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Identification
NamePicrotoxin
Accession NumberDB00466  (APRD00269)
TypeSmall Molecule
GroupsExperimental
DescriptionA noncompetitive antagonist at GABA-A receptors and thus a convulsant. Picrotoxin blocks the gamma-aminobutyric acid-activated chloride ionophore. Although it is most often used as a research tool, it has been used as a CNS stimulant and an antidote in poisoning by CNS depressants, especially the barbiturates. [PubChem]
Structure
Thumb
Synonyms
cocculin
External Identifiers Not Available
Approved Prescription ProductsNot Available
Approved Generic Prescription ProductsNot Available
Approved Over the Counter ProductsNot Available
Unapproved/Other Products Not Available
International BrandsNot Available
Brand mixturesNot Available
SaltsNot Available
Categories
UNIIZLT174DL7U
CAS number124-87-8
WeightAverage: 602.5832
Monoisotopic: 602.199941174
Chemical FormulaC30H34O13
InChI KeyInChIKey=VJKUPQSHOVKBCO-ZTYBEOBUSA-N
InChI
InChI=1S/C15H18O7.C15H16O6/c1-12(2,18)6-7-10(16)20-8(6)9-13(3)14(7,19)4-5-15(13,22-5)11(17)21-9;1-5(2)7-8-11(16)19-9(7)10-13(3)14(8,18)4-6-15(13,21-6)12(17)20-10/h5-9,18-19H,4H2,1-3H3;6-10,18H,1,4H2,2-3H3/t5-,6+,7?,8?,9-,13-,14-,15+;6?,7-,8?,9?,10+,13+,14+,15-/m10/s1
IUPAC Name
(1R,3R,5S,8S,13R,14S)-1-hydroxy-14-(2-hydroxypropan-2-yl)-13-methyl-4,7,10-trioxapentacyclo[6.4.1.1⁹,¹².0³,⁵.0⁵,¹³]tetradecane-6,11-dione; (1R,5S,8S,13R,14R)-1-hydroxy-13-methyl-14-(prop-1-en-2-yl)-4,7,10-trioxapentacyclo[6.4.1.1⁹,¹².0³,⁵.0⁵,¹³]tetradecane-6,11-dione
SMILES
[H][C@@]12OC(=O)[C@@]34OC3C[C@@](O)(C3[C@@H](C1OC3=O)C(C)=C)[C@@]24C.[H][C@@]12C[C@@]3(O)C4[C@@H](C(OC4=O)[C@@]4([H])OC(=O)[C@]1(O2)[C@@]34C)C(C)(C)O
Taxonomy
DescriptionThis compound belongs to the class of organic compounds known as furopyrans. These are organic polycyclic compounds containing a furan ring fused to a pyran ring. Furan is a five-membered aromatic ring with four carbon atoms and one oxygen atom. Pyran a six-membered heterocyclic, non-aromatic ring, made up of five carbon atoms and one oxygen atom and containing two double bonds.
KingdomOrganic compounds
Super ClassOrganoheterocyclic compounds
ClassFuropyrans
Sub ClassNot Available
Direct ParentFuropyrans
Alternative Parents
Substituents
  • Furopyran
  • Caprolactone
  • Oxepane
  • Pyran
  • Oxane
  • Gamma butyrolactone
  • Saccharide
  • Tertiary alcohol
  • Oxolane
  • Furan
  • Cyclic alcohol
  • Lactone
  • Carboxylic acid ester
  • Oxacycle
  • Monocarboxylic acid or derivatives
  • Ether
  • Oxirane
  • Dialkyl ether
  • Carboxylic acid derivative
  • Hydrocarbon derivative
  • Organooxygen compound
  • Carbonyl group
  • Alcohol
  • Aliphatic heteropolycyclic compound
Molecular FrameworkNot Available
External DescriptorsNot Available
Pharmacology
IndicationUsed internally for relieving respiratory distress. Also for use as an antidote in poisoning by CNS depressants, especially barbiturates.
