Tetrodotoxin

Tetrodotoxin
Names
IUPAC name
(4R,4aR,5R,6S,7S,8S,8aR,10S,12S)-2-azaniumylidene-4,6,8,12-tetrahydroxy-6-(hydroxymethyl)-2,3,4,4a,5,6,7,8-octahydro-1H-8a,10-methano-5,7-(epoxymethanooxy)quinazolin-10-olate
Other names
anhydrotetrodotoxin, 4-epitetrodotoxin, tetrodonic acid, TTX
Identifiers
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.022.236 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C11H17N3O8/c12-8-13-6(17)2-4-9(19,1-15)5-3(16)10(2,14-8)7(18)11(20,21-4)22-5/h2-7,15-20H,1H2,(H3,12,13,14)/t2-,3-,4-,5+,6-,7+,9+,10-,11+/m1/s1 ☒N
    Key: CFMYXEVWODSLAX-QOZOJKKESA-N ☒N
  • InChI=1/C11H17N3O8/c12-8-13-6(17)2-4-9(19,1-15)5-3(16)10(2,14-8)7(18)11(20,21-4)22-5/h2-7,15-20H,1H2,(H3,12,13,14)/t2-,3-,4-,5+,6-,7+,9+,10-,11+/m1/s1
    Key: CFMYXEVWODSLAX-QOZOJKKEBM
  • O1[C@@H]4[C@@](O)([C@@H]3O[C@@]1(O)[C@@H](O)[C@]2(N\C(N/[C@H](O)[C@H]23)=N)[C@@H]4O)CO
  • zwitterion: O1[C@@H]4[C@@](O)([C@@H]3O[C@@]1([O-])[C@@H](O)[C@]2(N\C(N/[C@H](O)[C@H]23)=[NH2+])[C@@H]4O)CO
Properties
C11H17N3O8
Molar mass 319.270 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Tetrodotoxin (TTX) is a potent neurotoxin. Its name derives from Tetraodontiformes, an order that includes pufferfish, porcupinefish, ocean sunfish, and triggerfish; several of these species carry the toxin. Although tetrodotoxin was discovered in these fish, it is found in several other animals (e.g., in blue-ringed octopi, rough-skinned newts, and moon snails). It is also produced by certain infectious or symbiotic bacteria like Pseudoalteromonas, Pseudomonas, and Vibrio as well as other species found in symbiotic relationships with animals and plants.[1][2]

Although it produces thousands of intoxications annually and several deaths,[3] it has shown efficacy for the treatment of cancer-related pain in phase II and III clinical trials.[4]

Tetrodotoxin is a sodium channel blocker. It inhibits the firing of action potentials in neurons by binding to the voltage-gated sodium channels in nerve cell membranes and blocking the passage of sodium ions (responsible for the rising phase of an action potential) into the neuron. This prevents the nervous system from carrying messages and thus muscles from contracting in response to nervous stimulation.[5]

Its mechanism of action – selective blocking of the sodium channel – was shown definitively in 1964 by Toshio Narahashi and John W. Moore at Duke University, using the sucrose gap voltage clamp technique.[6]

  1. ^ Cite error: The named reference Chau_2011 was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference Lago_2015 was invoked but never defined (see the help page).
  3. ^ Guardone L, Maneschi A, Meucci V, Gasperetti L, Nucera D, Armani A (2020-10-02). "A Global Retrospective Study on Human Cases of Tetrodotoxin (TTX) Poisoning after Seafood Consumption". Food Reviews International. 36 (7): 645–667. doi:10.1080/87559129.2019.1669162. hdl:11568/1013333. ISSN 8755-9129. S2CID 204144112.
  4. ^ Huerta MÁ, de la Nava J, Artacho-Cordón A, Nieto FR (May 2023). "Efficacy and Security of Tetrodotoxin in the Treatment of Cancer-Related Pain: Systematic Review and Meta-Analysis". Marine Drugs. 21 (5): 316. doi:10.3390/md21050316. ISSN 1660-3397. PMC 10221257. PMID 37233510.
  5. ^ Bane V, Lehane M, Dikshit M, O'Riordan A, Furey A (February 2014). "Tetrodotoxin: Chemistry, Toxicity, Source, Distribution and Detection". Toxins. 6 (2): 693–755. doi:10.3390/toxins6020693. PMC 3942760. PMID 24566728.
  6. ^ Narahashi T, Moore JW, Scott WR (May 1964). "Tetrodotoxin blockage of sodium conductance increase in lobster giant axons". The Journal of General Physiology. 47 (5): 965–974. doi:10.1085/jgp.47.5.965. PMC 2195365. PMID 14155438.