Paraxanthine

Paraxanthine

IUPAC name 1,7-dimethyl-3H-purine-2,6-dione
Other names paraxanthine, 1 ,7-Dimethylxanthine
Identifiers
CAS number	611-59-6^N
PubChem	4687
ChemSpider	4525^Y
UNII	Q3565Y41V7^Y
ChEBI	CHEBI:25858^Y
ChEMBL	CHEMBL1158^Y
Jmol-3D images	Image 1
SMILES O=C2Nc1ncn(c1C(=O)N2C)C
InChI InChI=1S/C7H8N4O2/c1-10-3-8-5-4(10)6(12)11(2)7(13)9-5/h3H,1-2H3,(H,9,13)^Y Key: QUNWUDVFRNGTCO-UHFFFAOYSA-N^Y InChI=1/C7H8N4O2/c1-10-3-8-5-4(10)6(12)11(2)7(13)9-5/h3H,1-2H3,(H,9,13) Key: QUNWUDVFRNGTCO-UHFFFAOYAS
Properties
Molecular formula	C₇H₈N₄O₂
Molar mass	180.16 g/mol
Melting point	351-352 °C
N (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Paraxanthine, or 1,7-dimethylxanthine, is a dimethyl derivative of xanthine, structurally related to caffeine. Like caffeine, paraxanthine is a psychoactive central nervous system (CNS) stimulant. It possesses a potency roughly equal to that of caffeine and is likely involved in the mediation of the effects of caffeine itself.

1 Production and metabolism
2 Physiological effects
3 Toxicity
4 References

Production and metabolism

Paraxanthine is not produced by plants and is only observed in nature as a metabolite of caffeine in animals. After intake, roughly 84% of caffeine is demethylated at the 3-position to yield paraxanthine, making it the chief metabolite of caffeine in the body.^[1]

Certain proposed synthetic pathways of caffeine make use of paraxanthine as a bypass intermediate. However, its absence in plant alkaloid assays implies that these are infrequently, if ever, directly produced by plants.

Physiological effects

Paraxanthine has a number of physiological effects on animals:

Paraxanthine is a competitive nonselective phosphodiesterase inhibitor ^[2] which raises intracellular cAMP, activates PKA, inhibits TNF-alpha ^[3]^[4] and leukotriene ^[5] synthesis, and reduces inflammation and innate immunity ^[5]
Paraxanthine is a nonselective adenosine receptor antagonist ^[6] which raises plasma epinephrine and diastolic blood pressure.
Paraxanthine is responsible for the lipolytic properties of caffeine, and its presence in the blood causes an increase in serum free fatty acid concentration.
Paraxanthine, unlike caffeine, acts as an enzymatic effector of Na⁺/K⁺ ATPase. As a result, it is responsible for increased transport of potassium ions into skeletal muscle tissue. Similarly, the compound also stimulates increases in calcium ion concentration in muscle.

Toxicity

Paraxanthine is believed to exhibit a lower toxicity than caffeine.^[7] While blood levels commensurate with average intake appear to be fairly innocuous, high blood concentrations of paraxanthine have been linked to miscarriage in pregnant mothers.^[8]

