are a group of
Alkaloid s that are commonly used for their effects as mild
Stimulant s and as
Bronchodilator s, notably in treating the symptoms of
Asthma . Their effects, however, are widespread and their
Therapeutic Range is narrow and so they are not the drug of choice in asthma treatment.
Methylated xanthine derivatives include
Caffeine ,
Theophylline , and
Theobromine (found mainly in
Chocolate ). These drugs
Inhibit Phosphodiesterase and
Antagonise Adenosine .
The core compound, xanthine, is a product on the pathway of
Purine degradation and is converted to
Hypoxanthine by the action of the
Xanthine Oxidase enzyme. Some people lack sufficient xanthine oxidase, and thus xanthine cannot be converted to uric acid. This rare
Genetic Disorder is called . Those with the disease have unusually high concentrations of xanthine in their blood and urine, which can lead to health problems such as
Renal Failure . There is no specific treatment; sufferers are advised by doctors to avoid foods high in purine and to maintain a high fluid intake.
Xanthines are
Purine derivatives and found very rarely in constituents of
Nucleic Acid s.
