7-(2-hydroxy-3-phenoxypropyl)-1,3-dimethyl-8-[(2E)-2-[(E)-3-(5-nitrofuran-2-yl)prop-2-enylidene]hydrazinyl]purine-2,6-dione

1,3-dimethyl-8-piperidin-1-yl-7H-purine-2,6-dione

1,3-dimethyl-2-oxo-8-pyridin-1-ium-1-ylpurin-6-olate

1,3,7-trimethyl-8-phenylpurine-2,6-dione