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Wikipedia

Purine

February 16, 2024

Purine is a heterocyclic aromatic organic compound that consists of two rings (pyrimidine and imidazole) fused together. It is water-soluble. Purine also gives its name to the wider class of molecules, purines, which include substituted purines and their tautomers. They are the most widely occurring nitrogen-containing heterocycles in nature.[1]

Purine
Names
IUPAC name
9H-purine
Identifiers
  • 120-73-0 Y
3D model (JSmol)
  • Interactive image
ChEBI
  • CHEBI:17257 Y
ChEMBL
  • ChEMBL302239 Y
ChemSpider
  • 1015 Y
ECHA InfoCard 100.004.020
KEGG
  • C15587 Y
MeSH Purine
  • 1044
UNII
  • W60KTZ3IZY Y
  • DTXSID5074470
  • InChI=1S/C5H4N4/c1-4-5(8-2-6-1)9-3-7-4/h1-3H,(H,6,7,8,9) Y
    Key: KDCGOANMDULRCW-UHFFFAOYSA-N Y
  • InChI=1/C5H4N4/c1-4-5(8-2-6-1)9-3-7-4/h1-3H,(H,6,7,8,9)
    Key: KDCGOANMDULRCW-UHFFFAOYAO
  • c1c2c(nc[nH]2)ncn1
Properties
C5H4N4
Molar mass 120.115 g·mol−1
Melting point 214 °C (417 °F; 487 K)
500 g/L (RT)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y verify (what is YN ?)

Dietary sources edit

Purines are found in high concentration in meat and meat products, especially internal organs such as liver and kidney. In general, plant-based diets are low in purines.[2] High-purine plants and algae include some legumes (lentils, soybeans, and black-eyed peas) and spirulina. Examples of high-purine sources include: sweetbreads, anchovies, sardines, liver, beef kidneys, brains, meat extracts (e.g., Oxo, Bovril), herring, mackerel, scallops, game meats, yeast (beer, yeast extract, nutritional yeast) and gravy.[3]

A moderate amount of purine is also contained in red meat, beef, pork, poultry, fish and seafood, asparagus, cauliflower, spinach, mushrooms, green peas, lentils, dried peas, beans, oatmeal, wheat bran, wheat germ, and haws.[4]

Biochemistry edit

Purines and pyrimidines make up the two groups of nitrogenous bases, including the two groups of nucleotide bases. The purine bases are guanine (G) and adenine (A) which form corresponding nucleosides-deoxyribonucleosides (deoxyguanosine and deoxyadenosine) with deoxyribose moiety and ribonucleosides (guanosine, adenosine) with ribose moiety. These nucleosides with phosphoric acid form corresponding nucleotides (deoxyguanylate, deoxyadenylate and guanylate, adenylate) which are the building blocks of DNA and RNA, respectively. Purine bases also play an essential role in many metabolic and signalling processes within the compounds guanosine monophosphate (GMP) and adenosine monophosphate (AMP).

In order to perform these essential cellular processes, both purines and pyrimidines are needed by the cell, and in similar quantities. Both purine and pyrimidine are self-inhibiting and activating. When purines are formed, they inhibit the enzymes required for more purine formation. This self-inhibition occurs as they also activate the enzymes needed for pyrimidine formation. Pyrimidine simultaneously self-inhibits and activates purine in a similar manner. Because of this, there is nearly an equal amount of both substances in the cell at all times.[5]

Properties edit

Purine is both a very weak acid (pKa 8.93) and an even weaker base (pKa 2.39).[6] If dissolved in pure water, the pH is halfway between these two pKa values.

