Xanthine

Methylxanthine

Xanthine is a purine base found in most human body tissues and fluids and in other organisms. It plays a crucial role in the metabolism of nucleotides and is a precursor to uric acid.

Biochemistry

Xanthine is derived from the deamination of guanine and the oxidation of hypoxanthine. It is subsequently oxidized by the enzyme xanthine oxidase to form uric acid, which is then excreted in the urine. This process is part of the purine metabolism pathway.

Medical Relevance

Elevated levels of xanthine can lead to a condition known as xanthinuria, which is characterized by the excessive excretion of xanthine in the urine. This can result in the formation of xanthine stones in the kidneys and urinary tract.

Sources

Xanthine and its derivatives, such as caffeine, theobromine, and theophylline, are found in various foods and beverages, including coffee, tea, and chocolate.

Derivatives

Xanthine derivatives are known as xanthines. These compounds have various pharmacological effects and are used in the treatment of conditions such as asthma and chronic obstructive pulmonary disease (COPD). The most well-known xanthine derivatives include:

• Caffeine
• Theobromine
• Theophylline

See also

• Purine
• Nucleotide
• Uric acid
• Xanthine oxidase
• Xanthinuria