Paynantheine

Paynantheine is a monoterpenoid indole alkaloid with the molecular formula C23H28N2O4 that occurs naturally in the leaves of Mitragyna speciosa, where it is commonly reported as the second most abundant alkaloid after mitragynine.

Molecular formula: C₂₃H₂₈N₂O₄
Systematic name: Pending verification
Natural abundance: Second most abundant

What is Paynantheine?

Where does Paynantheine occur naturally?

Paynantheine occurs in the leaves of Mitragyna speciosa (kratom) and is frequently reported as the second most abundant alkaloid in the leaf alkaloid fraction, after mitragynine.

How is Paynantheine related to mitragynine?

Paynantheine and mitragynine are both monoterpenoid indole alkaloids from Mitragyna speciosa that share the same indole scaffold; Paynantheine has the molecular formula C23H28N2O4 and mitragynine has the molecular formula C23H30N2O4.

Structure and chemistry

Paynantheine shares the corynanthe indole scaffold of mitragynine and differs by an additional degree of unsaturation in the side chain, which is reflected in its molecular formula having two fewer hydrogen atoms.

It is grouped with the other Mitragyna alkaloids as a naturally occurring analogue that co-elutes with mitragynine in leaf extracts and is resolved by chromatographic analysis.

Paynantheine compared with related alkaloids

Comparison of Paynantheine with related Mitragyna alkaloids by molecular formula, systematic name, and natural abundance
Alkaloid	Molecular formula	Systematic name (IUPAC)	Natural abundance
Paynantheine	C₂₃H₂₈N₂O₄	Pending verification	Second most abundant
Mitragynine	C₂₃H₃₀N₂O₄	Pending verification	Predominant
Speciociliatine	C₂₃H₃₀N₂O₄	Pending verification	Minor
Speciogynine	C₂₃H₃₀N₂O₄	Pending verification	Minor

Sources

Quantification of major indole alkaloids in Mitragyna speciosa leaf (review)

Reviewed for scientific accuracy on 2026-07-15. This entry describes chemical structure and natural occurrence only.