Xanthine: Difference between revisions

| IUPACNamePIN = 3,7-DihydropurineDihydro-1''H''-purine-2,6-dione

| RPhrasesHPhrases =

| SPhrasesPPhrases =

| RSPhrasesGHS_ref =

'''Xanthine''' ({{IPAc-en|ˈ|z|æ|n|θ|iː|n}} or {{IPAc-en|ˈ|z|æ|n|θ|aɪ|n}}, from [[Ancient Greek]] ξανθός ''xanthós'' "yellow" due to its yellowish-white appearance; archaically '''xanthic acid'''; systematic name '''3,7-dihydropurine-2,6-dione''') is a [[purine]] [[base (genetics)|base]] found in most human body tissues and fluids, andas well as in other organisms.<ref name="pubchem">{{cite web |title=Xanthine, CID 1188 |url=https://pubchem.ncbi.nlm.nih.gov/compound/1188 |publisher=PubChem, National Library of Medicine, US National Institutes of Health |access-date=28 September 2019 |date=2019}}</ref> Several [[stimulant]]s are derived from xanthine, including [[caffeine]], [[Theophylline|theophylline]], and [[theobromine]].<ref name="isbn0-8493-2647-8">{{cite book | author = Spiller, Gene A. | title = Caffeine | publisher = CRC Press | location = Boca Raton | year = 1998 | isbn = 0-8493-2647-8 }}</ref><ref name=":0">{{Cite book|last=Katzung|first=Bertram G.|title=Basic & Clinical Pharmacology|publisher=Paramount Publishing|year=1995|isbn=0-8385-0619-4|location=East Norwalk, Connecticut|pages=310, 311}}</ref>

'''Methylxanthines''' ([[Methylation|Methylatedmethylated]] xanthines (methylxanthines), which include [[caffeine]], [[aminophylline]], [[IBMX]], [[paraxanthine]], [[pentoxifylline]], [[theobromine]], [[theophylline]], and [[theophylline7-methylxanthine]] (heteroxanthine), affectamong notothers, onlyaffect the airways, but stimulateincrease heart rate, and force of contraction, and cardiac arrhythmias at high concentrations can cause cardiac arrhythmias.<ref name=pubchem/> In high doses, they can lead to convulsions that are resistant to anticonvulsants.<ref name=pubchem/> Methylxanthines induce [[gastric acid]] and [[pepsin]] secretions in the [[gastrointestinal tract]].<ref name=pubchem/> Methylxanthines are metabolized by [[cytochrome P450]] in the liver.<ref name=pubchem/>

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|phosphodiesterase enzyme]] or [[adenosine receptor]] subtypes.<ref name=pubchem/><ref name="pmid3806581">{{cite journal |vauthors=Daly JW, Padgett WL, Shamim MT | title = Analogues of caffeine and theophylline: effect of structural alterations on affinity at adenosine receptors | journal = Journal of Medicinal Chemistry | volume = 29 | issue = 7 | pages = 1305–8 |date=July 1986 | pmid = 3806581 | doi = 10.1021/jm00157a035}}</ref><ref name="pmid3588607">{{cite journal |vauthors=Daly JW, Jacobson KA, Ukena D | title = Adenosine receptors: development of selective agonists and antagonists | journal = Progress in Clinical and Biological Research | volume = 230 | pages = 41–63 | year = 1987 | pmid = 3588607 }}</ref><ref name="pmid1658821">{{cite journal |vauthors=Daly JW, Hide I, Müller CE, Shamim M | title = Caffeine analogs: structure-activity relationships at adenosine receptors | journal = Pharmacology | volume = 42 | issue = 6 | pages = 309–21 | year = 1991 | pmid = 1658821 | doi = 10.1159/000138813| url = https://zenodo.org/record/1235428}}</ref><ref name="pmid17668454">{{cite journal |vauthors=González MP, Terán C, Teijeira M | title = Search for new antagonist ligands for adenosine receptors from QSAR point of view. How close are we? | journal = Medicinal Research Reviews | volume = 28 | issue = 3 | pages = 329–71 |date=May 2008 | pmid = 17668454 | doi = 10.1002/med.20108 | s2cid = 23923058 }}</ref><ref name="pmid18181659">{{cite journal |vauthors=Baraldi PG, Tabrizi MA, Gessi S, Borea PA | title = Adenosine receptor antagonists: translating medicinal chemistry and pharmacology into clinical utility | journal = Chemical Reviews | volume = 108 | issue = 1 | pages = 238–63 |date=January 2008 | pmid = 18181659 | doi = 10.1021/cr0682195 }}</ref>

