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Pyrophosphate

February 16, 2024

"Diphosphate" redirects here. It can also refer to any salt containing two phosphate groups.

In chemistry, pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P−O−P linkage. A number of pyrophosphate salts exist, such as disodium pyrophosphate (Na2H2P2O7) and tetrasodium pyrophosphate (Na4P2O7), among others. Often pyrophosphates are called diphosphates. The parent pyrophosphates are derived from partial or complete neutralization of pyrophosphoric acid. The pyrophosphate bond is also sometimes referred to as a phosphoanhydride bond, a naming convention which emphasizes the loss of water that occurs when two phosphates form a new P−O−P bond, and which mirrors the nomenclature for anhydrides of carboxylic acids. Pyrophosphates are found in ATP and other nucleotide triphosphates, which are important in biochemistry. The term pyrophosphate is also the name of esters formed by the condensation of a phosphorylated biological compound with inorganic phosphate, as for dimethylallyl pyrophosphate. This bond is also referred to as a high-energy phosphate bond.

Pyrophosphate

  Phosphorus, P
  Oxygen, O
Names
IUPAC name
Diphosphate
Systematic IUPAC name
Dipolyphosphate
Other names
Pyrophosphate
Phosphonatophosphate
Identifiers
  • 14000-31-8 Y
  • 13472-36-1 (tetrasodium decahydrate salt) N
  • 7758-16-9 (disodium salt) N
3D model (JSmol)
  • Interactive image
ChEBI
  • CHEBI:18361 Y
ChemSpider
  • 559142 Y
DrugBank
  • DB04160 Y
E number E450 (thickeners, ...)
26938
  • 644102
UNII
  • X3SSV2V6L3
  • InChI=1S/H4O7P2/c1-8(2,3)7-9(4,5)6/h(H2,1,2,3)(H2,4,5,6)/p-4 Y
    Key: XPPKVPWEQAFLFU-UHFFFAOYSA-J Y
  • InChI=1/H4O7P2/c1-8(2,3)7-9(4,5)6/h(H2,1,2,3)(H2,4,5,6)/p-4
    Key: XPPKVPWEQAFLFU-XBHQNQODAI
  • [O-]P(=O)([O-])OP(=O)([O-])[O-]
Properties
P2O4−7
Molar mass 173.941 g·mol−1
Conjugate acid Pyrophosphoric acid
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 ?)

Acidity edit

Pyrophosphoric acid is a tetraprotic acid, with four distinct pKa's:[1]

H4P2O7 ⇌ [H3P2O7]− + H+, pKa1 = 0.85
[H3P2O7]− ⇌ [H2P2O7]2− + H+, pKa2 = 1.96
[H2P2O7]2− ⇌ [HP2O7]3− + H+, pKa3 = 6.60
[HP2O7]3− ⇌ [P2O7]4− + H+, pKa4 = 9.41

The pKa's occur in two distinct ranges because deprotonations occur on separate phosphate groups. For comparison with the pKa's for phosphoric acid are 2.14, 7.20, and 12.37.

At physiological pH's, pyrophosphate exists as a mixture of doubly and singly protonated forms.

Preparation edit

Disodium pyrophosphate is prepared by thermal condensation of sodium dihydrogen phosphate or by partial deprotonation of pyrophosphoric acid.[2]

Pyrophosphates are generally white or colorless. The alkali metal salts are water-soluble.[3] They are good complexing agents for metal ions (such as calcium and many transition metals) and have many uses in industrial chemistry. Pyrophosphate is the first member of an entire series of polyphosphates.[4]

In biochemistry edit

The anion P2O4−7 is abbreviated PPi, standing for inorganic pyrophosphate. It is formed by the hydrolysis of ATP into AMP in cells.

ATP → AMP + PPi

For example, when a nucleotide is incorporated into a growing DNA or RNA strand by a polymerase, pyrophosphate (PPi) is released. Pyrophosphorolysis is the reverse of the polymerization reaction in which pyrophosphate reacts with the 3′-nucleosidemonophosphate (NMP or dNMP), which is removed from the oligonucleotide to release the corresponding triphosphate (dNTP from DNA, or NTP from RNA).