References

^ Guerreiro S, Toulorge D, Hirsch E, Marien M, Sokoloff P, Michel PP (October 2008). "Paraxanthine, the primary metabolite of caffeine, provides protection against dopaminergic cell death via stimulation of ryanodine receptor channels". Mol. Pharmacol. 74 (4): 980–9. doi:10.1124/mol.108.048207. PMID 18621927. http://molpharm.aspetjournals.org/cgi/pmidlookup?view=long&pmid=18621927.
^ Essayan DM. (2001). "Cyclic nucleotide phosphodiesterases.". J Allergy Clin Immunol. 108 (5): 671–80. doi:10.1067/mai.2001.119555. PMID 11692087.
^ Deree J, Martins JO, Melbostad H, Loomis WH, Coimbra R. (2008). "Insights into the Regulation of TNF-α Production in Human Mononuclear Cells: The Effects of Non-Specific Phosphodiesterase Inhibition". Clinics (Sao Paulo). 63 (3): 321–8. doi:10.1590/S1807-59322008000300006. PMC 2664230. PMID 18568240. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2664230.
^ Marques LJ, Zheng L, Poulakis N, Guzman J, Costabel U (February 1999). "Pentoxifylline inhibits TNF-alpha production from human alveolar macrophages". Am. J. Respir. Crit. Care Med. 159 (2): 508–11. PMID 9927365. http://ajrccm.atsjournals.org/cgi/pmidlookup?view=long&pmid=9927365.
^ ^a ^b Peters-Golden M, Canetti C, Mancuso P, Coffey MJ. (2005). "Leukotrienes: underappreciated mediators of innate immune responses". J Immunol. 174 (2): 589–94. PMID 15634873. http://www.jimmunol.org/cgi/content/full/174/2/589.
^ Daly JW, Jacobson KA, Ukena D. (1987). "Adenosine receptors: development of selective agonists and antagonists". Prog Clin Biol Res. 230 (1): 41–63. PMID 3588607.
^ Neal L. Benowitz, Peyton Jacob, Haim Mayan and Charles Denaro (1995). "Sympathomimetic effects of paraxanthine and caffeine in humans". Clinical Pharmacology & Therapeutics 58 (58): 684–691. doi:10.1016/0009-9236(95)90025-X. http://www.nature.com/clpt/journal/v58/n6/abs/clpt1995184a.html.
^ Mark A. Klebanoff, M.D., M.P.H., Richard J. Levine, M.D., M.P.H., Rebecca DerSimonian, Sc.D., John D. Clemens, M.D., and Diana G. Wilkins, Ph.D. (1999). "Maternal Serum Paraxanthine, a Caffeine Metabolite, and the Risk of Spontaneous Abortion". New England Journal of Medicine 341 (22): 1639–1644. doi:10.1056/NEJM199911253412202. PMID 10572151. http://content.nejm.org/cgi/content/full/341/22/1639.

Stimulants (N06B)

Adamantanes	Adaphenoxate • Adapromine • Amantadine • Bromantane • Chlodantane • Gludantane • Memantine • Midantane

Adenosine antagonists	8-Chlorotheophylline • 8-Cyclopentyltheophylline • 8-Phenyltheophylline • Aminophylline • Caffeine • CGS-15943 • Dimethazan • Paraxanthine • SCH-58261 • Theobromine • Theophylline

Alkylamines	Cyclopentamine • Cypenamine • Cyprodenate • Heptaminol • Isometheptene • Methylhexaneamine • Octodrine • Propylhexedrine • Tuaminoheptane

Arylcyclohexylamines	Benocyclidine • Dieticyclidine • Esketamine • Eticyclidine • Gacyclidine • Ketamine • Phencyclamine • Phencyclidine • Rolicyclidine • Tenocyclidine • Tiletamine

Benzazepines	6-Br-APB • SKF-77434 • SKF-81297 • SKF-82958

Cholinergics	A-84543 • A-366,833 • ABT-202 • ABT-418 • AR-R17779 • Altinicline • Anabasine • Arecoline • Cotinine • Cytisine • Dianicline • Epibatidine • Epiboxidine • GTS-21 • Ispronicline • Nicotine • PHA-543,613 • PNU-120,596 • PNU-282,987 • Pozanicline • Rivanicline • Sazetidine A • SIB-1553A • SSR-180,711 • TC-1698 • TC-1827 • TC-2216 • TC-5619 • Tebanicline • UB-165 • Varenicline • WAY-317,538

Convulsants	Anatoxin-a • Bicuculline • DMCM • Flurothyl • Gabazine • Pentetrazol • Picrotoxin • Strychnine • Thujone

Eugeroics	Adrafinil • Armodafinil • CRL-40941 • Modafinil

Oxazolines	4-Methylaminorex • Aminorex • Clominorex • Cyclazodone • Fenozolone • Fluminorex • Pemoline • Thozalinone