Purine is aromatic, having four tautomers each with a hydrogen bonded to a different one of the four nitrogen atoms. These are identified as 1-H, 3-H, 7-H, and 9-H (see image of numbered ring). The common crystalline form favours the 7-H tautomer, while in polar solvents both the 9-H and 7-H tautomers predominate.[7] Substituents to the rings and interactions with other molecules can shift the equilibrium of these tautomers.[8]

Notable purines edit

There are many naturally occurring purines. They include the nucleobases adenine (2) and guanine (3). In DNA, these bases form hydrogen bonds with their complementary pyrimidines, thymine and cytosine, respectively. This is called complementary base pairing. In RNA, the complement of adenine is uracil instead of thymine.

Other notable purines are hypoxanthine, xanthine, theophylline, theobromine, caffeine, uric acid and isoguanine.  [contradictory]

Functions edit

 
The main purine-derived nucleobases.

Aside from the crucial roles of purines (adenine and guanine) in DNA and RNA, purines are also significant components in a number of other important biomolecules, such as ATP, GTP, cyclic AMP, NADH, and coenzyme A. Purine (1) itself, has not been found in nature, but it can be produced by organic synthesis.

They may also function directly as neurotransmitters, acting upon purinergic receptors. Adenosine activates adenosine receptors.

History edit

The word purine (pure urine)[9] was coined by the German chemist Emil Fischer in 1884.[10][11] He synthesized it for the first time in 1898.[11] The starting material for the reaction sequence was uric acid (8), which had been isolated from kidney stones by Carl Wilhelm Scheele in 1776.[12] Uric acid (8) was reacted with PCl5 to give 2,6,8-trichloropurine (10), which was converted with HI and PH4I to give 2,6-diiodopurine (11). The product was reduced to purine (1) using zinc dust.  

Metabolism edit

Main article: Purine metabolism

Many organisms have metabolic pathways to synthesize and break down purines.

Purines are biologically synthesized as nucleosides (bases attached to ribose).

Accumulation of modified purine nucleotides is defective to various cellular processes, especially those involving DNA and RNA. To be viable, organisms possess a number of deoxypurine phosphohydrolases, which hydrolyze these purine derivatives removing them from the active NTP and dNTP pools. Deamination of purine bases can result in accumulation of such nucleotides as ITP, dITP, XTP and dXTP.[13]

Defects in enzymes that control purine production and breakdown can severely alter a cell's DNA sequences, which may explain why people who carry certain genetic variants of purine metabolic enzymes have a higher risk for some types of cancer.

Purine biosynthesis in the three domains of life edit

Organisms in all three domains of life, eukaryotes, bacteria and archaea, are able to carry out de novo biosynthesis of purines. This ability reflects the essentiality of purines for life. The biochemical pathway of synthesis is very similar in eukaryotes and bacterial species, but is more variable among archaeal species.[14] A nearly complete, or complete, set of genes required for purine biosynthesis was determined to be present in 58 of the 65 archaeal species studied.[14] However, also identified were seven archaeal species with entirely, or nearly entirely, absent purine encoding genes. Apparently the archaeal species unable to synthesize purines are able to acquire exogenous purines for growth.,[14] and are thus analogous to purine mutants of eukaryotes, e.g. purine mutants of the Ascomycete fungus Neurospora crassa,[15] that also require exogenous purines for growth.

Relationship with gout edit

See also: Gout § Cause

Higher levels of meat and seafood consumption are associated with an increased risk of gout, whereas a higher level of consumption of dairy products is associated with a decreased risk. Moderate intake of purine-rich vegetables or protein is not associated with an increased risk of gout.[16] Similar results have been found with the risk of hyperuricemia.

Laboratory synthesis edit

In addition to in vivo synthesis of purines in purine metabolism, purine can also be synthesized artificially.

