['CO', 'CCOCCNS(=O)(=O)c1cn[nH]c1', 'CCOC', 'O=S(=O)(NCCO)c1cn[nH]c1', 'COCCO', 'CCNS(=O)(=O)c1cn[nH]c1', 'CCOCCOC', 'NS(=O)(=O)c1cn[nH]c1', 'COCCOCCN', 'O=[SH](=O)c1cn[nH]c1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1cn[nH]c1.