Skip to content

Batch information on every product pageTHC < 0.3%Shipped from France10% off when you sign up

From the plant

THCA-BΔ9-tetrahydrocannabinolic acid B

A rare THCA isomer carrying the carboxyl at position 4; no pharmacological data of its own.

Narcotic: generic clause
Level of detail

Harm-reduction warning

No characterised human dose: animal / in vitro data only. Effect profile, safety margin and acute toxicity are not documented in human clinical practice. Extremely potent compound: severe effects, seizures and deaths reported in the literature.

C₂₂H₃₀O₄

CID 46889976

Family
PhytocannabinoidMinor
Origin
Origin not established
Molar mass
358.50 g/mol

Updated on

In plain terms

THCA-B is a rare variant of the acid that precedes THC in cannabis: its acid group sits in a different place than in the usual form, THCA-A. It was isolated from hashish in 1969, and how it forms is still unknown. No study has measured its effects.

Receptors and activity

    Bar length follows the measured value (Ki, Kd, EC50 or IC50), on one scale shared by every entry, from 100 µM to 0.1 nM. A target with no cited value has no bar.

    Pharmacology

    THCA-B is the positional isomer of THCA-A: the carboxyl group sits at position 4 of the aromatic ring instead of position 2. Described in 1969 by Mechoulam et al. from a hashish sole, its crystal structure was solved in 1975 (Rosenqvist & Ottersen; Radwan 2021). Since THCA synthase is described as forming only THCA-A, no biochemical pathway explains its presence; Filer (2023) proposed a photochemical formation from THCA-A via CBDA, without experimental demonstration. No affinity, activity, pharmacokinetic or toxicology data have been published for this molecule. As the two acids differ only in the position of the carboxyl, loss of this group would lead to the same Δ9-THC; no decarboxylation study specific to THCA-B was found, however.

    Key sources.

    History

    Source
    Isolated from hashish; origin not established

    Biosynthetic pathway

    Origin not established. THCA synthase is described as forming only THCA-A, carboxylated at position 2; no biochemical pathway explains THCA-B. Filer (2023) proposed a photochemical mechanism, from THCA-A to CBDA and then to THCA-B; this hypothesis has not been tested experimentally.

    Classification

    Family, origin and source verification

    Family

    Phytocannabinoid › Minor

    Presence in the plant

    Present in the plant; origin not established

    Chemistry

    Type Δ9-THC · C5 side chain · acid form

    Verification

    Every fact on this entry was checked against its primary sources on 20 October 2026.

    Wikipedia (English)

    No dedicated article.

    References

    1. Mechoulam R, Ben-Zvi Z, Yagnitinsky B, Shani A. A new tetrahydrocannabinolic acid. Tetrahedron Lett 1969 (initial description) (new tab)PMID 5796587
    2. Rosenqvist E, Ottersen T. Crystal structure of THCA-B. Acta Chem Scand B 1975 (new tab)PMID 1138526
    3. Filer CN. Delta-9-Tetrahydrocannabinolic Acid B: A Mechanism for its Formation in Cannabis. Cannabis Cannabinoid Res 2023 (new tab)PMID 35290744
    4. Radwan et al. 2021, Molecules: inventory of cannabinoids, Δ9-THC type (new tab)PMID 34066753
    5. PubChem, CID 46889976 (identifiers and formula) (new tab)
    6. ANSM, consolidated list of narcotics (26/06/2026) (new tab)

    Identifiers

    Names

    Common name
    Δ9-tetrahydrocannabinolic acid B
    IUPAC name
    (6aR,10aR)-1-hydroxy-6,6,9-trimethyl-3-pentyl-6a,7,8,10a-tetrahydrobenzo[c]chromene-4-carboxylic acid
    Other names
    Δ9-THCA-B · 4-COOH-THCA · THCA B · 4-carboxy-Δ9-THC

    Identifiers

    Formula
    C₂₂H₃₀O₄
    PubChem CID
    46889976(new tab)
    InChIKey
    VITZNDKHSIWPSR-HZPDHXFCSA-N
    SMILES
    CCCCCC1=CC(=C2[C@@H]3C=C(CC[C@H]3C(OC2=C1C(=O)O)(C)C)C)O

    Machine-readable entry (JSON)

    LLM ingestion format: a structured superset of the entry (identifiers, binding, versioned legal status). Full corpus.