Purine (1) is obtained in good yield when formamide is heated in an open vessel at 170 °C for 28 hours.[17]

 

This remarkable reaction and others like it have been discussed in the context of the origin of life.[18]

Patented August 20, 1968, the current recognized method of industrial-scale production of adenine is a modified form of the formamide method. This method heats up formamide under 120 degree Celsius conditions within a sealed flask for 5 hours to form adenine. The reaction is heavily increased  in quantity by using a phosphorus oxychloride (phosphoryl chloride) or phosphorus pentachloride as an acid catalyst and sunlight or ultraviolet conditions. After the 5 hours have passed and the formamide-phosphorus oxychloride-adenine solution cools down, water is put into the flask containing the formamide and now-formed adenine. The water-formamide-adenine solution is then poured through a filtering column of activated charcoal. The water and formamide molecules, being small molecules, will pass through the charcoal and into the waste flask; the large adenine molecules, however, will attach or “adsorb” to the charcoal due to the van der waals forces that interact between the adenine and the carbon in the charcoal. Because charcoal has a large surface area, it's able to capture the majority of molecules that pass a certain size (greater than water and formamide) through it. To extract the adenine from the charcoal-adsorbed adenine, ammonia gas dissolved in water (aqua ammonia) is poured onto the activated charcoal-adenine structure to liberate the adenine into the ammonia-water solution. The solution containing water, ammonia, and adenine is then left to air dry, with the adenine losing solubility due to the loss of ammonia gas that previously made the solution basic and capable of dissolving adenine, thus causing it to crystallize into a pure white powder that can be stored.[19]

Oro and Kamat (1961) and Orgel co-workers (1966, 1967) have shown that four molecules of HCN tetramerize to form diaminomaleodinitrile (12), which can be converted into almost all naturally occurring purines.[20][21][22][23][24] For example, five molecules of HCN condense in an exothermic reaction to make adenine, especially in the presence of ammonia.  

The Traube purine synthesis (1900) is a classic reaction (named after Wilhelm Traube) between an amine-substituted pyrimidine and formic acid.[25] 

Prebiotic synthesis of purine ribonucleosides edit

In order to understand how life arose, knowledge is required of the chemical pathways that permit formation of the key building blocks of life under plausible prebiotic conditions. Nam et al. (2018)[26] demonstrated the direct condensation of purine and pyrimidine nucleobases with ribose to give ribonucleosides in aqueous microdroplets, a key step leading to RNA formation. Also, a plausible prebiotic process for synthesizing purine ribonucleosides was presented by Becker et al. (2016).[27]

