['CO', 'O=[N+]([O-])C[C@H](c1ccccc1)c1cccs1', 'c1ccsc1', 'COc1ccc(CC[N+](=O)[O-])cc1', 'COc1ccccc1', 'O=[N+]([O-])CCc1cccs1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(Cc2cccs2)cc1.