The pyrophosphate anion has the structure P2O4−7, and is an acid anhydride of phosphate. It is unstable in aqueous solution and hydrolyzes into inorganic phosphate:

P2O4−7 + H2O → 2 HPO2−4

or in biologists' shorthand notation:

PPi + H2O → 2 Pi + 2 H+

In the absence of enzymic catalysis, hydrolysis reactions of simple polyphosphates such as pyrophosphate, linear triphosphate, ADP, and ATP normally proceed extremely slowly in all but highly acidic media.[5]

(The reverse of this reaction is a method of preparing pyrophosphates by heating phosphates.)

This hydrolysis to inorganic phosphate effectively renders the cleavage of ATP to AMP and PPi irreversible, and biochemical reactions coupled to this hydrolysis are irreversible as well.

PPi occurs in synovial fluid, blood plasma, and urine at levels sufficient to block calcification and may be a natural inhibitor of hydroxyapatite formation in extracellular fluid (ECF).[6] Cells may channel intracellular PPi into ECF.[7] ANK is a nonenzymatic plasma-membrane PPi channel that supports extracellular PPi levels.[7] Defective function of the membrane PPi channel ANK is associated with low extracellular PPi and elevated intracellular PPi.[6] Ectonucleotide pyrophosphatase/phosphodiesterase (ENPP) may function to raise extracellular PPi.[7]

From the standpoint of high energy phosphate accounting, the hydrolysis of ATP to AMP and PPi requires two high-energy phosphates, as to reconstitute AMP into ATP requires two phosphorylation reactions.

AMP + ATP → 2 ADP
2 ADP + 2 Pi → 2 ATP

The plasma concentration of inorganic pyrophosphate has a reference range of 0.58–3.78 µM (95% prediction interval).[8]

Terpenes edit

Isopentenyl pyrophosphate converts to geranyl pyrophosphate, the precursor to tens of thousands of terpeness and terpenoids.[9]

 
Isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) condense to produce geranyl pyrophosphate, precursor to all terpenes and terpenoids.

As a food additive edit

Various diphosphates are used as emulsifiers, stabilisers, acidity regulators, raising agents, sequestrants, and water retention agents in food processing.[10] They are classified in the E number scheme under E450:[11]

E450(a): disodium dihydrogen diphosphate; trisodium diphosphate; tetrasodium diphosphate (TSPP); tetrapotassium diphosphate
E450(b): pentasodium and pentapotassium triphosphate
E450(c): sodium and potassium polyphosphates

In particular, various formulations of diphosphates are used to stabilize whipped cream.[12]

See also edit

References edit

  1. ^ Yadav, Prerna; Blacque, Olivier; Roodt, Andreas; Zelder, Felix (2021). "Induced fit activity-based sensing: A mechanistic study of pyrophosphate detection with a "flexible" Fe-salen complex". Inorganic Chemistry Frontiers. 8 (19): 4313–4323. doi:10.1039/d1qi00209k. PMC 8477187. PMID 34603734.
  2. ^ Bell, R. N. (1950). "Sodium Pyrophosphates (Sodium Diphosphates)". Inorganic Syntheses. Inorganic Syntheses. Vol. 3. pp. 98–101. doi:10.1002/9780470132340.ch24. ISBN 9780470132340.
  3. ^ C.Michael Hogan. 2011. Phosphate. Encyclopedia of Earth. Topic ed. Andy Jorgensen. Ed.-in-Chief C.J.Cleveland. National Council for Science and the Environment. Washington DC
  4. ^ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
  5. ^ Van Wazer JR, Griffith EJ, McCullough JF (Jan 1955). "Structure and Properties of the Condensed Phosphates. VII. Hydrolytic Degradation of Pyro- and Tripolyphosphate". J. Am. Chem. Soc. 77 (2): 287–291. doi:10.1021/ja01607a011.
  6. ^ a b Ho AM, Johnson MD, Kingsley DM (Jul 2000). "Role of the mouse ank gene in control of tissue calcification and arthritis". Science. 289 (5477): 265–70. Bibcode:2000Sci...289..265H. doi:10.1126/science.289.5477.265. PMID 10894769.
  7. ^ a b c Rutsch F, Vaingankar S, Johnson K, Goldfine I, Maddux B, Schauerte P, Kalhoff H, Sano K, Boisvert WA, Superti-Furga A, Terkeltaub R (Feb 2001). "PC-1 nucleoside triphosphate pyrophosphohydrolase deficiency in idiopathic infantile arterial calcification". Am J Pathol. 158 (2): 543–54. doi:10.1016/S0002-9440(10)63996-X. PMC 1850320. PMID 11159191.
  8. ^ Ryan LM, Kozin F, McCarty DJ (1979). "Quantification of human plasma inorganic pyrophosphate. I. Normal values in osteoarthritis and calcium pyrophosphate dihydrate crystal deposition disease". Arthritis Rheum. 22 (8): 886–91. doi:10.1002/art.1780220812. PMID 223577.
  9. ^ Eberhard Breitmaier (2006). "Hemi‐ and Monoterpenes". Terpenes: Flavors, Fragrances, Pharmaca, Pheromones. pp. 10–23. doi:10.1002/9783527609949.ch2. ISBN 9783527609949.
  10. ^ Codex Alimentarius 1A, 2nd ed, 1995, pp. 71, 82, 91
  11. ^ D. J. Jukes, Food Legislation of the UK: A Concise Guide, Elsevier, 2013, p. 60–61
  12. ^ Ricardo A. Molins, Phosphates in Food, p. 115

