Xanthine is widely used in the pharmaceutical industry as a precursor for the synthesis of various drugs, particularly those targeting respiratory and cardiovascular conditions. It serves as a key intermediate in the production of theophylline and caffeine, which are commonly used to treat asthma, bronchitis, and other respiratory disorders by relaxing bronchial muscles and improving airflow. Additionally, xanthine derivatives are utilized in medications for heart conditions due to their ability to enhance cardiac output and dilate blood vessels. In research, xanthine is employed as a substrate in enzymatic studies to understand metabolic pathways and enzyme functions, particularly those involving xanthine oxidase. It also finds applications in biochemical assays to measure enzyme activity and oxidative stress levels.