['CC(N)C(=O)NC(C)(C)C', 'O=CCOc1cccc([N+](=O)[O-])c1', 'CC(C)(C)N', 'CC(C=O)NC(=O)COc1cccc([N+](=O)[O-])c1', 'O=[N+]([O-])c1cccc(O)c1', 'CC(=O)NC(C)C(=O)NC(C)(C)C', 'O=[N+]([O-])c1ccccc1', 'CC(NC(=O)CO)C(=O)NC(C)(C)C', 'CCC(=O)NC(C)(C)C', 'NC(=O)COc1cccc([N+](=O)[O-])c1', 'CC(C)C', 'CC(NC(=O)COc1cccc([N+](=O)[O-])c1)C(N)=O']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.