['CC', 'Cc1cc([N+](=O)[O-])cc(S(=O)(=O)NCC#N)c1C', 'CC#N', 'CCNS(=O)(=O)c1cc([N+](=O)[O-])cc(C)c1C', 'CCNCC#N', 'Cc1cc([N+](=O)[O-])cc([SH](=O)=O)c1C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.