mitragynine pseudoindoxyl Research Reference

Catalog classification, reference sizes, lab math links, and source-backed data. Educational use only — not medical advice.

Researched for: Vendor-neutral scientific reference catalog

Indole alkaloid; kratom-associated oxidative metabolite; atypical opioid receptor ligand compound Reference needs_revision Best effort · source review pending

Also known as: Mitragynine pseudoindoxyl, mitragynine-pseudoindoxyl, MP

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Best-effort research profile: this record has not passed full two-source scientific verification. Descriptive fields, research protocols, storage/handling notes, and interaction guidance below are shown with their evidence labels, but calculator presets and exact dosing math remain hidden until the record is verified or reaches Community-Supported status.

Quick Facts

Reference Sizes

Not standardized / source review pending

Best-Effort Research Profile

Mitragynine pseudoindoxyl is a corynanthe-type indole alkaloid with a spiro-pseudoindoxyl core. It has been reported as a microbial metabolite of mitragynine and as a downstream oxidative rearrangement product of 7-hydroxymitragynine. Research publications characterize it as a potent atypical opioid ligand with G-protein-biased μ-opioid receptor activity and limited or absent β-arrestin-2 recruitment in the reported assay systems. Recent structural work indicates that the compound can exist as a dynamic ensemble of stereoisomers in protic and physiologically relevant media.

Source review pending. This descriptive profile is shown from the available source material as a best-effort educational reference. It has not passed the full verification bar and is not a dosing instruction, medical claim, or treatment recommendation.

Research Profile

Onset

In mouse antinociception studies, peak effects were reported approximately 15 minutes after administration in one study and approximately 20 minutes after subcutaneous administration in a later study; timing was model- and protocol-dependent.

Administration Routes (Research)

Intracerebroventricular administration in mouse antinociception studiesSubcutaneous administration in mouse antinociception and safety-related studiesOral administration by gavage in mouse antinociception studies

Reported Research Effects

μ-opioid receptor agonism in in vitro functional assays
δ-opioid receptor antagonism reported in receptor and functional studies
G-protein-biased μ-opioid receptor signaling with no detectable β-arrestin-2 recruitment in the cited assay system
Naloxone-sensitive antinociceptive activity in rodent models
Preclinical studies reported slower development of antinociceptive tolerance than morphine under the tested regimen
Preclinical studies reported limited physical dependence, constipation, respiratory depression, reward, or aversion under specific tested conditions; these findings are not established as general human safety properties

Reflects preclinical/research literature context only. Not a medical claim, dosing instruction, or treatment recommendation.

Research Notes

Neutral preclinical reference data: in a 2016 mouse study, reported ED50 values for compound 3 included 0.38 micrograms by intracerebroventricular administration in the radiant-heat tail-flick assay, 0.76 mg/kg subcutaneously in the same assay, 7.5 mg/kg orally in the tail-flick assay, and 0.99 mg/kg in the hot-plate assay. A later metabolism study reported subcutaneous ED50 values of approximately 0.26 mg/kg in C57BL/6J mice and 0.30 mg/kg in 129Sv6 mice. These are animal-study values and are not human dosing recommendations. A 2023 synthesis and structural study reported gram-scale synthesis and demonstrated dynamic stereoisomerization in protic media.

Supplementary research context only. Not medical advice or a treatment recommendation.

Registry Identifiers

PubChem CID 44301701; CAS RN 2035457-43-1; FDA UNII BKA67VHE3B; molecular formula C23H30N2O5; molecular weight 414.5 g/mol; InChIKey BAEJBRCYKACTAA-WGUOAFTMSA-N; IUPAC name methyl (E)-2-[(2S,6'S,7'S,8'aS)-6'-ethyl-4-methoxy-3-oxospiro[1H-indole-2,1'-3,5,6,7,8,8a-hexahydro-2H-indolizine]-7'-yl]-3-methoxyprop-2-enoate

Source-Backed Observations

Mitragynine pseudoindoxyl is chemically and biologically labile in protic environments. A 2023 primary study reported rapid interconversion among stereoisomers under physiological-like conditions, with an equilibrium reached within approximately 20 minutes at 37 °C in Krebs–Ringer solution. Reported pharmacology is assay- and model-dependent; preclinical findings should not be interpreted as established human clinical effects.

Reflects published research. Educational reference — not a recommendation for use.

Sources Under Review

Mitragynine pseudoindoxyl | CID 44301701
https://pubchem.ncbi.nlm.nih.gov/compound/Mitragynine-pseudoindoxyl (accessed 2026-09-17)

UNII - BKA67VHE3B | MITRAGYNINE PSEUDOINDOXYL
https://precision.fda.gov/uniisearch/srs/unii/BKA67VHE3B (accessed 2026-09-17)

Mitragynine/Corynantheidine Pseudoindoxyls As Opioid Analgesics with Mu Agonism and Delta Antagonism, Which Do Not Recruit β-Arrestin-2
https://pubmed.ncbi.nlm.nih.gov/27556704/ (accessed 2026-09-17)

Mitragynine/Corynantheidine Pseudoindoxyls As Opioid Analgesics with Mu Agonism and Delta Antagonism, Which Do Not Recruit β-Arrestin-2
https://pmc.ncbi.nlm.nih.gov/articles/PMC5344672/ (accessed 2026-09-17)

Total Synthesis and Structural Plasticity of Kratom Pseudoindoxyl Metabolites
https://onlinelibrary.wiley.com/doi/full/10.1002/anie.202303700 (accessed 2026-09-17)

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Research Use Only. All content is for educational and research reference only. Not medical advice, a treatment recommendation, or guidance on human use. Compounds are not FDA-approved drugs unless specifically noted.