Further reading edit

  • Schröder HC, Kurz L, Muller WE, Lorenz B (Mar 2000). (PDF). Biochemistry (Moscow). 65 (3): 296–303. PMID 10739471. Archived from the original (PDF) on 2011-08-25.

External links edit

 
Look up diphosphate or pyrophosphate in Wiktionary, the free dictionary.
  •   Media related to Pyrophosphates at Wikimedia Commons
  • Pyrophosphates at the U.S. National Library of Medicine Medical Subject Headings (MeSH)

February 16, 2024
pyrophosphate, diphosphate, redirects, here, also, refer, salt, containing, phosphate, groups, chemistry, pyrophosphates, phosphorus, oxyanions, that, contain, phosphorus, atoms, linkage, number, pyrophosphate, salts, exist, such, disodium, pyrophosphate, na2h. Diphosphate redirects here It can also refer to any salt containing two phosphate groups In chemistry pyrophosphates are phosphorus oxyanions that contain two phosphorus atoms in a P O P linkage A number of pyrophosphate salts exist such as disodium pyrophosphate Na2H2P2O7 and tetrasodium pyrophosphate Na4P2O7 among others Often pyrophosphates are called diphosphates The parent pyrophosphates are derived from partial or complete neutralization of pyrophosphoric acid The pyrophosphate bond is also sometimes referred to as a phosphoanhydride bond a naming convention which emphasizes the loss of water that occurs when two phosphates form a new P O P bond and which mirrors the nomenclature for anhydrides of carboxylic acids Pyrophosphates are found in ATP and other nucleotide triphosphates which are important in biochemistry The term pyrophosphate is also the name of esters formed by the condensation of a phosphorylated biological compound with inorganic phosphate as for dimethylallyl pyrophosphate This bond is also referred to as a high energy phosphate bond Pyrophosphate Phosphorus P Oxygen ONamesIUPAC name DiphosphateSystematic IUPAC name DipolyphosphateOther names PyrophosphatePhosphonatophosphateIdentifiersCAS Number 14000 31 8 Y13472 36 1 tetrasodium decahydrate salt N7758 16 9 disodium salt N3D model JSmol Interactive imageChEBI CHEBI 18361 YChemSpider 559142 YDrugBank DB04160 YE number E450 thickeners Gmelin Reference 26938PubChem CID 644102UNII X3SSV2V6L3InChI InChI 1S H4O7P2 c1 8 2 3 7 9 4 5 6 h H2 1 2 3 H2 4 5 6 p 4 YKey XPPKVPWEQAFLFU UHFFFAOYSA J YInChI 1 H4O7P2 c1 8 2 3 7 9 4 5 6 h H2 1 2 3 H2 4 5 6 p 4Key XPPKVPWEQAFLFU XBHQNQODAISMILES O P O O OP O O O PropertiesChemical formula P2O4 7Molar mass 173 941 g mol 1Conjugate acid Pyrophosphoric acidExcept 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 Acidity 2 Preparation 3 In biochemistry 3 1 Terpenes 4 As a food additive 5 See also 6 References 7 Further reading 8 External linksAcidity editPyrophosphoric acid is a tetraprotic acid with four distinct pKa s 1 H4P2O7 H3P2O7 H pKa1 0 85 H3P2O7 H2P2O7 2 H pKa2 1 96 H2P2O7 2 HP2O7 3 H pKa3 6 60 HP2O7 3 P2O7 4 H pKa4 9 41The pKa s occur in two distinct ranges because deprotonations occur on separate phosphate groups For comparison with the pKa s for phosphoric acid are 2 14 7 20 and 12 37 At physiological pH s pyrophosphate exists as a mixture of doubly and singly protonated forms Preparation editDisodium pyrophosphate is prepared by thermal condensation of sodium dihydrogen