['C[C@H](C=O)NC(N)=O', 'CC[C@@H](C)c1ccc(N)cc1', 'NC=O', 'CC[C@@H](C)c1ccc(NC(=O)[C@@H](C)N)cc1', 'NC(N)=O', 'CCC(=O)Nc1ccc([C@H](C)CC)cc1', 'C[C@@H](NC(N)=O)C(N)=O', 'CC[C@@H](C)c1ccccc1', 'CCCC', 'C[C@@H](NC(N)=O)C(=O)Nc1ccccc1']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccccc1.