Ibotenic acid
PubChem records this structure as Ibotenic Acid.
Also known asDL-Ibotenic acid · (RS)-Ibotenic acid · Acid, Ibotenic · (+-)-Ibotenic acid · Ibotenate · (+/-)-Ibotenic acid · (?)-Ibotenic acid · Ibotenic acid, ~95%, solid
2-amino-2-(3-oxo-1,2-oxazol-5-yl)acetic acid
- PubChem CID
- 1233
- ChEMBL
- CHEMBL284895
- Measurements
- 6
- InChIKey
- IRJCBFDCFXCWGO-UHFFFAOYSA-N
I · Summary
What is known
Published passages, each quoted whole and attributed to the database that published it. Two blocks are written here rather than quoted, and both say so where they stand: the synthesized summary at the top, which may draw only on the passages beneath it, and the history note, which cites the works it came from. Every claim in either carries a marker to its source.
What it is
Ibotenic acid is a non-proteinogenic alpha-amino acid. It has a role as a neurotoxin.
(RS)-ibotenic acid has been reported in Amanita gemmata, Amanita pseudosychnopyramis, and other organisms with data available.
Ibotenic acid is a chemical compound that is naturally occurring in the mushrooms Amanita muscaria and Amanita pantherina, among others. Ibotenic acid is a powerful neurotoxin that is used as a brain-lesioning agent and has shown to be highly neurotoxic when injected directly into the brains of mice and rats. In 1960's, ibotenic acid was originally isolated from Amanita ibotengutake in Japan. A. ibotengutake is very like to A. pantherina. (L1141)
A neurotoxic isoxazole (similar to KAINIC ACID and MUSCIMOL) found in AMANITA mushrooms. It causes motor depression, ataxia, and changes in mood, perceptions and feelings, and is a potent excitatory amino acid agonist.
Recognized use
Ibotenic acid is used as a brain lesioning agent in the medical environment. When injected intracranially, ibotenic acid causes the development of lesions of the brain. (L1141)
History, discovery and cultural use
— Not in this archive. PubChem, ChEMBL and the Human Protein Atlas publish pharmacology, regulation and toxicology, and none of them publishes a heading for when Ibotenic acid was first made, by whom, or how it has been used. That is a gap in the databases this site reads and not a gap in the literature — the history of these compounds is written, at length and under peer review, in the works below. This site does not summarize them; it says where they are. Where a published passage above happens to touch origin or traditional use, it appears inside the entry that carries it.
Histories of this field
Scholarship on psychedelics generally, not on Ibotenic acid specifically. Whether any of these treats this compound is a question for the book, not for this page.
Mescaline: A Global History of the First Psychedelic
Traces mescaline and the peyote and San Pedro cacti from pre-Columbian ritual use through nineteenth-century chemistry to twentieth-century psychiatry and the counterculture.
Jay M. Mescaline: A Global History of the First Psychedelic. Yale University Press, New Haven and London; 2019. ISBN 9780300231076.
Expanding Mindscapes: A Global History of Psychedelicsopen access
Essays on the international and cross-cultural history of psychedelic science, deliberately decentring the standard North American and European account.
Dyck E, Elcock C, editors. Expanding Mindscapes: A Global History of Psychedelics. The MIT Press, Cambridge MA; 2023. ISBN 9780262546935 (paper), 9780262376891 (open access). doi:10.7551/mitpress/14417.001.0001.
Plants of the Gods: Their Sacred, Healing, and Hallucinogenic Powers
Botany, ethnography and chemistry of the principal hallucinogenic plants, by the founder of modern ethnobotany and the chemist who first synthesized LSD.
Schultes RE, Hofmann A, Rätsch C. Plants of the Gods: Their Sacred, Healing, and Hallucinogenic Powers. 2nd ed. Healing Arts Press, Rochester VT; 2001. ISBN 9780892819799.
Psychonauts: Drugs and the Making of the Modern Mind
The tradition of scientific self-experimentation with psychoactive drugs, and its part in the emergence of psychology and of modernism.
Jay M. Psychonauts: Drugs and the Making of the Modern Mind. Yale University Press, New Haven; 2023. ISBN 9780300257946.
Ancient Psychoactive Substances
Archaeological and bioarchaeological evidence for psychoactive plant use across the ancient world.
Fitzpatrick SM, editor. Ancient Psychoactive Substances. University Press of Florida, Gainesville; 2018. ISBN 9780813056708.
A chapter tracing psychedelic and entactogen research from earlier ritual use through the mid-century research period to current clinical trials.
Stroud C, Posey Norris SM, Matney C, editors. History and Current Status of Psychedelics and Entactogens for the Treatment of Psychiatric Disorders. In: Exploring Psychedelics and Entactogens as Treatments for Psychiatric Disorders: Proceedings of a Workshop. National Academies Press, Washington DC; 2022. NBK587225.
