Diisopropyl fluorophosphate

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Diisopropyl fluorophosphate
Diisopropylfluorophosphate.svg
Diisopropyl-fluorophosphate-3D-balls.png
Clinical data
Other namesIsofluorophate, Isofluorphate, DFP, DIFP, DIPF, Diisopropyl phosphorofluoridate, EA-1152, PF-3, T-1703, TL-466
ATC code
Identifiers
  • bis(propan-2-yl) fluorophosphonate
CAS Number
PubChem CID
DrugBank
ChemSpider
UNII
KEGG
ChEBI
ChEMBL
CompTox Dashboard (EPA)
ECHA InfoCard 100.000.225 OOjs UI icon edit-ltr-progressive.svg
Chemical and physical data
Formula C6H14FO3P
Molar mass 184.147 g·mol−1
3D model (JSmol)
Melting point −82 °C (−116 °F)
Boiling point 183 °C (361 °F) 1013 mbar
  • FP(=O)(OC(C)C)OC(C)C
  • InChI=1S/C6H14FO3P/c1-5(2)9-11(7,8)10-6(3)4/h5-6H,1-4H3 Yes check.svgY
  • Key:MUCZHBLJLSDCSD-UHFFFAOYSA-N Yes check.svgY
   (verify)

Diisopropyl fluorophosphate (DFP) or Isoflurophate is an oily, colorless liquid with the chemical formula C6H14FO3P. It is used in medicine [1] and as an organophosphorus insecticide. [2] It is stable, but undergoes hydrolysis when subjected to moisture.

Contents

Uses in medicine

Diisopropyl fluorophosphate is a parasympathomimetic drug irreversible anti-cholinesterase and has been used in ophthalmology as a miotic agent in treatment of chronic glaucoma, as a miotic in veterinary medicine, and as an experimental agent in neuroscience because of its acetylcholinesterase inhibitory properties and ability to induce delayed peripheral neuropathy. [1]

Uses as toxin

Reaction of the DIFP with a serine protease DIFP serine inactivation.svg
Reaction of the DIFP with a serine protease

The marked toxicity of esters of monofluorophosphoric acid was discovered in 1932, when Willy Lange and his PhD student Gerda von Krueger prepared the methyl, ethyl, n-propyl, and n-butyl esters and incidentally experienced their toxic effects. Another homologue of this series of esters, Diisopropyl fluorophosphate, was developed by British scientist Bernard Charles Saunders. On his search for compounds to be used as chemical warfare agents, Saunders was inspired by the report by Lange and Krueger and decided to prepare the new homologue which he labeled PF-3. It was much less effective as a chemical weapon than the G series agents. It was often mixed with mustard gas, forming a more effective mixture with significantly lower melting point, resulting in an agent suitable for use in cold weather.

Crystal structure of Herpes Simplex Virus Protease/Inhibitor (DFP) complex. The active site serine (yellow) has undergone phosphonylation resulting in irreversible inhibition. Rendered from PDB 1AT3. Crystal structure of Herpes Simplex Virus Protease-Inhibitor (DFP) complex.jpg
Crystal structure of Herpes Simplex Virus Protease/Inhibitor (DFP) complex. The active site serine (yellow) has undergone phosphonylation resulting in irreversible inhibition. Rendered from PDB 1AT3.

In military research, due to its physical and chemical similarities and comparatively low toxicity, it is used as a simulant of G-agents (GA, GB, GD, and GF). Diisopropyl fluorophosphate is used in civilian laboratories to mimic lethal nerve gas exposure or organophosphate toxicities. [3] [4] [5] It has also been used to develop a rodent model of Gulf War Syndrome. [6]

Diisopropyl fluorophosphate is a very potent neurotoxin. Its LD50 in rats is 6 mg/kg (oral). It combines with the amino acid serine at the active site of the enzyme acetylcholinesterase, [7] an enzyme that deactivates the neurotransmitter acetylcholine. Neurotransmitters are needed to continue the passage of nerve impulses from one neuron to another across the synapse. Once the impulse has been transmitted, acetylcholinesterase functions to deactivate the acetylcholine almost immediately by breaking it down. If the enzyme is inhibited, acetylcholine accumulates and nerve impulses cannot be stopped, causing prolonged muscle contraction. Paralysis occurs and death may result since the respiratory muscles are affected.