Phenethylamines	1-(4-Methylphenyl)-2-aminobutane • 1-Phenyl-2-(piperidin-1-yl)pentan-3-one • 1-Methylamino-1-(3,4-methylenedioxyphenyl)propane • 2-Fluoroamphetamine • 2-Fluoromethamphetamine • 2-OH-PEA • 2-Phenyl-3-aminobutane • 2-Phenyl-3-methylaminobutane • 2,3-MDA • 3-Fluoroamphetamine • 3-Fluoroethamphetamine • 3-Fluoromethcathinone • 3-Methoxyamphetamine • 3-Methylamphetamine • 3,4-DMMC • 4-BMC • 4-Ethylamphetamine • 4-FA • 4-FMA • 4-MA • 4-MMA • 4-MTA • 6-FNE • Alfetamine • α-Ethylphenethylamine • Amfecloral • Amfepentorex • Amfepramone • Amidephrine • Amphetamine (Dextroamphetamine, Levoamphetamine) • Amphetaminil • Arbutamine • β-Methylphenethylamine • β-Phenylmethamphetamine • Benfluorex • Benzedrone • Benzphetamine • BDB (J) • BOH (Hydroxy-J) • BPAP • Buphedrone • Bupropion (Amfebutamone) • Butylone • Cathine • Cathinone • Chlorphentermine • Cinnamedrine • Clenbuterol • Clobenzorex • Cloforex • Clortermine • D-Deprenyl • Denopamine • Dimethoxyamphetamine • Dimethylamphetamine • Dimethylcathinone (Dimethylpropion, Metamfepramone) • Dobutamine • DOPA (Dextrodopa, Levodopa) • Dopamine • Dopexamine • Droxidopa • EBDB (Ethyl-J) • Ephedrine • Epinephrine (Adrenaline) • Epinine (Deoxyepinephrine) • Etafedrine • Ethcathinone (Ethylpropion) • Ethylamphetamine (Etilamfetamine) • Ethylnorepinephrine (Butanefrine) • Ethylone • Etilefrine • Famprofazone • Fenbutrazate • Fencamine • Fenethylline • Fenfluramine (Dexfenfluramine) • Fenmetramide • Fenproporex • Flephedrone • Fludorex • Furfenorex • Gepefrine • HMMA • Hordenine • Ibopamine • IMP • Indanylamphetamine • Isoetarine • Isoethcathinone • Isoprenaline (Isoproterenol) • L-Deprenyl (Selegiline) • Lefetamine • Lisdexamfetamine • Lophophine (Homomyristicylamine) • Manifaxine • MBDB (Methyl-J; "Eden") • MDA (Tenamfetamine) • MDBU • MDEA ("Eve") • MDMA ("Ecstasy", "Adam") • MDMPEA (Homarylamine) • MDOH • MDPR • MDPEA (Homopiperonylamine) • Mefenorex • Mephedrone • Mephentermine • Metanephrine • Metaraminol • Methamphetamine (Desoxyephedrine, Methedrine; Dextromethamphetamine, Levomethamphetamine) • Methoxamine • Methoxyphenamine • MMA • Methcathinone (Methylpropion) • Methedrone • Methoxyphenamine • Methylone • MMDA • MMDMA • MMMA • Morazone • N-Benzyl-1-phenethylamine • N,N-Dimethylphenethylamine • Naphthylamphetamine • Nisoxetine • Norepinephrine (Noradrenaline) • Norfenefrine • Norfenfluramine • Normetanephrine • Octopamine • Orciprenaline • Ortetamine • Oxilofrine • Paredrine (Norpholedrine, Oxamphetamine, Mycadrine) • PBA • PCA • PHA • Pargyline • Pentorex (Phenpentermine) • Pentylone • Phenatine • Phendimetrazine • Phenmetrazine • Phenpromethamine • Phentermine • Phenylalanine • Phenylephrine (Neosynephrine) • Phenylpropanolamine • Pholedrine • PIA • PMA • PMEA • PMMA • PPAP • Prenylamine • Propylamphetamine • Pseudoephedrine • Radafaxine • Ropinirole • Salbutamol (Albuterol; Levosalbutamol) • Sibutramine • Synephrine (Oxedrine) • Theodrenaline • Tiflorex (Flutiorex) • Tranylcypromine • Tyramine • Tyrosine • Xamoterol • Xylopropamine • Zylofuramine

Piperazines	2C-B-BZP • BZP • CM156 • DBL-583 • GBR-12783 • GBR-12935 • GBR-13069 • GBR-13098 • GBR-13119 • MeOPP • MBZP • Vanoxerine

Piperidines	1-Benzyl-4-(2-(diphenylmethoxy)ethyl)piperidine • 1-(3,4-Dichlorophenyl)-1-(piperidin-2-yl)butane • 2-Benzylpiperidine • 2-Methyl-3-phenylpiperidine • 3,4-Dichloromethylphenidate • 4-Benzylpiperidine • 4-Methylmethylphenidate • Desoxypipradrol • Difemetorex • Diphenylpyraline • Ethylphenidate • Methylnaphthidate • Methylphenidate (Dexmethylphenidate) • N-Methyl-3β-propyl-4β-(4-chlorophenyl)piperidine • Nocaine • Phacetoperane • Pipradrol • SCH-5472

Pyrrolidines	2-Diphenylmethylpyrrolidine • α-PPP • α-PBP • α-PVP • Diphenylprolinol • MDPPP • MDPBP • MDPV • MPBP • MPHP • MPPP • MOPPP • Naphyrone • PEP • Prolintane • Pyrovalerone

