5-imino-1,3-dimethylimidazolidine-2,4-dione

1,3,7-trimethyl-8-(3-methylbutoxy)purine-2,6-dione

[2,2’]-双噻吩-5,5‘-二甲醛

1,3,7-trimethyl-8-(5-formylthiophen-2-yl)xanthine

1,3,7-trimethyl-8-propan-2-ylpurine-2,6-dione