phosphate or by partial deprotonation of pyrophosphoric acid 2 Pyrophosphates are generally white or colorless The alkali metal salts are water soluble 3 They are good complexing agents for metal ions such as calcium and many transition metals and have many uses in industrial chemistry Pyrophosphate is the first member of an entire series of polyphosphates 4 In biochemistry editThe anion P2O4 7 is abbreviated PPi standing for inorganic pyrophosphate It is formed by the hydrolysis of ATP into AMP in cells ATP AMP PPiFor example when a nucleotide is incorporated into a growing DNA or RNA strand by a polymerase pyrophosphate PPi is released Pyrophosphorolysis is the reverse of the polymerization reaction in which pyrophosphate reacts with the 3 nucleosidemonophosphate NMP or dNMP which is removed from the oligonucleotide to release the corresponding triphosphate dNTP from DNA or NTP from RNA The pyrophosphate anion has the structure P2O4 7 and is an acid anhydride of phosphate It is unstable in aqueous solution and hydrolyzes into inorganic phosphate P2O4 7 H2O 2 HPO2 4or in biologists shorthand notation PPi H2O 2 Pi 2 H In the absence of enzymic catalysis hydrolysis reactions of simple polyphosphates such as pyrophosphate linear triphosphate ADP and ATP normally proceed extremely slowly in all but highly acidic media 5 The reverse of this reaction is a method of preparing pyrophosphates by heating phosphates This hydrolysis to inorganic phosphate effectively renders the cleavage of ATP to AMP and PPi irreversible and biochemical reactions coupled to this hydrolysis are irreversible as well PPi occurs in synovial fluid blood plasma and urine at levels sufficient to block calcification and may be a natural inhibitor of hydroxyapatite formation in extracellular fluid ECF 6 Cells may channel intracellular PPi into ECF 7 ANK is a nonenzymatic plasma membrane PPi channel that supports extracellular PPi levels 7 Defective function of the membrane PPi channel ANK is associated with low extracellular PPi and elevated intracellular PPi 6 Ectonucleotide pyrophosphatase phosphodiesterase ENPP may function to raise extracellular PPi 7 From the standpoint of high energy phosphate accounting the hydrolysis of ATP to AMP and PPi requires two high energy phosphates as to reconstitute AMP into ATP requires two phosphorylation reactions AMP ATP 2 ADP 2 ADP 2 Pi 2 ATPThe plasma concentration of inorganic pyrophosphate has a reference range of 0 58 3 78 µM 95 prediction interval 8 Terpenes edit Isopentenyl pyrophosphate converts to geranyl pyrophosphate the precursor to tens of thousands of terpeness and terpenoids 9 nbsp Isopentenyl pyrophosphate IPP and dimethylallyl pyrophosphate DMAPP condense to produce geranyl pyrophosphate precursor to all terpenes and terpenoids As a food additive editVarious diphosphates are used as emulsifiers stabilisers acidity regulators raising agents sequestrants and water retention agents in food processing 10 They are classified in the E number scheme under E450 11 E450 a disodium dihydrogen diphosphate trisodium diphosphate tetrasodium diphosphate TSPP tetrapotassium diphosphate E450 b pentasodium and pentapotassium triphosphate E450 c sodium and potassium polyphosphatesIn