对苯基苯酚

1,3-dimethyl-8-(E)-styryl-3,7-dihydro-1H-purine-2,6-dione

8-hydrazinyl-1,3-dimethyl-7-prop-2-enylpurine-2,6-dione

茶碱

8-溴-1,3,7-三甲基嘌呤-2,6-二酮