['CO', 'CCOc1ccc(S(=O)(=O)NNC(=O)CC(C)C)cc1', 'CCOC', 'CC(C)CC(=O)NNS(=O)(=O)c1ccc(O)cc1', 'COCCO', 'CC(C)CC(=O)NNS(=O)(=O)c1ccccc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.