Corynantheine (Corynanthe Indole Alkaloid · Informational)

Compound	Corynantheine
Chemical class	Alkaloid — Indole (corynanthe-type monoterpenoid indole alkaloid)
CAS	1256-93-3
Primary source	Pausinystalia johimbe / Corynanthe spp. (yohimbe bark), minor alkaloid
Key applications	Structural-class reference; minor yohimbe co-alkaloid; informational-only
Claim strength	Emerging
Typical form	Research reference alkaloid; not offered as a supplement ingredient
Buy from Herbuno	Informational reference — see HerbIQ Compound Index →

Name origin: Corynantheine takes its name from the genus Corynanthe (Rubiaceae) and gives its name in turn to the corynanthe structural class — one of the foundational scaffolds of the monoterpenoid indole alkaloids. Its constitution was established in the early 1950s, and the class it defines encompasses yohimbine, the Rauvolfia heteroyohimbines, and the kratom alkaloids. Traditional use: Corynantheine has no independent traditional identity. It occurs as a minor alkaloid in yohimbe bark (Pausinystalia johimbe, formerly Corynanthe johimbe), a West and Central African tree whose bark has been used in traditional practice as a tonic and reputed aphrodisiac and which is now widely, and contentiously, sold as a dietary supplement. The bark's reputation rests on yohimbine, not on corynantheine. Research trajectory: Corynantheine is chiefly significant as the structural parent of the corynantheine-type alkaloids, a group that includes major constituents of Mitragyna speciosa (kratom) such as corynantheidine; a catalytic asymmetric synthesis platform now provides access to the indole, spirooxindole, and pseudoindoxyl series of this class, enabling systematic biological investigation Sun 2024. As an individual compound, however, corynantheine is listed by European regulators among the yohimbe bark constituents whose properties remain undefined, a point that itself contributed to the difficulty of assessing yohimbe's safety EFSA 2013. Commercial source: Corynantheine is a research reference alkaloid; Herbuno does not offer it as an isolated ingredient, and it is included here for chemical-family completeness.

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Evidence for Corynantheine Applications

Structural-class parent: Corynantheine defines the corynantheine-type corynanthe alkaloids, and a catalytic asymmetric platform has been developed that provides access to all series of this class — indole, spirooxindole, and pseudoindoxyl — including the first enantioselective total synthesis of corynantheidine pseudoindoxyl, opening the class to comprehensive biological investigation Sun 2024. Claim strength: Emerging.

Minor yohimbe constituent: Corynantheine occurs alongside yohimbine, corynanthine, ajmalicine, and dihydrocorynantheine in yohimbe bark; European regulatory assessment of yohimbe explicitly lists these co-occurring alkaloids while noting that their individual properties are largely undefined, which was one of the factors complicating a risk-benefit assessment of the bark EFSA 2013. Claim strength: Emerging.

Relationship to the kratom alkaloids: The corynantheine skeleton underlies major Mitragyna speciosa constituents, so understanding this scaffold is directly relevant to the pharmacology of the corynanthe alkaloids more broadly, including mitragynine and its congeners Sun 2024. Claim strength: Emerging.

No established standalone pharmacology: Unlike yohimbine, which is a well-characterised selective alpha-2 adrenoceptor antagonist, corynantheine has no defined individual pharmacological profile in the regulatory literature, and it should not be assumed to share yohimbine's activity EFSA 2013. Claim strength: Emerging.

Analytical relevance: Corynantheine is one of the alkaloids resolved when yohimbe bark is profiled chromatographically, and the variability of the total alkaloid profile between commercial bark samples is a recognised quality-control problem for yohimbe-derived material generally EFSA 2013. Claim strength: Emerging.

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Dosage & Formulator Specification

Corynantheine is a research reference alkaloid with no established human dosing and no commercial standardisation. It is not offered by Herbuno as an isolated ingredient, and no supplement-grade corynantheine material exists.

A specific sourcing caution applies here. Yohimbe bark extracts do contain corynantheine as a minor co-alkaloid, but those products are yohimbine-bearing bark preparations, not corynantheine-standardised material, and it would be an error to treat a yohimbe extract as a corynantheine ingredient. The two are not interchangeable: yohimbine dominates the bark's alkaloid content and its pharmacology, while corynantheine is a trace constituent of undefined activity.

Yohimbe itself is a botanical under significant regulatory scrutiny. European assessment rejected its therapeutic use for sexual dysfunction and fatigue on grounds of inadequate evidence and an inability to complete a risk-benefit assessment, and the recognised risks of its main alkaloid yohimbine include hypertension, tachycardia, tremor, anxiety, and insomnia. Compounding this, yohimbine content varies widely and unpredictably between commercial products, which is precisely why the undefined properties of the co-occurring alkaloids matter. Any formulator considering yohimbe-derived material must engage with that regulatory and quality reality rather than with corynantheine in isolation.

The wider lesson of corynantheine is about how alkaloid families are organised. Yohimbe bark, Rauvolfia root, and kratom leaf are botanically unrelated and used for entirely different purposes, yet all three draw on the same corynanthe scaffold, because the monoterpenoid indole alkaloids are built from a shared strictosidine-derived pathway that surfaces across many plant families. Recognising that a compound belongs to a structural class tells you where to look for its relatives, but it does not tell you what any individual member does — corynantheine and yohimbine sit on the same skeleton and behave quite differently. That distinction between scaffold and activity is worth holding onto whenever a minor alkaloid is described by reference to a better-known relative.

This monograph documents corynantheine as a chemical-family reference within the HerbIQ index, connecting the corynanthe scaffold to yohimbine, the Rauvolfia heteroyohimbines, and the kratom alkaloids covered elsewhere, and is explicitly not a sourcing recommendation.

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Frequently Asked Questions — Corynantheine

What is corynantheine?
Corynantheine is a corynanthe-type monoterpenoid indole alkaloid found as a minor constituent of yohimbe bark (Pausinystalia johimbe / Corynanthe johimbe) and related Rubiaceae. It gives its name to the corynanthe structural class, which also encompasses the kratom alkaloids and yohimbine itself.

Is corynantheine the same as yohimbine?
No. Yohimbine is the dominant, pharmacologically characterised alkaloid of yohimbe bark and a selective alpha-2 adrenoceptor antagonist. Corynantheine is a distinct, minor co-occurring alkaloid whose individual properties are, in the assessment of European regulators, essentially undefined.

Why is corynantheine informational-only?
It is a trace bark alkaloid with no established standalone pharmacology and no commercial standardisation, and it occurs in yohimbe, a botanical subject to significant regulatory scrutiny. Herbuno does not offer it as an isolated ingredient, and this page is a chemical-family reference.

Why does the corynanthe class matter?
The corynanthe skeleton is one of the foundational scaffolds of the monoterpenoid indole alkaloids, underlying yohimbine, the Rauvolfia heteroyohimbines, and the kratom alkaloids including mitragynine. Corynantheine-type alkaloids are therefore a major target of synthetic chemistry aimed at exploring this pharmacologically rich family.

Related compounds: Yohimbine, Mitragynine, Rauwolscine, Reserpine

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Claim-strength scale – High = multiple human RCTs; Moderate = limited trials or strong preclinical convergence; Emerging = early-stage lab or animal data.

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