Using CC(=O)NC[C@H]1CN(c2ccc3c(c2)CSCC3)C(=O)O1, O to produce CC(=O)NC[C@H]1CN(c2ccc3c(c2)CS(=O)CC3)C(=O)O1, please predict the agent for this reaction in SMILES notation in \boxed{$SMILES1, SMILES2, ...} format.