See also edit

References edit

  1. ^ Rosemeyer H (March 2004). "The chemodiversity of purine as a constituent of natural products". Chemistry & Biodiversity. 1 (3): 361–401. doi:10.1002/cbdv.200490033. PMID 17191854. S2CID 12416667.
  2. ^ "Gout: List of Foods High and Low in Purine Content". Dietaryfiberfood.com. 2016-04-08. from the original on 2011-11-12. Retrieved 2016-07-16.
  3. ^ Kaneko K, Aoyagi Y, Fukuuchi T, Inazawa K, Yamaoka N (2014). "Total purine and purine base content of common foodstuffs for facilitating nutritional therapy for gout and hyperuricemia". Biological & Pharmaceutical Bulletin. 37 (5): 709–721. doi:10.1248/bpb.b13-00967. PMID 24553148.
  4. ^ "Gout Diet: What Foods To Avoid". Healthcastle.com. from the original on 2017-08-14. Retrieved 2016-07-16.
  5. ^ Guyton AC (2006). Textbook of Medical Physiology. Philadelphia, PA: Elsevier. p. 37. ISBN 978-0-7216-0240-0.
  6. ^ Seela F, et al. (2014). Schaumann E (ed.). Houben-Weyl Methods of Organic Chemistry. Vol. E 9b/2 (4th Supplement: Hetarenes III (Six-Membered Rings and Larger Hetero-Rings with Maximum Unsaturation) - Part 2b ed.). Thieme. p. 310. ISBN 9783131815040. from the original on 2022-02-17. Retrieved 2020-05-15.
  7. ^ Raczyńska ED, Gal JF, Maria PC, Kamińska B, Igielska M, Kurpiewski J, Juras W (April 2020). "Purine tautomeric preferences and bond-length alternation in relation with protonation-deprotonation and alkali metal cationization". Journal of Molecular Modeling. 26 (5): 93. doi:10.1007/s00894-020-4343-6. PMC 7256107. PMID 32248379.
  8. ^ Stasyuk OA, Szatyłowicz H, Krygowski TM (April 2012). "Effect of the H-bonding on aromaticity of purine tautomers". The Journal of Organic Chemistry. 77 (8): 4035–4045. doi:10.1021/jo300406r. PMID 22448684.
  9. ^ McGuigan H (1921). An Introduction To Chemical Pharmacology. P. Blakiston's Sons & Co. p. 283. from the original on April 16, 2020. Retrieved July 18, 2012.
  10. ^ Fischer E (1884). "Ueber die Harnsäure. I." [On uric acid. I.] (PDF). Berichte der Deutschen Chemischen Gesellschaft. 17: 328–338. doi:10.1002/cber.18840170196. Retrieved 2016-04-20.  
    From p. 329 2022-02-17 at the Wayback Machine: "Um eine rationelle Nomenklatur der so entstehenden zahlreichen Substanzen zu ermöglichen, betrachte ich dieselben als Abkömmlinge der noch unbekannten Wasserstoffverbindung CH3.C5N4H3 and nenne die letztere Methylpurin." (In order to make possible a rational nomenclature for the numerous existing substances, I regarded them as derivatives of a still unknown hydrogen compound, CH3.C5N4H3, and call the latter "methylpurine".)
  11. ^ a b Fischer E (1898). "Ueber das Purin und seine Methylderivate" [On purine and its methyl derivatives] (PDF). Berichte der Deutschen Chemischen Gesellschaft. 31 (3): 2550–2574. doi:10.1002/cber.18980310304. Retrieved 2016-04-20.  
    From p. 2550 2020-10-18 at the Wayback Machine: "…hielt ich es für zweckmäßig, alle diese Produkte ebenso wie die Harnsäure als Derivate der sauerstofffreien Verbindung C5H4N4 zu betrachten, und wählte für diese den Namen Purin, welcher aus den Wörtern purum und uricum kombiniert war." (…I regarded it as expedient to consider all of these products, just like uric acid, as derivatives of the oxygen-free compound C5H4N4, and chose for them the name "purine", which was formed from the [Latin] words purum and uricum.)
  12. ^ Scheele CW (1776). "Examen chemicum calculi urinari" [A chemical examination of kidney stones]. Opuscula. 2: 73.
