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| Names | |||
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| Preferred IUPAC name 3,7-Dihydro-1H-purine-2,6-dione | |||
| Other names 1H-Purine-2,6-dione | |||
| Identifiers | |||
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3D model (JSmol) | |||
| ChEBI | |||
| ChEMBL | |||
| ChemSpider |
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| DrugBank |
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| ECHA InfoCard | 100.000.653 | ||
| KEGG |
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| UNII | |||
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| Properties | |||
| C5H4N4O2 | |||
| Molar mass | 152.11 g/mol | ||
| Appearance | White solid | ||
| Melting point | decomposes | ||
| 1 g/ 14.5 L @ 16 °C 1 g/1.4 L @ 100 °C | |||
| Hazards | |||
| NFPA 704 (fire diamond) | |||
Except where otherwise noted, data are given for materials in theirstandard state (at 25 °C [77 °F], 100 kPa). | |||
Xanthine (/ˈzænθiːn/ or/ˈzænθaɪn/, fromAncient Greekξανθόςxanthós'yellow' for its yellowish-white appearance; archaicallyxanthic acid; systematic name3,7-dihydropurine-2,6-dione) is apurinebase found in most human body tissues and fluids, as well as in other organisms.[2] Severalstimulants are derived from xanthine, includingcaffeine,theophylline, andtheobromine.[3][4]
Xanthine is a product on the pathway ofpurine degradation.[2]
Xanthine is subsequently converted touric acid by the action of thexanthine oxidase enzyme.[2]
Xanthine is used as adrugprecursor for human and animal medications, and is produced as apesticide ingredient.[2]
Derivatives of xanthine (known collectively asxanthines) are a group ofalkaloids commonly used for their effects as mildstimulants and asbronchodilators, notably in the treatment ofasthma orinfluenza symptoms.[2] In contrast to other, more potent stimulants likesympathomimetic amines, xanthines mainly act to oppose the actions ofadenosine, and increase alertness in thecentral nervous system.[2]
Methylxanthines (methylated xanthines), which includecaffeine,aminophylline,IBMX,paraxanthine,pentoxifylline,theobromine,theophylline, and7-methylxanthine (heteroxanthine), among others, affect the airways, increase heart rate and force of contraction, and at high concentrations can cause cardiac arrhythmias.[2] In high doses, they can lead to convulsions that are resistant to anticonvulsants.[2] Methylxanthines inducegastric acid andpepsin secretions in thegastrointestinal tract.[2] Methylxanthines are metabolized bycytochrome P450 enzymes in the liver.[2]
If swallowed, inhaled, or exposed to the eyes in high amounts, xanthines can be harmful, and they may cause anallergic reaction if appliedtopically.[2]
Inin vitropharmacological studies, xanthines act as both competitive nonselectivephosphodiesterase inhibitors and nonselectiveadenosine receptor antagonists.Phosphodiesterase inhibitors raise intracellularcAMP, activatePKA,inhibit TNF-α synthesis,[2][5][4] andleukotriene[6] andreduce inflammation andinnate immunity.[6]Adenosine receptor antagonists[7] inhibit sleepiness-inducingadenosine.[2]
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 forphosphodiesterase enzyme oradenosine receptor subtypes.[2][8][7][9][10][11]
| Name | R1 | R2 | R3 | R8 | IUPAC nomenclature | Found in |
|---|---|---|---|---|---|---|
| Xanthine | H | H | H | H | 3,7-Dihydro-purine-2,6-dione | Plants, animals |
| 7-Methylxanthine | H | H | CH3 | H | 7-methyl-3H-purine-2,6-dione | Metabolite of caffeine and theobromine |
| Theobromine | H | CH3 | CH3 | H | 3,7-Dihydro-3,7-dimethyl-1H-purine-2,6-dione | Cacao (chocolate),yerba mate,kola,guayusa |
| Theophylline | CH3 | CH3 | H | H | 1,3-Dimethyl-7H-purine-2,6-dione | Tea,cacao (chocolate),yerba mate,kola |
| Paraxanthine | CH3 | H | CH3 | H | 1,7-Dimethyl-7H-purine-2,6-dione | Animals that have consumed caffeine |
| Caffeine | CH3 | CH3 | CH3 | H | 1,3,7-Trimethyl-1H-purine-2,6(3H,7H)-dione | Coffee,guarana,yerba mate,tea,kola,guayusa,Cacao (chocolate) |
| 8-Chlorotheophylline | CH3 | CH3 | H | Cl | 8-Chloro-1,3-dimethyl-7H-purine-2,6-dione | Synthetic pharmaceutical ingredient |
| 8-Bromotheophylline | CH3 | CH3 | H | Br | 8-Bromo-1,3-dimethyl-7H-purine-2,6-dione | Pamabrom diuretic medication |
| Diprophylline | CH3 | CH3 | C3H7O2 | H | 7-(2,3-Dihydroxypropyl)-1,3-dimethyl-3,7-dihydro-1H-purine-2,6-dione | Synthetic pharmaceutical ingredient |
| IBMX | CH3 | C4H9 | H | H | 1-Methyl-3-(2-methylpropyl)-7H-purine-2,6-dione | |
| Uric acid | H | H | H | O | 7,9-Dihydro-1H-purine-2,6,8(3H)-trione | Byproduct ofpurine nucleotides metabolism and a normal component of urine |
People with raregenetic disorders, specificallyxanthinuria andLesch–Nyhan syndrome, lack sufficient xanthine oxidase and cannot convert xanthine touric acid.[2]
Studies reported in 2008, based on12C/13Cisotopic ratios oforganic compounds found in theMurchison meteorite, suggested that xanthine and related chemicals, including theRNA componenturacil, have been formedextraterrestrially.[12][13] In August 2011, a report, based onNASA studies withmeteorites found on Earth, was published suggesting xanthine and related organic molecules, including theDNA andRNA componentsadenine andguanine, were found inouter space.[14][15][16]