PharmacodynamicsPicrotoxin is a toxin obtained from the seeds of the shrub Anamirta cocculus. It is used as a central nervous system stimulant, antidote, convulsant, and GABA (gamma aminobutyric acid) antagonist. It is a noncompetitive antagonist at GABAA receptors and thus a convulsant. Picrotoxin blocks the GABAActivated chloride ionophore. Although it is most often used as a research tool, it has been used as a CNS stimulant and an antidote in poisoning by CNS depressants, especially barbiturates.
Mechanism of actionPicrotoxin antagonizes the GABAA receptor channel directly, which is a ligand-gated ion channel concerned chiefly with the passing of chloride ions across the cell membrane. Therefore picrotoxin prevents Cl- channel permeability and thus promtes an inhibitory influence on the target neuron. Picrotoxin reduces conductance through the channel by reducing not only the opening frequency but also the mean open time. Picrotoxin also antagonizes GABAC receptors (also called GABAA-rho receptors) but the result of this action is not known. The GABAC receptor is also linked to chloride channels, with distinct physiological and pharmacological properties. In contrast to the fast and transient responses elicited from GABAA receptors, GABAC receptors mediate slow and sustained responses.
Related Articles
AbsorptionNot Available
Volume of distributionNot Available
Protein bindingNot Available
MetabolismNot Available
Route of eliminationNot Available
Half lifeNot Available
ClearanceNot Available
ToxicityOral, mouse: LD50 = 15 mg/kg. In large doses it is a powerful poison, causing unconsciousness, delirium, convulsions, gastro-enteritis and stimulation of the respiratory centre followed by paralysis, from which death sometimes results.
Affected organisms
  • Humans and other mammals
PathwaysNot Available
SNP Mediated EffectsNot Available
SNP Mediated Adverse Drug ReactionsNot Available
ADMET
Predicted ADMET features
PropertyValueProbability
Human Intestinal Absorption+0.8434
Blood Brain Barrier+0.5
Caco-2 permeable-0.6151
P-glycoprotein substrateSubstrate0.794
P-glycoprotein inhibitor IInhibitor0.7418
P-glycoprotein inhibitor IINon-inhibitor0.9201
Renal organic cation transporterNon-inhibitor0.8832
CYP450 2C9 substrateNon-substrate0.8446
CYP450 2D6 substrateNon-substrate0.866
CYP450 3A4 substrateSubstrate0.6596
CYP450 1A2 substrateNon-inhibitor0.8981
CYP450 2C9 inhibitorNon-inhibitor0.9071
CYP450 2D6 inhibitorNon-inhibitor0.9307
CYP450 2C19 inhibitorNon-inhibitor0.8809
CYP450 3A4 inhibitorNon-inhibitor0.5167
CYP450 inhibitory promiscuityLow CYP Inhibitory Promiscuity0.929
Ames testAMES toxic0.6089
CarcinogenicityNon-carcinogens0.9354
BiodegradationNot ready biodegradable1.0
Rat acute toxicity3.2615 LD50, mol/kg Not applicable
hERG inhibition (predictor I)Weak inhibitor0.9951
hERG inhibition (predictor II)Non-inhibitor0.9013
ADMET data is predicted using admetSAR, a free tool for evaluating chemical ADMET properties. (23092397 )
Pharmacoeconomics
ManufacturersNot Available
PackagersNot Available
Dosage formsNot Available
PricesNot Available
PatentsNot Available
Properties
StateSolid
Experimental Properties
PropertyValueSource
melting point203.5 °CPhysProp
