Purines are a class of chemical compounds, with various derivatives containing a variation of the same basic structure. Included in this group are guanine and adenine, which are components of nucleic acids.

All naturally occurring purines are a variation on the same basic structure. Derivatives or structurally related compounds include theophylline and caffeine.

Purines play a variety of important roles in the system: For example, they act as messengers in cellular signaling for muscle contraction and nerve conduction. They help rid cells of excess nitrogen.

Purines act as antioxidants, helping to protect cells from agents which cause cancer. In addition, they work as the information molecules in genes, helping to process the conversion of genes to proteins. They even work as energy transducers, assisting in the conversion of food to energy.

Uric acid is the end product of purines. It serves no bichemical function. Once uric acid is formed, it is usually eliminated from the body.

About one third of the uric acid normally produced in the body comes from food, with the remainder being produced through normal metabolism.

The final stages of purine metabolism include hypoxanthine to xanthine, and then from xanthine to uric acid. These are accomplished by the enzyme xanthine oxidase. Many gout patients take the xanthine oxidase inhibitor, allopurinol. This medication helps to prevent purines from ultimately metabolizing into uric acid.