There are various synonyms for Xanthin, which is a yellow crystalline compound commonly found in plants and animal tissue. Some of the alternate names for Xanthin include xanthine, oxidized xanthine, methylxanthine, and theophylline. Theophylline is a derivative of Xanthin and is used in the treatment of respiratory diseases such as asthma and chronic obstructive pulmonary disease (COPD). Methylxanthine is another derivative of Xanthin that has stimulant effects on the central nervous system. Other related compounds include caffeine, theobromine, and paraxanthine. While these compounds have similar chemical structures, they differ in their properties and applications.