water solubility4100 mg/LYALKOWSKY,SH & DANNENFELSER,RM (1992)
logP-2.229Not Available
Predicted Properties
PropertyValueSource
logP-1.1ChemAxon
pKa (Strongest Acidic)13.6ChemAxon
pKa (Strongest Basic)-2.8ChemAxon
Physiological Charge0ChemAxon
Hydrogen Acceptor Count5ChemAxon
Hydrogen Donor Count2ChemAxon
Polar Surface Area105.59 Å2ChemAxon
Rotatable Bond Count2ChemAxon
Refractivity68.29 m3·mol-1ChemAxon
Polarizability28.53 Å3ChemAxon
Number of Rings10ChemAxon
Bioavailability1ChemAxon
Rule of FiveYesChemAxon
Ghose FilterYesChemAxon
Veber's RuleYesChemAxon
MDDR-like RuleYesChemAxon
Spectra
Mass Spec (NIST)Not Available
Spectra
Spectrum TypeDescriptionSplash Key
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, PositiveNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 10V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 20V, NegativeNot Available
Predicted LC-MS/MSPredicted LC-MS/MS Spectrum - 40V, NegativeNot Available
MSMass Spectrum (Electron Ionization)splash10-0a4m-9400000000-4265da630cb3536f0c8dView in MoNA
References
Synthesis ReferenceNot Available
General References
  1. Ehrenberger K, Benkoe E, Felix D: Suppressive action of picrotoxin, a GABA antagonist, on labyrinthine spontaneous nystagmus and vertigo in man. Acta Otolaryngol. 1982;93(1-6):269-73. [PubMed:7064710 ]
  2. Link [Link]
External Links
ATC CodesNot Available
AHFS Codes
  • 92:02.00*
PDB EntriesNot Available
FDA labelNot Available
MSDSDownload (75.2 KB)
Interactions
Drug InteractionsNot Available
Food InteractionsNot Available

Targets

Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
antagonist
General Function:
Gaba-a receptor activity
Specific Function:
GABA, the major inhibitory neurotransmitter in the vertebrate brain, mediates neuronal inhibition by binding to the GABA/benzodiazepine receptor and opening an integral chloride channel. Rho-1 GABA receptor could play a role in retinal neurotransmission.
Gene Name:
GABRR1
Uniprot ID:
P24046
Molecular Weight:
55882.91 Da
References
  1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. [PubMed:17139284 ]
  2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. [PubMed:17016423 ]
  3. Law RJ, Lightstone FC: Gaba receptor insecticide non-competitive antagonists may bind at allosteric modulator sites. Int J Neurosci. 2008 May;118(5):705-34. doi: 10.1080/00207450701750216. [PubMed:18446586 ]
  4. Richter D, Luhmann HJ, Kilb W: Intrinsic activation of GABA(A) receptors suppresses epileptiform activity in the cerebral cortex of immature mice. Epilepsia. 2010 Aug;51(8):1483-92. doi: 10.1111/j.1528-1167.2010.02591.x. Epub 2010 May 14. [PubMed:20491873 ]
Kind
Protein
Organism
Human
Pharmacological action
yes
Actions
antagonist
General Function:
Inhibitory extracellular ligand-gated ion channel activity
Specific Function:
Component of the heteropentameric receptor for GABA, the major inhibitory neurotransmitter in the vertebrate brain. Functions also as histamine receptor and mediates cellular responses to histamine. Functions as receptor for diazepines and various anesthetics, such as pentobarbital; these are bound at a separate allosteric effector binding site. Functions as ligand-gated chloride channel (By si...