DFP also inhibits some proteases. It is a useful additive for protein or cell isolation procedure.

Diisopropyl fluorophosphate (DFP) was a nerve gas developed by the German during the Second World War. DFP irreversibly binds with the enzymes containing serine at the active site, e g. Serine proteases, acetylcholine esterase.

Production

Isoflurophate, the diisopropyl ester of fluorophosphoric acid, is made by reacting isopropyl alcohol with phosphorus trichloride, forming diisopropylphosphite, which is chlorinated and further reacted with sodium fluoride to replace the chlorine atom with fluorine, thus giving diisopropyl fluorophosphate. [8]

DIFP synthesis.svg

Biochemistry

DFP is a diagnostic test for the presence of the active site Ser in serine proteases, as well as a serine protease inhibitor. PMSF and AEBSF are alternative, less toxic, but presumably also less reactive, reagents for these same applications. DFP and other analogous organophosphate neurotoxins are inactivated by the enzyme paraoxonase, which is present in widely varying levels in humans.

Society and culture

It is marketed under many brand names including Difluorophate, Diflupyl, Diflurphate, Dyflos, Dyphlos, Fluropryl, Fluostigmine, Neoglaucit.[ citation needed ]

See also

Related Research Articles

Nerve agents, sometimes also called nerve gases, are a class of organic chemicals that disrupt the mechanisms by which nerves transfer messages to organs. The disruption is caused by the blocking of acetylcholinesterase (AChE), an enzyme that catalyzes the breakdown of acetylcholine, a neurotransmitter. Nerve agents are irreversible acetylcholinesterase inhibitors used as poison.

<span class="mw-page-title-main">Sarin</span> Chemical compound and chemical warfare nerve agent

Sarin is an extremely toxic organophosphorus compound. A colourless, odourless liquid, it is used as a chemical weapon due to its extreme potency as a nerve agent. Exposure can be lethal even at very low concentrations, where death can occur within one to ten minutes after direct inhalation of a lethal dose, due to suffocation from respiratory paralysis, unless antidotes are quickly administered. People who absorb a non-lethal dose and do not receive immediate medical treatment may suffer permanent neurological damage.

<span class="mw-page-title-main">Soman</span> Chemical compound (nerve agent)

Soman is an extremely toxic chemical substance. It is a nerve agent, interfering with normal functioning of the mammalian nervous system by inhibiting the enzyme cholinesterase. It is an inhibitor of both acetylcholinesterase and butyrylcholinesterase. As a chemical weapon, it is classified as a weapon of mass destruction by the United Nations according to UN Resolution 687. Its production is strictly controlled, and stockpiling is outlawed by the Chemical Weapons Convention of 1993 where it is classified as a Schedule 1 substance. Soman was the third of the so-called G-series nerve agents to be discovered along with GA (tabun), GB (sarin), and GF (cyclosarin).

<span class="mw-page-title-main">VX (nerve agent)</span> Chemical compound and chemical warfare nerve agent

VX is an extremely toxic synthetic chemical compound in the organophosphorus class, specifically, a thiophosphonate. In the class of nerve agents, it was developed for military use in chemical warfare after translation of earlier discoveries of organophosphate toxicity in pesticide research. In its pure form, VX is an oily, relatively non-volatile liquid that is amber-like in colour. Because of its low volatility, VX persists in environments where it is dispersed.

<span class="mw-page-title-main">Cholinesterase</span> Esterase that lyses choline-based esters

The enzyme cholinesterase (EC 3.1.1.8, choline esterase; systematic name acylcholine acylhydrolase) catalyses the hydrolysis of choline-based esters:

<span class="mw-page-title-main">Sodium monofluorophosphate</span> Chemical compound

Sodium monofluorophosphate, commonly abbreviated SMFP, is an inorganic compound with the chemical formula Na2PO3F. Typical for a salt, SMFP is odourless, colourless, and water-soluble. This salt is an ingredient in some toothpastes.

