['NC=O', 'COc1ccc(OC)c(S(N)(=O)=O)c1', 'CO', 'COc1ccccc1S(=O)(=O)NC(N)=O', 'COc1cccc(S(=O)(=O)NC(N)=O)c1', 'NC(N)=O', 'COc1ccc(OC)c([SH](=O)=O)c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.