  13. ^ Davies O, Mendes P, Smallbone K, Malys N (April 2012). "Characterisation of multiple substrate-specific (d)ITP/(d)XTPase and modelling of deaminated purine nucleotide metabolism". BMB Reports. 45 (4): 259–264. doi:10.5483/BMBRep.2012.45.4.259. PMID 22531138.
  14. ^ a b c Brown, Anne M.; Hoopes, Samantha L.; White, Robert H.; Sarisky, Catherine A. (2011). "Purine biosynthesis in archaea: Variations on a theme". Biology Direct. 6: 63. doi:10.1186/1745-6150-6-63. PMC 3261824. PMID 22168471.
  15. ^ Bernstein, H. (1961). "Imidazole Compounds Accumulated by Purine Mutants of Neurospora crassa". Journal of General Microbiology. 25: 41–46. doi:10.1099/00221287-25-1-41.
  16. ^ Choi HK, Atkinson K, Karlson EW, Willett W, Curhan G (March 2004). "Purine-rich foods, dairy and protein intake, and the risk of gout in men". The New England Journal of Medicine. 350 (11): 1093–1103. doi:10.1056/NEJMoa035700. PMID 15014182.
  17. ^ Yamada H, Okamoto T (1972). "A One-step Synthesis of Purine Ring from Formamide". Chemical & Pharmaceutical Bulletin. 20 (3): 623. doi:10.1248/cpb.20.623. Archived from the original on 2016-05-16.
  18. ^ Saladino R, Crestini C, Ciciriello F, Costanzo G, Di Mauro E (December 2006). "About a formamide-based origin of informational polymers: syntheses of nucleobases and favourable thermodynamic niches for early polymers". Origins of Life and Evolution of the Biosphere. 36 (5–6): 523–531. Bibcode:2006OLEB...36..523S. doi:10.1007/s11084-006-9053-2. PMID 17136429. S2CID 36278915.
  19. ^ [1], "Process for preparing adenine", issued 1966-11-10  2021-05-26 at the Wayback Machine
  20. ^ Sanchez RA, Ferris JP, Orgel LE (December 1967). "Studies in prebiotic synthesis. II. Synthesis of purine precursors and amino acids from aqueous hydrogen cyanide". Journal of Molecular Biology. 30 (2): 223–253. doi:10.1016/S0022-2836(67)80037-8. PMID 4297187.
  21. ^ Ferris JP, Orgel LE (March 1966). "An Unusual Photochemical Rearrangement in the Synthesis of Adenine from Hydrogen Cyanide". Journal of the American Chemical Society. 88 (5): 1074. doi:10.1021/ja00957a050.
  22. ^ Ferris JP, Kuder JE, Catalano AW (November 1969). "Photochemical reactions and the chemical evolution of purines and nicotinamide derivatives". Science. 166 (3906): 765–766. Bibcode:1969Sci...166..765F. doi:10.1126/science.166.3906.765. PMID 4241847. S2CID 695243.
  23. ^ Oro J, Kamat SS (April 1961). "Amino-acid synthesis from hydrogen cyanide under possible primitive earth conditions". Nature. 190 (4774): 442–443. Bibcode:1961Natur.190..442O. doi:10.1038/190442a0. PMID 13731262. S2CID 4219284.
  24. ^ Bauer W (1985). Houben-Weyl Methods of Organic Chemistry Vol. E 5, 4th Edition Supplement. Thieme Georg Verlag. p. 1547. ISBN 9783131811547.
  25. ^ Hassner A, Stumer C (2002). Organic Syntheses Based on Name Reactions (2nd ed.). Elsevier. ISBN 0-08-043259-X.
  26. ^ Nam I, Nam HG, Zare RN. (2018, Jan 2). Abiotic synthesis of purine and pyrimidine ribonucleosides in aqueous microdroplets. Proc Natl Acad Sci USA. 115(1):36–40. doi: 10.1073/pnas.1718559115. Epub 2017 Dec 18. PMID 29255025; PMCID: PMC5776833
  27. ^ Becker S, Thoma I, Deutsch A, Gehrke T, Mayer P, Zipse H, Carell T. (2016, May 13). A high-yielding, strictly regioselective prebiotic purine nucleoside formation pathway. Science. 352(6287):833–6. doi: 10.1126/science.aad2808. PMID 27174989.