<span class="mw-page-title-main">AEBSF</span> Chemical compound

AEBSF or 4-(2-aminoethyl)benzenesulfonyl fluoride hydrochloride is a water-soluble, irreversible serine protease inhibitor with a molecular weight of 239.5 Da. It inhibits proteases like chymotrypsin, kallikrein, plasmin, thrombin, and trypsin. The specificity is similar to the inhibitor PMSF, nevertheless AEBSF is more stable at low pH values. Typical usage is 0.1 - 1.0 mM. AEBSF was first reported for use in biochemistry in 1993, and came into common use for the inhibition serine proteases and of non-protease enzymes such as acetylhydrolases in the mid 1990s.

<span class="mw-page-title-main">Enzyme inhibitor</span> Molecule that blocks enzyme activity

An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity. Enzymes are proteins that speed up chemical reactions necessary for life, in which substrate molecules are converted into products. An enzyme facilitates a specific chemical reaction by binding the substrate to its active site, a specialized area on the enzyme that accelerates the most difficult step of the reaction.

<span class="mw-page-title-main">Azinphos-methyl</span> Chemical compound

Azinphos-methyl (Guthion) is a broad spectrum organophosphate insecticide manufactured by Bayer CropScience, Gowan Co., and Makhteshim Agan. Like other pesticides in this class, it owes its insecticidal properties to the fact that it is an acetylcholinesterase inhibitor. It is classified as an extremely hazardous substance in the United States as defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act, and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.

<span class="mw-page-title-main">PMSF</span> Chemical compound

In biochemistry, phenylmethylsulfonyl fluoride (PMSF) is a serine protease inhibitor commonly used in the preparation of cell lysates. PMSF does not inactivate all serine proteases. The effective concentration of PMSF is between 0.1 - 1 mM. The half-life is short in aqueous solutions. At 4˚C, pH 8, PMSF is almost completely degraded after 1 day. Stock solutions are usually made up in anhydrous ethanol, isopropanol, or corn oil and diluted immediately before use.

<span class="mw-page-title-main">Phosmet</span> Organophosphate non-systemic insecticide

Phosmet is a phthalimide-derived, non-systemic, organophosphate insecticide used on plants and animals. It is mainly used on apple trees for control of codling moth, though it is also used on a wide range of fruit crops, ornamentals, and vines for the control of aphids, suckers, mites, and fruit flies.

<span class="mw-page-title-main">Acetylcholinesterase</span> Primary cholinesterase in the body

Acetylcholinesterase (HGNC symbol ACHE; EC 3.1.1.7; systematic name acetylcholine acetylhydrolase), also known as AChE, AChase or acetylhydrolase, is the primary cholinesterase in the body. It is an enzyme that catalyzes the breakdown of acetylcholine and some other choline esters that function as neurotransmitters:

<span class="mw-page-title-main">Proteinase K</span> Broad-spectrum serine protease

In molecular biology, Proteinase K is a broad-spectrum serine protease. The enzyme was discovered in 1974 in extracts of the fungus Parengyodontium album. Proteinase K is able to digest hair (keratin), hence, the name "Proteinase K". The predominant site of cleavage is the peptide bond adjacent to the carboxyl group of aliphatic and aromatic amino acids with blocked alpha amino groups. It is commonly used for its broad specificity. This enzyme belongs to Peptidase family S8 (subtilisin). The molecular weight of Proteinase K is 28,900 daltons.

<span class="mw-page-title-main">Diisopropyl-fluorophosphatase</span>

The enzyme diisopropyl-fluorophosphatase (EC 3.1.8.2) catalyzes the reaction

<span class="mw-page-title-main">Acetylcholinesterase inhibitor</span> Drugs that inhibit acetylcholinesterase

Acetylcholinesterase inhibitors (AChEIs) also often called cholinesterase inhibitors, inhibit the enzyme acetylcholinesterase from breaking down the neurotransmitter acetylcholine into choline and acetate, thereby increasing both the level and duration of action of acetylcholine in the central nervous system, autonomic ganglia and neuromuscular junctions, which are rich in acetylcholine receptors. Acetylcholinesterase inhibitors are one of two types of cholinesterase inhibitors; the other being butyryl-cholinesterase inhibitors. Acetylcholinesterase is the primary member of the cholinesterase enzyme family.

