['CN', 'C[C@H](C=O)Sc1nc2ccccc2c2nc3ccccc3n12', 'CCC(=O)NC', 'Sc1nc2ccccc2c2nc3ccccc3n12', 'CNC(=O)[C@@H](C)S', 'c1ccc2c(c1)ncn1c3ccccc3nc21']
The Murcko scaffold (minmal number of connected rings) of <smiles></smiles> is c1ccc2c(c1)ncn1c3ccccc3nc21.