| [[Caffeine7-Methylxanthine]]||H||H||[[Methyl group|CH₃]]||CH₃||CH₃||H||1,3,7-Trimethylmethyl-13''H''-purine-2,6(3''H'',7''H'')-dione||[[Coffee]],Metabolite [[guarana]],of [[yerbacaffeine mate]],and [[tea]], [[Kola nut|kola]], [[guayusa]]theobromine

People with the rare [[genetic disorder]]s, specifically [[xanthinuria]] and [[Lesch–Nyhan syndrome]], lack sufficient xanthine oxidase and cannot convert xanthine to [[uric acid]].<ref name=pubchem/>

Studies reported in 2008, based on ¹²C/¹³C [[isotopic ratio]]s of [[organic compounds]] found in the [[Murchison meteorite]], suggested that xanthine and related chemicals, including the [[RNA]] component [[uracil]], have been formed [[Extraterrestrial materials|extraterrestrially]].<ref name="Murch_base">{{Cite journal | last1 = Martins | first1 = Z. | last2 = Botta | first2 = O. | last3 = Fogel | first3 = M. L. | last4 = Sephton | first4 = M. A. | last5 = Glavin | first5 = D. P. | last6 = Watson | first6 = J. S. | last7 = Dworkin | first7 = J. P. | last8 = Schwartz | first8 = A. W. | last9 = Ehrenfreund | first9 = P. | title = Extraterrestrial nucleobases in the Murchison meteorite | doi = 10.1016/j.epsl.2008.03.026 | journal = Earth and Planetary Science Letters | volume = 270 | issue = 1–2 | pages=130–136 | year = 2008 | bibcode=2008E&PSL.270..130M|arxiv = 0806.2286 | s2cid = 14309508 }}</ref><ref>{{Cite web|author=[[Agence France-Presse|AFP]] Staff |title=We may all be space aliens: study |date=13 June 2008 |url=http://afp.google.com/article/ALeqM5j_QHxWNRNdiW35Qr00L8CkwcXyvw |publisher=[[Agence France-Presse|AFP]] |access-date=2011-08-14 |url-status=dead |archive-url=https://web.archive.org/web/20080617213441/http://afp.google.com/article/ALeqM5j_QHxWNRNdiW35Qr00L8CkwcXyvw |archive-date=June 17, 2008 }}</ref> 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]].<ref name="Callahan">{{Cite journal | last1 = Callahan | first1 = M. P. | last2 = Smith | first2 = K. E. | last3 = Cleaves | first3 = H. J. | last4 = Ruzicka | first4 = J. | last5 = Stern | first5 = J. C. | last6 = Glavin | first6 = D. P. | last7 = House | first7 = C. H. | last8 = Dworkin | first8 = J. P. | doi = 10.1073/pnas.1106493108 | title = Carbonaceous meteorites contain a wide range of extraterrestrial nucleobases | journal = Proceedings of the National Academy of Sciences | volume = 108 | issue = 34 | pages = 13995–8 | year = 2011 | pmid = 21836052| pmc = 3161613| bibcode = 2011PNAS..10813995C | doi-access = free }}</ref><ref name="Steigerwald">{{cite web |last=Steigerwald |first=John |title=NASA Researchers: DNA Building Blocks Can Be Made in Space |url=http://www.nasa.gov/topics/solarsystem/features/dna-meteorites.html |publisher=[[NASA]] |date=8 August 2011 |access-date=2011-08-10 }}</ref><ref name="DNA">{{cite web |author=ScienceDaily Staff |title=DNA Building Blocks Can Be Made in Space, NASA Evidence Suggests |url=https://www.sciencedaily.com/releases/2011/08/110808220659.htm |date=9 August 2011 |website=[[ScienceDaily]] |access-date=2011-08-09}}</ref>