Gene Name:
GABRA1
Uniprot ID:
P14867
Molecular Weight:
51801.395 Da
References
  1. Overington JP, Al-Lazikani B, Hopkins AL: How many drug targets are there? Nat Rev Drug Discov. 2006 Dec;5(12):993-6. [PubMed:17139284 ]
  2. Imming P, Sinning C, Meyer A: Drugs, their targets and the nature and number of drug targets. Nat Rev Drug Discov. 2006 Oct;5(10):821-34. [PubMed:17016423 ]
  3. Law RJ, Lightstone FC: Gaba receptor insecticide non-competitive antagonists may bind at allosteric modulator sites. Int J Neurosci. 2008 May;118(5):705-34. doi: 10.1080/00207450701750216. [PubMed:18446586 ]
  4. Richter D, Luhmann HJ, Kilb W: Intrinsic activation of GABA(A) receptors suppresses epileptiform activity in the cerebral cortex of immature mice. Epilepsia. 2010 Aug;51(8):1483-92. doi: 10.1111/j.1528-1167.2010.02591.x. Epub 2010 May 14. [PubMed:20491873 ]
  5. Chen X, Ji ZL, Chen YZ: TTD: Therapeutic Target Database. Nucleic Acids Res. 2002 Jan 1;30(1):412-5. [PubMed:11752352 ]
Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
antagonist
General Function:
Transmitter-gated ion channel activity
Specific Function:
The glycine receptor is a neurotransmitter-gated ion channel. Binding of glycine to its receptor increases the chloride conductance and thus produces hyperpolarization (inhibition of neuronal firing).
Gene Name:
GLRA2
Uniprot ID:
P23416
Molecular Weight:
52001.585 Da
References
  1. Yang Z, Cromer BA, Harvey RJ, Parker MW, Lynch JW: A proposed structural basis for picrotoxinin and picrotin binding in the glycine receptor pore. J Neurochem. 2007 Oct;103(2):580-9. Epub 2007 Aug 20. [PubMed:17714449 ]
  2. Wang DS, Buckinx R, Lecorronc H, Mangin JM, Rigo JM, Legendre P: Mechanisms for picrotoxinin and picrotin blocks of alpha2 homomeric glycine receptors. J Biol Chem. 2007 Jun 1;282(22):16016-35. Epub 2007 Apr 3. [PubMed:17405877 ]
Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
antagonist
General Function:
Transmitter-gated ion channel activity
Specific Function:
The glycine receptor is a neurotransmitter-gated ion channel. Binding of glycine to its receptor increases the chloride conductance and thus produces hyperpolarization (inhibition of neuronal firing).
Gene Name:
GLRA3
Uniprot ID:
O75311
Molecular Weight:
53799.775 Da
References
  1. Yang Z, Cromer BA, Harvey RJ, Parker MW, Lynch JW: A proposed structural basis for picrotoxinin and picrotin binding in the glycine receptor pore. J Neurochem. 2007 Oct;103(2):580-9. Epub 2007 Aug 20. [PubMed:17714449 ]

Enzymes

Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
inducer
General Function:
Vitamin d 24-hydroxylase activity
Specific Function:
Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics.
Gene Name:
CYP1A1
Uniprot ID:
P04798
Molecular Weight:
58164.815 Da
References
  1. Sadar MD, Ash R, Andersson TB: Picrotoxin is a CYP1A1 inducer in rainbow trout hepatocytes. Biochem Biophys Res Commun. 1995 Sep 25;214(3):1060-6. [PubMed:7575510 ]
  2. Sadar MD, Westlind A, Blomstrand F, Andersson TB: Induction of CYP1A1 by GABA receptor ligands. Biochem Biophys Res Commun. 1996 Dec 4;229(1):231-7. [PubMed:8954111 ]
Kind
Protein
Organism
Human
Pharmacological action
unknown
Actions
inhibitor
General Function:
Manganese ion binding
Specific Function:
This enzyme has 2 functions: it catalyzes the production of glutamine and 4-aminobutanoate (gamma-aminobutyric acid, GABA), the latter in a pyridoxal phosphate-independent manner (By similarity). Essential for proliferation of fetal skin fibroblasts.
Gene Name:
GLUL
Uniprot ID:
P15104
Molecular Weight:
42064.15 Da
References
  1. Loscher W, Frey HH: Effect of convulsant and anticonvulsant agents on level and metabolism of gamma-aminobutyric acid in mouse brain. Naunyn Schmiedebergs Arch Pharmacol. 1977 Feb;296(3):263-9. [PubMed:840320 ]
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Drug created on June 13, 2005 07:24 / Updated on August 17, 2016 12:23