External links edit

  • Purine Content in Food

February 16, 2024
purine, heterocyclic, aromatic, organic, compound, that, consists, rings, pyrimidine, imidazole, fused, together, water, soluble, also, gives, name, wider, class, molecules, purines, which, include, substituted, purines, their, tautomers, they, most, widely, o. Purine is a heterocyclic aromatic organic compound that consists of two rings pyrimidine and imidazole fused together It is water soluble Purine also gives its name to the wider class of molecules purines which include substituted purines and their tautomers They are the most widely occurring nitrogen containing heterocycles in nature 1 Purine NamesIUPAC name 9H purineIdentifiersCAS Number 120 73 0 Y3D model JSmol Interactive imageChEBI CHEBI 17257 YChEMBL ChEMBL302239 YChemSpider 1015 YECHA InfoCard 100 004 020KEGG C15587 YMeSH PurinePubChem CID 1044UNII W60KTZ3IZY YCompTox Dashboard EPA DTXSID5074470InChI InChI 1S C5H4N4 c1 4 5 8 2 6 1 9 3 7 4 h1 3H H 6 7 8 9 YKey KDCGOANMDULRCW UHFFFAOYSA N YInChI 1 C5H4N4 c1 4 5 8 2 6 1 9 3 7 4 h1 3H H 6 7 8 9 Key KDCGOANMDULRCW UHFFFAOYAOSMILES c1c2c nc nH 2 ncn1PropertiesChemical formula C 5H 4N 4Molar mass 120 115 g mol 1Melting point 214 C 417 F 487 K Solubility in water 500 g L RT Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa Y verify what is Y N Infobox references Contents 1 Dietary sources 2 Biochemistry 3 Properties 4 Notable purines 5 Functions 6 History 7 Metabolism 7 1 Purine biosynthesis in the three domains of life 7 2 Relationship with gout 8 Laboratory synthesis 9 Prebiotic synthesis of purine ribonucleosides 10 See also 11 References 12 External linksDietary sources editPurines are found in high concentration in meat and meat products especially internal organs such as liver and kidney In general plant based diets are low in purines 2 High purine plants and algae include some legumes lentils soybeans and black eyed peas and spirulina Examples of high purine sources include sweetbreads anchovies sardines liver beef kidneys brains meat extracts e g Oxo Bovril herring mackerel scallops game meats yeast beer yeast extract nutritional yeast and gravy 3 A moderate amount of purine is also contained in red meat beef pork poultry fish and seafood asparagus cauliflower spinach mushrooms green peas lentils dried peas beans oatmeal wheat bran wheat germ and haws 4 Biochemistry editPurines and pyrimidines make up the two groups of nitrogenous bases including the two groups of nucleotide bases The purine bases are guanine G and adenine A which form corresponding nucleosides deoxyribonucleosides deoxyguanosine and deoxyadenosine with deoxyribose moiety and ribonucleosides guanosine adenosine with ribose moiety These nucleosides with phosphoric acid form corresponding nucleotides deoxyguanylate deoxyadenylate and guanylate adenylate which are the building blocks of DNA and RNA respectively Purine bases also play an essential role in many metabolic and signalling processes within the compounds guanosine monophosphate GMP and adenosine monophosphate AMP In order to perform these essential cellular processes both purines and pyrimidines are needed by the cell and in similar quantities Both purine and pyrimidine are self inhibiting and activating When purines are formed they inhibit the enzymes required for more purine formation This self inhibition occurs as they also activate the enzymes needed for pyrimidine formation Pyrimidine simultaneously self inhibits and activates purine in a similar manner Because of this there is nearly an equal amount of both substances in the cell at all times 5 Properties editPurine is both a very weak acid pKa 8 93 and an even weaker base pKa 2 39 6 If dissolved in pure water the pH is halfway between these two pKa values Purine is aromatic having four tautomers each with a hydrogen bonded to a different one of the four nitrogen atoms These are identified as 1 H 3 H 7 H and 9 H see image of numbered ring The common crystalline form favours the 7 H tautomer while in polar solvents both the 9 H and 7 H tautomers predominate 7 Substituents to the rings and interactions with other molecules can shift the equilibrium of these tautomers 8 Notable purines editThere are many naturally occurring purines They include the nucleobases adenine 2 and guanine 3 In DNA these bases form hydrogen bonds with their complementary pyrimidines thymine and cytosine respectively This is called complementary base pairing In RNA the complement