<span class="mw-page-title-main">Tetraethyl pyrophosphate</span> Chemical compound

Tetraethyl pyrophosphate, abbreviated TEPP, is an organophosphate compound with the formula [(C2H5O)2P(O)]2O. It is the tetraethyl derivative of pyrophosphate (P2O74-). It is a colorless oil that solidifies near room temperature. It is used as an insecticide. The compound hydrolyzes rapidly.

Methanesulfonyl fluoride (MSF) has long been known to be a potent inhibitor of acetylcholinesterase (AChE), the enzyme that regulates acetylcholine, an important neurotransmitter in both the central and peripheral nervous systems.

<span class="mw-page-title-main">Monofluorophosphate</span> Chemical compound

Monofluorophosphate is an anion with the formula PO3F2−, which is a phosphate group with one oxygen atom substituted with a fluoride atom. The charge of the ion is −2. The ion resembles sulfate in size, shape and charge, and can thus form compounds with the same structure as sulfates. These include Tutton's salts and langbeinites. The most well-known compound of monofluorophosphate is sodium monofluorophosphate, commonly used in toothpaste.

<span class="mw-page-title-main">IPTBO</span> Chemical compound

IPTBO is a bicyclic phosphate convulsant. It is an extremely potent GABA receptor antagonist that can cause violent convulsions in mice.

References

  1. 1 2 "Isofluorphate definition". Drugs.com. Archived from the original on 6 September 2017. Retrieved 6 September 2017.
  2. ↑ "Isoflurophate". National Cancer Institute. Retrieved 2022-10-30.
  3. ↑ Deshpande LS, Carter DS, Blair RE, DeLorenzo RJ (August 2010). "Development of a prolonged calcium plateau in hippocampal neurons in rats surviving status epilepticus induced by the organophosphate diisopropylfluorophosphate". Toxicological Sciences. 116 (2): 623–31. doi:10.1093/toxsci/kfq157. PMC   2905411 . PMID   20498005.
  4. ↑ Pessah IN, Rogawski MA, Tancredi DJ, Wulff H, Zolkowska D, Bruun DA, et al. (August 2016). "Models to identify treatments for the acute and persistent effects of seizure-inducing chemical threat agents". Annals of the New York Academy of Sciences. 1378 (1): 124–136. doi:10.1111/nyas.13137. PMC   5063690 . PMID   27467073.
  5. ↑ Kadriu B, Guidotti A, Costa E, Davis JM, Auta J (March 2011). "Acute imidazenil treatment after the onset of DFP-induced seizure is more effective and longer lasting than midazolam at preventing seizure activity and brain neuropathology". Toxicological Sciences. 120 (1): 136–45. doi: 10.1093/toxsci/kfq356 . PMID   21097996.
  6. ↑ Phillips KF, Deshpande LS (January 2016). "Repeated low-dose organophosphate DFP exposure leads to the development of depression and cognitive impairment in a rat model of Gulf War Illness". Neurotoxicology. 52: 127–33. doi: 10.1016/j.neuro.2015.11.014 . PMID   26619911.
  7. ↑ Millard CB, Kryger G, Ordentlich A, Greenblatt HM, Harel M, Raves ML, et al. (June 1999). "Crystal structures of aged phosphonylated acetylcholinesterase: nerve agent reaction products at the atomic level". Biochemistry. 38 (22): 7032–9. doi:10.1021/bi982678l. PMID   10353814.
  8. ↑ USpatent 2409039,Hardy, Edgar E&Kosoloapoff, Gennady M,"Halogenated compounds and process for making same",issued 1946-10-08, assigned to Monsanto Chemical Company

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