Product Code Database
Xanthine ( or , from Ancient Greek ξανθός xanthós for its yellowish-white appearance; archaically xanthic acid; systematic name 3,7-dihydropurine-2,6-dione) is a purine base found in most human body tissues and fluids, as well as in other organisms. Several are derived from xanthine, including caffeine, theophylline, and theobromine.
Xanthine is a product on the pathway of purine degradation.
Xanthine is subsequently converted to uric acid by the action of the xanthine oxidase enzyme.
If swallowed, inhaled, or exposed to the eyes in high amounts, xanthines can be harmful, and they may cause an allergic reaction if applied topically.
However, different analogues show varying potency at the numerous subtypes, and a wide range of synthetic xanthines (some nonmethylated) have been developed searching for compounds with greater selectivity for phosphodiesterase enzyme or adenosine receptor subtypes.
Use and production
Xanthine is used as a drug precursor for human and animal medications, and is produced as a pesticide ingredient.
Clinical significance
Derivatives of xanthine (known collectively as xanthines) are a group of commonly used for their effects as mild and as , notably in the treatment of asthma or influenza symptoms. In contrast to other, more potent stimulants like sympathomimetic amines, xanthines mainly act to oppose the actions of adenosine, and increase alertness in the central nervous system.
Toxicity
Methylxanthines (Methylation xanthines), which include caffeine, aminophylline, IBMX, paraxanthine, pentoxifylline, theobromine, theophylline, and 7-methylxanthine (heteroxanthine), among others, affect the airways, increase heart rate and force of contraction, and at high concentrations can cause cardiac arrhythmias. In high doses, they can lead to convulsions that are resistant to anticonvulsants. Methylxanthines induce gastric acid and pepsin secretions in the gastrointestinal tract. Methylxanthines are metabolized by cytochrome P450 in the liver.
Pharmacology
In in vitro pharmacology studies, xanthines act as both competitive nonselective phosphodiesterase inhibitors and nonselective adenosine receptor antagonists. Phosphodiesterase inhibitors raise intracellular cAMP, activate PKA, TNF inhibitor synthesis, and leukotriene and reduce inflammation and innate immunity. Adenosine receptor antagonists inhibit sleepiness-inducing adenosine.
+ Examples of xanthine derivatives
!Name!!R1!!R2!!R3!!R8!!IUPAC nomenclature!!Found in Plants, animals Metabolite of caffeine and theobromine Cocoa bean (chocolate), yerba mate, Kola nut, guayusa Tea, Cocoa bean (chocolate), yerba mate, Kola nut Animals that have consumed caffeine Coffee, guarana, yerba mate, tea, Kola nut, guayusa, Cocoa bean (chocolate) 8-Chloro-1,3-dimethyl-7 H-purine-2,6-dione Synthetic pharmaceutical ingredient 8-Bromo-1,3-dimethyl-7 H-purine-2,6-dione Pamabrom diuretic medication Diprophylline CH3 CH3 C3H7O2 H 7-(2,3-Dihydroxypropyl)-1,3-dimethyl-3,7-dihydro-1 H-purine-2,6-dione Synthetic pharmaceutical ingredient IBMX CH3 Butyl group H H 1-Methyl-3-(2-methylpropyl)-7 H-purine-2,6-dione Uric acid H H H O 7,9-Dihydro-1 H-purine-2,6,8(3 H)-trione Byproduct of purine nucleotides metabolism and a normal component of urine
Pathology
People with rare , specifically xanthinuria and Lesch–Nyhan syndrome, lack sufficient xanthine oxidase and cannot convert xanthine to uric acid.
Possible formation in absence of life
Studies reported in 2008, based on 12C/13C of organic compounds found in the Murchison meteorite, suggested that xanthine and related chemicals, including the RNA component uracil, have been formed extraterrestrially. In August 2011, a report, based on NASA studies with meteorites found on Earth, was published suggesting xanthine and related organic molecules, including the DNA and RNA components adenine and guanine, were found in outer space.
See also
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