of adenine is uracil instead of thymine Other notable purines are hypoxanthine xanthine theophylline theobromine caffeine uric acid and isoguanine nbsp contradictory Functions edit nbsp The main purine derived nucleobases Aside from the crucial roles of purines adenine and guanine in DNA and RNA purines are also significant components in a number of other important biomolecules such as ATP GTP cyclic AMP NADH and coenzyme A Purine 1 itself has not been found in nature but it can be produced by organic synthesis They may also function directly as neurotransmitters acting upon purinergic receptors Adenosine activates adenosine receptors History editThe word purine pure urine 9 was coined by the German chemist Emil Fischer in 1884 10 11 He synthesized it for the first time in 1898 11 The starting material for the reaction sequence was uric acid 8 which had been isolated from kidney stones by Carl Wilhelm Scheele in 1776 12 Uric acid 8 was reacted with PCl5 to give 2 6 8 trichloropurine 10 which was converted with HI and PH4I to give 2 6 diiodopurine 11 The product was reduced to purine 1 using zinc dust nbsp Metabolism editMain article Purine metabolism Many organisms have metabolic pathways to synthesize and break down purines Purines are biologically synthesized as nucleosides bases attached to ribose Accumulation of modified purine nucleotides is defective to various cellular processes especially those involving DNA and RNA To be viable organisms possess a number of deoxypurine phosphohydrolases which hydrolyze these purine derivatives removing them from the active NTP and dNTP pools Deamination of purine bases can result in accumulation of such nucleotides as ITP dITP XTP and dXTP 13 Defects in enzymes that control purine production and breakdown can severely alter a cell s DNA sequences which may explain why people who carry certain genetic variants of purine metabolic enzymes have a higher risk for some types of cancer Purine biosynthesis in the three domains of life edit Organisms in all three domains of life eukaryotes bacteria and archaea are able to carry out de novo biosynthesis of purines This ability reflects the essentiality of purines for life The biochemical pathway of synthesis is very similar in eukaryotes and bacterial species but is more variable among archaeal species 14 A nearly complete or complete set of genes required for purine biosynthesis was determined to be present in 58 of the 65 archaeal species studied 14 However also identified were seven archaeal species with entirely or nearly entirely absent purine encoding genes Apparently the archaeal species unable to synthesize purines are able to acquire exogenous purines for growth 14 and are thus analogous to purine mutants of eukaryotes e g purine mutants of the Ascomycete fungus Neurospora crassa 15 that also require exogenous purines for growth Relationship with gout edit See also Gout Cause Higher levels of meat and seafood consumption are associated with an increased risk of gout whereas a higher level of consumption of dairy products is associated with a decreased risk Moderate intake of purine rich vegetables or protein is not associated with an increased risk of gout 16 Similar results have been found with the risk of hyperuricemia Laboratory synthesis editIn addition to in vivo synthesis of purines in purine metabolism purine can also be synthesized artificially Purine 1 is obtained in good yield when formamide is heated in an open vessel at 170 C for 28 hours 17 nbsp This remarkable reaction and others like it have been discussed in the context of the origin of life 18 Patented August 20 1968 the current recognized method of industrial scale production of adenine is a modified form of the formamide method This method heats up formamide under 120 degree Celsius conditions within a sealed flask for 5 hours to form adenine The reaction is heavily increased in quantity by using a phosphorus oxychloride phosphoryl chloride or phosphorus pentachloride as an acid catalyst and sunlight or ultraviolet conditions After the 5 hours have passed and the formamide phosphorus oxychloride adenine solution cools down water is put into the flask containing the formamide and now formed adenine The water formamide adenine solution is then poured through a filtering column of activated charcoal The water and formamide molecules being small molecules will pass through the charcoal and into the waste flask the large adenine molecules however will attach