4,5-diamino-9-(β-D-ribofuranosyl)pyrrolo<2,3-d:5,4-d'>dipyrimidine

4-amino-9-(β-D-ribofuranosyl)pyrrolo<2,3-d:5,4-d'>dipyrimidine-5,7-dithione

4-amino-9-(β-D-ribofuranosyl)-pyrimido<5,4-f>pyrrolo<2,3-d>pyrimidin-5-7-dione

4-Amino-9-(β-D-ribofuranosyl)pyrrolo<2,3-d:5,4-d'>-5-thioxodipyrimidin-7-one

4-Amino-5-(methylthio)-9-(β-D-ribofuranosyl)pyrrolo<2,3-d:5,4-d'>dipyrimidin-7-one