NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)OC(C)(C)C)C(=O)N[C@@H](CC(=O)O)C(=O)N[C@H](C)C(N)=O, CCCNC(=O)C(C)(N)CC(=O)[C@H](CC(=O)O)NC(=O)[C@@H](N)CCSC to produce CCCNC(=O)C(C)(N)CC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CCSC)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)OC(C)(C)C, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.