Tropanes	3-CPMT • 3'-Chloro-3α-(diphenylmethoxy)tropane • 3-Pseudotropyl-4-fluorobenzoate • 4'-Fluorococaine • AHN-1055 • Altropane (IACFT) • Brasofensine • CFT (WIN 35,428) • β-CIT (RTI-55) • Cocaethylene • Cocaine • Dichloropane (RTI-111) • Difluoropine • FE-β-CPPIT • FP-β-CPPIT • Ioflupane (¹²³I) • Norcocaine • PIT • PTT • RTI-31 • RTI-32 • RTI-51 • RTI-105 • RTI-112 • RTI-113 • RTI-117 • RTI-120 • RTI-121 (IPCIT) • RTI-126 • RTI-150 • RTI-154 • RTI-171 • RTI-177 • RTI-183 • RTI-193 • RTI-194 • RTI-199 • RTI-202 • RTI-204 • RTI-229 • RTI-241 • RTI-336 • RTI-354 • RTI-371 • RTI-386 • Salicylmethylecgonine • Tesofensine • Troparil (β-CPT, WIN 35,065-2) • Tropoxane • WF-23 • WF-33 • WF-60

Others	1-(Thiophen-2-yl)-2-aminopropane • 2-Amino-1,2-dihydronaphthalene • 2-Aminoindane • 2-Aminotetralin • 2-MDP • 2-Phenylcyclohexylamine • 2-Phenyl-3,6-dimethylmorpholine • 3-Benzhydrylmorpholine • 3,3-Diphenylcyclobutanamine • 5-(2-Aminopropyl)indole • 5-Iodo-2-aminoindane • AL-1095 • Amfonelic acid • Amineptine • Amiphenazole • Atipamezole • Atomoxetine (Tomoxetine) • Bemegride • Benzydamine • BTQ • BTS 74,398 • Carphedon • Ciclazindol • Cilobamine • Clofenciclan • Cropropamide • Crotetamide • Cypenamine • D-161 • Diclofensine • Dimethocaine • Efaroxan • Etamivan • EXP-561 • Fencamfamine • Fenpentadiol • Feprosidnine • G-130 • Gamfexine • Gilutensin • GSK1360707F • GYKI-52895 • Hexacyclonate • Idazoxan • Indanorex • Indatraline • JNJ-7925476 • JZ-IV-10 • Lazabemide • Leptacline • Levopropylhexedrine • Lomevactone • LR-5182 • Mazindol • Meclofenoxate • Medifoxamine • Mefexamide • Mesocarb • Methastyridone • Methiopropamine • N-Methyl-3-phenylnorbornan-2-amine • Nefopam • Nikethamide • Nomifensine • O-2172 • Oxaprotiline • Phthalimidopropiophenone • PNU-99,194 • Propylhexedrine • PRC200-SS • Rasagiline • Rauwolscine • Rubidium chloride • Setazindol • Tametraline • Tandamine • Trazium • UH-232 • Yohimbine

See also Sympathomimetic amines

Adenosinergics

Receptor ligands

Agonists	2-(1-Hexynyl)-N-methyladenosine • 2-Cl-IB-MECA • 2'-MeCCPA • 5'-N-ethylcarboxamidoadenosine • ATL-146e • BAY 60–6583 • CCPA • CGS-21680 • CP-532,903 • GR 79236 • LUF-5835 • LUF-5845 • N6-Cyclopentyladenosine • Regadenoson • SDZ WAG 994 • UK-432,097

Antagonists	8-Phenyl-1,3-dipropylxanthine • Acefylline • Aminophylline • Bamifylline • Caffeine • CGS-15943 • 8-Chlorotheophylline • CPX • CVT-6883 • Dimethazan • DPCPX • Fenethylline • Istradefylline • KF-26777 • MRE3008F20 • MRS-1220 • MRS-1334 • MRS-1706 • MRS-1754 • MRS-3777 • Paraxanthine • Pentoxifylline • Preladenant • Propentofylline • PSB-10 • PSB-11 • PSB 36 • PSB-603 • PSB-788 • PSB-1115 • Rolofylline • SCH-442,416 • SCH-58261 • Theobromine • Theophylline • VUF-5574 • ZM-241,385

Reuptake inhibitors

Plasmalemmal

ENT inhibitors	Dilazep • Dipyridamole • Hexobendine • Pentoxifylline • Propentofylline

Vesicular

VNT inhibitors

Paraxanthine

Contents

Production and metabolism

Physiological effects

Toxicity

References