Workshop proceedings record what participants said; they are not a consensus statement of the National Academies.
Peer-reviewed review covering the isolation, synthesis, pharmacology and ritual use of peyote and mescaline.
Dinis-Oliveira RJ, Pereira CL, da Silva DD. Pharmacokinetic and Pharmacodynamic Aspects of Peyote and Mescaline: Clinical and Forensic Repercussions. Current Molecular Pharmacology 12(3):184–194; 2019. doi:10.2174/1874467211666181010154139.
Institutional archives
- Heffter Research Institute Funds and coordinates clinical research on psilocybin, and keeps records of the studies it has supported since 1993. Sponsors the research it archives.
- Multidisciplinary Association for Psychedelic Studies (MAPS) Sponsors clinical research, chiefly on MDMA-assisted therapy, and publishes an archive of historical and contemporary documents. A sponsor and an advocacy organization, not a disinterested archive; its clinical programme has a commercial arm.
The rest of this dossier
- Affinity — 6 measurements in this archive, equilibrium constants kept apart from functional readouts.
- Toxicology — 1 published passage, plus any assay in this archive bearing on toxicity.
- Legal — listed by the DEA among its drugs of concern, with no schedule stated in the record held here.
Passages via PubChem descriptive sections, aggregating DrugBank, LiverTox, FDA, DEA, HSDB, EPA. Each is quoted whole and attributed to the database that published it. The only prose written here about Ibotenic acid is the history note, which says so on its face and carries a reference for every claim in it.
II · Identity
Structure and descriptors
Descriptors are computed here with RDKit from the structure PubChem returns — not from the archive's stored copy, so an edited local structure cannot reach this table.
- Formula
- C5H6N2O4R
- Molecular weight
- 158.11g/molR
- Exact mass
- 158.0328DaR
- cLogP
- -0.95R
- TPSA
- 109.3ŲR
- H-bond donors
- 3R
- H-bond acceptors
- 4R
- Rotatable bonds
- 2R
- Aromatic rings
- 1R
- Heavy atoms
- 11R
- Fraction sp³
- 0.200R
- Formal charge
- 0R
Computed with RDKit 2025.09.2 from the SMILES returned by PubChem. Audit run 26/09/2026.
III · Behavior
Behavioral summary
Class, mechanism, and the duration of acute effects — each quoted from the record or trial that publishes it. Duration of effects and plasma half-life are shown separately, because they are different quantities and diverge by a factor of three or four.
Classification
Duration of acute subjective effects
—
No controlled human trial reporting a duration for this compound is cited here. The archive does hold onset and duration ranges for it, inherited from an earlier build, but their source column is empty and so they cannot be shown. A duration is not inferred from a chemical relative.
Plasma elimination half-life
How fast the body clears the drug — not how long the effects last. The two diverge sharply: LSD is cleared with a half-life of about 2.6 h while its subjective effects run 8–12 h.
No half-life is published for this compound in the sources this site reads.
Primary pharmacological drivers
ChEMBL holds no curated mechanism-of-action record for this compound. The measured affinities below are the evidence this archive has for what it binds.
IV · Clinical
Clinical description
Where this compound's substance class sits in ICD-11 and DSM-5-TR, and how much of the recorded literature speaks to each domain of a mental status examination.
No diagnostic chapter is shown for this compound. Either PubChem records no MeSH pharmacological class for it, or the class it records is not one of the substance classes ICD-11 gives a chapter to. Inferring a chapter from the compound’s name or its binding profile would be a diagnosis this archive is in no position to make.
How much has been written about each domain
The clinical domains, and how many of the records this archive holds for this compound say something under each. What the terms mean, and the word list behind every spoke, are set out in the method.
None of the 1 records this archive holds for this compound uses a term from any of the clinical domains. That is a statement about the literature recorded here, not about the compound.
VI · Profile
Affinity rosette
The strongest measurement at each of 2 molecular targets. Cell-line and whole-organism screens are excluded here — they carry no affinity — and appear in the table below.
VII · Toxicology
Toxicological profile
What has been measured, and what has been published — kept apart, and neither scored. There is no risk rating on this page; the archive once carried one, identical for every compound, produced by a stub.
Measured in this archive
Assays that bear on toxicity, drawn from the same ChEMBL records as everything else on this page. They are measurements of what a compound binds or does to cells — not verdicts about what it does to a person.
No hERG, cytochrome, cytotoxicity or transport measurement exists for Ibotenic acid in this archive.
As published
Quoted verbatim from the database named after each passage, never summarized — a summary of a toxicology statement is a new claim.
