['C[SH](=O)=O', 'O=[N+]([O-])c1c(F)cccc1NC1CCCNC1', 'O=[N+]([O-])c1ccccc1F', 'CS(=O)(=O)N1CCCC(N)C1', 'CS(=O)(=O)N1CCCCC1', 'Nc1cccc(F)c1[N+](=O)[O-]']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc(NC2CCCNC2)cc1.