2-[(4-amino-1,3-dimethyl-2,6-dioxopyrimidin-5-yl)amino]acetonitrile

1,3-dimethyl-6,7-diphenylpteridine-2,4-dione

1,3-dimethyl-7-phenylpteridine-2,4-dione

4,6-二甲基[1,2,5]噻二唑并[3,4-d]嘧啶-5,7(4H,6H)-二酮

1,3,7,9-tetramethylpyrimido[5,4-g]pteridine-2,4,6,8-tetrone