particular various formulations of diphosphates are used to stabilize whipped cream 12 See also editAdenosine monophosphate Adenosine diphosphate Adenosine triphosphate ATPase ATP hydrolysis ATP synthase Biochemistry Bone Calcium pyrophosphate Calcium pyrophosphate dihydrate deposition disease Catalysis DNA High energy phosphate Inorganic pyrophosphatase Nucleoside triphosphate Nucleotide Organophosphate Oxidative phosphorylation Phosphate Phosphoric acid Phosphoric acids and phosphates RNA Sodium pyrophosphate Superphosphate Thiamine pyrophosphate Tooth Zinc pyrophosphateReferences edit Yadav Prerna Blacque Olivier Roodt Andreas Zelder Felix 2021 Induced fit activity based sensing A mechanistic study of pyrophosphate detection with a flexible Fe salen complex Inorganic Chemistry Frontiers 8 19 4313 4323 doi 10 1039 d1qi00209k PMC 8477187 PMID 34603734 Bell R N 1950 Sodium Pyrophosphates Sodium Diphosphates Inorganic Syntheses Inorganic Syntheses Vol 3 pp 98 101 doi 10 1002 9780470132340 ch24 ISBN 9780470132340 C Michael Hogan 2011 Phosphate Encyclopedia of Earth Topic ed Andy Jorgensen Ed in Chief C J Cleveland National Council for Science and the Environment Washington DC Greenwood Norman N Earnshaw Alan 1997 Chemistry of the Elements 2nd ed Butterworth Heinemann ISBN 978 0 08 037941 8 Van Wazer JR Griffith EJ McCullough JF Jan 1955 Structure and Properties of the Condensed Phosphates VII Hydrolytic Degradation of Pyro and Tripolyphosphate J Am Chem Soc 77 2 287 291 doi 10 1021 ja01607a011 a b Ho AM Johnson MD Kingsley DM Jul 2000 Role of the mouse ank gene in control of tissue calcification and arthritis Science 289 5477 265 70 Bibcode 2000Sci 289 265H doi 10 1126 science 289 5477 265 PMID 10894769 a b c Rutsch F Vaingankar S Johnson K Goldfine I Maddux B Schauerte P Kalhoff H Sano K Boisvert WA Superti Furga A Terkeltaub R Feb 2001 PC 1 nucleoside triphosphate pyrophosphohydrolase deficiency in idiopathic infantile arterial calcification Am J Pathol 158 2 543 54 doi 10 1016 S0002 9440 10 63996 X PMC 1850320 PMID 11159191 Ryan LM Kozin F McCarty DJ 1979 Quantification of human plasma inorganic pyrophosphate I Normal values in osteoarthritis and calcium pyrophosphate dihydrate crystal deposition disease Arthritis Rheum 22 8 886 91 doi 10 1002 art 1780220812 PMID 223577 Eberhard Breitmaier 2006 Hemi and Monoterpenes Terpenes Flavors Fragrances Pharmaca Pheromones pp 10 23 doi 10 1002 9783527609949 ch2 ISBN 9783527609949 Codex Alimentarius 1A 2nd ed 1995 pp 71 82 91 D J Jukes Food Legislation of the UK A Concise Guide Elsevier 2013 p 60 61 Ricardo A Molins Phosphates in Food p 115Further reading editSchroder HC Kurz L Muller WE Lorenz B Mar 2000 Polyphosphate in bone PDF Biochemistry Moscow 65 3 296 303 PMID 10739471 Archived from the original PDF on 2011 08 25 External links edit nbsp Look up diphosphate or pyrophosphate in Wiktionary the free dictionary nbsp Media related to Pyrophosphates at Wikimedia Commons Pyrophosphates at the U S National Library of Medicine Medical Subject Headings MeSH Retrieved from https en wikipedia org w index php title Pyrophosphate amp oldid 1191775620, wikipedia, wiki, book, books, library,

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