Toxicity Summary
A portion of ibotenic acid is metabolized to muscimol, a potent GABAA agonist, activating the receptor for the brain's major inhibitory neurotransmitter, GABA. Muscimol actually binds to the same binding site on the GABAA receptor complex as GABA itself, as opposed to other GABAergic drugs such as barbiturates and benzodiazepines which bind to separate regulatory sites. GABAA receptors are widely distributed in the b…
Published passages via PubChem toxicology sections, aggregating Hazardous Substances Data Bank (HSDB), RTECS, LiverTox. No figure on this page is scored, ranked or combined into a risk level.
VIII · Evidence
Every measurement
One row per published value. The identifier in the last column resolves to the ChEMBL assay record it was read from.
Equilibrium binding constants 4
Ki and Kd — a concentration at equilibrium. Directly comparable across rows at the same target.
| Target | Class | Type | Value (nM) | pX | Organism | Assay |
|---|---|---|---|---|---|---|
| mGluR2, mGluR3 | Unclassified | Ki | 89.00 | 7.05 | RAT | PMID 9832156 |
| mGluR5 | Unclassified | Ki | 1,900 | 5.72 | HUMAN | PMID 11080213 |
| mGluR5 | Unclassified | Ki | 2,000 | 5.70 | HUMAN | PMID 9131252 |
| mGluR5 | Unclassified | Ki | 2,870 | 5.54 | PORCINE | PMID 7751958 |
Functional readouts 2
IC₅₀, EC₅₀, AC₅₀ and potency. Assay-dependent, and not interchangeable with a binding constant.
| Target | Class | Type | Value (nM) | pX | Organism | Assay |
|---|---|---|---|---|---|---|
| NMDA | Glutamate receptors | IC50 | 10,000 | 5.00 | Rattus norvegicus | CHEMBL748107 |
| Glutamate receptor ionotropic, AMPA | Glutamate receptors | IC50 | 76,000 | 4.12 | Rattus norvegicus | CHEMBL697796 |
- P
- PubChem
- C
- ChEMBL
- R
- Computed here with RDKit
- D
- Derived here from the stored measurement
IX · Trials
Registered clinical trials
Studies filed with ClinicalTrials.gov that name this compound as an intervention. A registered trial is a protocol, not a result — status and enrollment are printed beside every row, and withdrawn studies are counted rather than hidden.
— No registered study names Ibotenic acid as an intervention. That is an absence of registered research, not evidence about the compound. Most of this archive has never been the subject of a registered trial.
Records from ClinicalTrials.gov (U.S. National Library of Medicine, NIH), API v2. A study is listed against a compound only when a verified name for that compound appears as a whole word in one of the study's own intervention names. A short code must appear as written, and a name the registry uses for something else (Aleph, a vaccine maker) is not matched. Title matches are not accepted. The matched name and the intervention text it matched are shown with every row.
Searched as Ibotenic acid · DL-Ibotenic acid · (RS)-Ibotenic acid. Run this search at the registry.
A registered trial is a protocol somebody filed with the registry. It is not a result, and nothing on this plate says whether Ibotenic acid worked.
X · Legal
Controlled-substance status
United States federal scheduling, read from the DEA records this archive holds and shown with the passage each was read from. Not legal advice, and not necessarily current.
- DEA class
- Hallucinogens
- Added
- October 1998
As the DEA states it
Quoted whole. The badge above is a reading of these passages and adds nothing to them.
Amanita Muscaria (Class: Hallucinogens, Added Date: 10-1998)
United States federal status only. State law differs, and so does the law of every other country — none of it is represented here. Scheduling changes, and this reflects the DEA records held by PubChem descriptive sections when the monograph was last harvested, not necessarily today. This is a record of what a database publishes, not legal advice.
XI · Literature
Sources behind this dossier
The papers this compound's values were read from, ranked by what each contributed. Not a review of the field.
Every paper below is one some value on this page came from — a binding constant, a passage of pharmacology or toxicology, or a measured duration. Each entry says what this archive took from it. Nothing else is claimed about any of them: the title is the study’s own account of itself, and a summary written here would be an assertion with no source behind it.
- 01
Mutel V, Ellis GJ, Adam G et al. · Journal of neurochemistry 2000
- · 1 measurement at 1 target (Ki), strongest mGluR5 at 5.72 pX
- 02
Characterization of (2S,2'R,3'R)-2-(2',3'-[3H]-dicarboxycyclopropyl)glycine binding in rat brain
Mutel V, Adam G, Chaboz S et al. · Journal of neurochemistry 1998
- · 1 measurement at 1 target (Ki), strongest mGluR2, mGluR3 at 7.05 pX
- 03
Pharmacology and functions of metabotropic glutamate receptors
Conn PJ, Pin JP · Annual review of pharmacology and toxicology 1997
- · 1 measurement at 1 target (Ki), strongest mGluR5 at 5.70 pX
- 04
Joly C, Gomeza J, Brabet I et al. · The Journal of neuroscience : the official journal of the Society for Neuroscience 1995
- · 1 measurement at 1 target (Ki), strongest mGluR5 at 5.54 pX