Xanthine is a chemical compound that is naturally found in some foods and beverages. It is also used in certain medications to treat conditions such as asthma and gout. Some common synonyms for xanthine include theobromine, caffeine, and theophylline. Theobromine is found in chocolate and tea and is similar in structure and effects to caffeine, which is found in coffee and energy drinks. Theophylline is often used to treat respiratory illnesses and is found in tea and cocoa beans. Other synonyms for xanthine include methylxanthines, purine alkaloids, and 1,3-dimethylxanthine. These compounds are often found together in foods and beverages and have similar effects on the body.