or adsorb to the charcoal due to the van der waals forces that interact between the adenine and the carbon in the charcoal Because charcoal has a large surface area it s able to capture the majority of molecules that pass a certain size greater than water and formamide through it To extract the adenine from the charcoal adsorbed adenine ammonia gas dissolved in water aqua ammonia is poured onto the activated charcoal adenine structure to liberate the adenine into the ammonia water solution The solution containing water ammonia and adenine is then left to air dry with the adenine losing solubility due to the loss of ammonia gas that previously made the solution basic and capable of dissolving adenine thus causing it to crystallize into a pure white powder that can be stored 19 Oro and Kamat 1961 and Orgel co workers 1966 1967 have shown that four molecules of HCN tetramerize to form diaminomaleodinitrile 12 which can be converted into almost all naturally occurring purines 20 21 22 23 24 For example five molecules of HCN condense in an exothermic reaction to make adenine especially in the presence of ammonia nbsp The Traube purine synthesis 1900 is a classic reaction named after Wilhelm Traube between an amine substituted pyrimidine and formic acid 25 nbsp Prebiotic synthesis of purine ribonucleosides editIn order to understand how life arose knowledge is required of the chemical pathways that permit formation of the key building blocks of life under plausible prebiotic conditions Nam et al 2018 26 demonstrated the direct condensation of purine and pyrimidine nucleobases with ribose to give ribonucleosides in aqueous microdroplets a key step leading to RNA formation Also a plausible prebiotic process for synthesizing purine ribonucleosides was presented by Becker et al 2016 27 See also editPurinones Pyrimidine Simple aromatic rings Transition Transversion Gout a disorder of purine metabolism Adenine GuanineReferences edit Rosemeyer H March 2004 The chemodiversity of purine as a constituent of natural products Chemistry amp Biodiversity 1 3 361 401 doi 10 1002 cbdv 200490033 PMID 17191854 S2CID 12416667 Gout List of Foods High and Low in Purine Content Dietaryfiberfood com 2016 04 08 Archived from the original on 2011 11 12 Retrieved 2016 07 16 Kaneko K Aoyagi Y Fukuuchi T Inazawa K Yamaoka N 2014 Total purine and purine base content of common foodstuffs for facilitating nutritional therapy for gout and hyperuricemia Biological amp Pharmaceutical Bulletin 37 5 709 721 doi 10 1248 bpb b13 00967 PMID 24553148 Gout Diet What Foods To Avoid Healthcastle com Archived from the original on 2017 08 14 Retrieved 2016 07 16 Guyton AC 2006 Textbook of Medical Physiology Philadelphia PA Elsevier p 37 ISBN 978 0 7216 0240 0 Seela F et al 2014 Schaumann E ed Houben Weyl Methods of Organic Chemistry Vol E 9b 2 4th Supplement Hetarenes III Six Membered Rings and Larger Hetero Rings with Maximum Unsaturation Part 2b ed Thieme p 310 ISBN 9783131815040 Archived from the original on 2022 02 17 Retrieved 2020 05 15 Raczynska ED Gal JF Maria PC Kaminska B Igielska M Kurpiewski J Juras W April 2020 Purine tautomeric preferences and bond length alternation in relation with protonation deprotonation and alkali metal cationization Journal of Molecular Modeling 26 5 93 doi 10 1007 s00894 020 4343 6 PMC 7256107 PMID 32248379 Stasyuk OA Szatylowicz H Krygowski TM April 2012 Effect of the H bonding on aromaticity of purine tautomers The Journal of Organic Chemistry 77 8 4035 4045 doi 10 1021 jo300406r PMID 22448684 McGuigan H 1921 An Introduction To Chemical Pharmacology P Blakiston s Sons amp Co p 283 Archived from the original on April 16 2020 Retrieved July 18 2012 Fischer E 1884 Ueber die Harnsaure I On uric acid I PDF Berichte der Deutschen Chemischen Gesellschaft 17 328 338 doi 10 1002 cber 18840170196 Retrieved 2016 04 20 nbsp From p 329 Archived 2022 02 17 at the Wayback Machine Um eine rationelle Nomenklatur der so entstehenden zahlreichen Substanzen zu ermoglichen betrachte ich dieselben als Abkommlinge der noch unbekannten Wasserstoffverbindung CH3 C5N4H3 and nenne die letztere Methylpurin In order to make possible a rational nomenclature for the numerous existing substances I regarded them 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Content in Food Retrieved from https en wikipedia org w index php title Purine amp oldid 1204113612, wikipedia, wiki, book, books, library,

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