['Nc1ccccc1[N+](=O)[O-]', 'CN(CCC=O)CC(=O)NC(C)(C)C', 'CC(C)(C)N', 'CN(CC=O)CCC(=O)Nc1ccccc1[N+](=O)[O-]', 'CNCC(=O)NC(C)(C)C', 'CCC(=O)Nc1ccccc1[N+](=O)[O-]', 'CC(=O)NC(C)(C)C', 'CNCCC(=O)Nc1ccccc1[N+](=O)[O-]', 'CC(C)C', 'CN(CCC(=O)Nc1ccccc1[N+](=O)[O-])CC(N)=O', 'O=[N+]([O-])c1ccccc1', 'CN(CCC(N)=O)CC(=O)NC(C)(C)C']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.