Eburnamenine

Eburnamenine at a Glance

Eburnamenine is a pentacyclic monoterpenoid indole alkaloid (C₁₉H₂₂N₂, MW 278.4, CAS 517-30-6, PubChem CID 6857502) and one of the minor alkaloids of greater periwinkle (Vinca major) ^{2Reference 2Petzel-Witt S et al. · 2023Missed chances? Sequestration and non-sequestration of alkaloids by moths (Lepidoptera)View study →}. Structurally it is an N-vinylindole — the unsubstituted, fully aromatised parent of the group of alkaloids chemists call the eburnane or eburnamine–vincamine series ^{1,9Reference 1Bartlett MF · 1960The alkaloids of Hunteria eburneaView study →Reference 9Lounasmaa M · 1992ReviewEburnamine–vincamine alkaloids — reviewView study →}.

That parenthood is the whole point. Eburnamenine is not important because of what it does; it is important because of what is built on it. Vincamine is 14,15-dihydro-14β-hydroxy-eburnamenine-14-carboxylic acid methyl ester. The nootropic drug vinpocetine is eburnamenine-14-carboxylic acid ethyl ester. Eburnamonine (vinburnine) is the N-acyl relative. Every one of those names is a modification of this skeleton — which is why “eburnamenine” appears in hundreds of chemical names and almost never as a subject in its own right.

Its own research record is close to empty, and that is stated rather than borrowing. A PubMed search for “eburnamenine” returns 29 records in total (checked July 2026). Twenty-two of them use the word only inside the systematic name of a derivative — vincamine, vinpocetine, vindeburnol, VA-045, AF 698. Six are phytochemical isolation reports that list it among known alkaloids. One put the free alkaloid into an assay, and that assay was a molecular-docking simulation in which eburnamenine was not among the promising hits ^{8Reference 8Naaz H et al. · 2013Anti-cholinergic alkaloids as potential therapeutic agents for Alzheimer’s disease: an in silico approachView study →}. There is no in-vivo work, no pharmacokinetics, no toxicology and no clinical data for the isolate.

Not a Chemotherapy Vinca Alkaloid

Worth defusing immediately, because “periwinkle alkaloid” pulls in the wrong association. Eburnamenine has nothing to do with vinblastine or vincristine. Those are bisindole alkaloids from Catharanthus roseus (Madagascar periwinkle) — a different genus, a different structural class, and a completely different clinical story as cytotoxic tubulin-binding chemotherapy agents. Eburnamenine is a monomeric eburnane alkaloid from Vinca, with no reported cytotoxicity and no oncology literature of any kind. None of the Catharanthus pharmacology, and none of its toxicity, transfers here.

The Eburnane Skeleton & Its Better-Known Siblings

The eburnane alkaloids are a compact family within the monoterpenoid indole alkaloids of the Apocynaceae. Eburnamenine, eburnamine, isoeburnamine and eburnamonine are the four “common” members that tend to co-occur, and the rest of the series is built by decorating one of them ^{4Reference 4Chong KW et al. · 2017Biosynthetic enantiodivergence in the eburnane alkaloids from KopsiaView study →}.

Bartlett and Taylor established the relationships in 1960 while working out the structures from Hunteria eburnea: eburnamine and isoeburnamine are diastereoisomeric carbinolamines that dehydrate under mild acid to give eburnamenine, the N-vinylindole, and oxidise to eburnamonine, the N-acyl lactam ^{1Reference 1Bartlett MF · 1960The alkaloids of Hunteria eburneaView study →}. Eburnamenine is therefore the most reduced-nitrogen, least-oxygenated member of the set — the bare skeleton.

Molecule	Relationship to the eburnane skeleton	Why it is known
Eburnamenine	The parent N-vinylindole; C19H22N2, no oxygen	Structural reference point — essentially no pharmacology of its own
Eburnamine / isoeburnamine	C-14 carbinolamines; dehydrate to eburnamenine under acid 1Reference 1Bartlett MF · 1960The alkaloids of Hunteria eburneaView study →	Co-isolated congeners; the compounds Bartlett & Taylor named the group from
Eburnamonine (vinburnine)	N-acyl lactam of the same skeleton	Antihypoxic / neuroprotective member of the class; used as a comparator drug 3,12Reference 3Vas A · 2005ReviewEburnamine derivatives and the brain — reviewView study →Reference 12Barzaghi F et al. · 1986A comparison of some of the pharmacological properties of the new eburnamenine derivative vindeburnol with those of vincamine, vinburnine, dihydroergotoxine mesilate and nicergolineView study →
Vincamine	14,15-dihydro-14β-hydroxy-eburnamenine-14-carboxylic acid methyl ester	The cerebral-blood-flow alkaloid; the one with human trials
Apovincamine	Dehydration product of vincamine — an eburnamenine-14-carboxylic acid ester	The direct precursor of the vinpocetine scaffold
Vinpocetine	Eburnamenine-14-carboxylic acid ethyl ester (ethyl apovincaminate)	The marketed nootropic; PDE1 inhibitor 10,11Reference 10National Toxicology Program · 2020AnimalNTP developmental and reproductive toxicity technical report on the prenatal development studies of vinpocetine (CASRN 42971-09-5) in Sprague Dawley rats and New Zealand White rabbits (gavage studies): DART Report 03. https://pubmed.ncbi.nlm.nih.gov/32716616/View study →Reference 11Hagiwara M et al. · 1984Effects of vinpocetine on cyclic nucleotide metabolism in vascular smooth muscleView study →
Vindeburnol (RU 24722), VA-045, AF 698	Synthetic eburnamenine derivatives	Research compounds from the 1980s–90s cerebral-insufficiency programmes 12,13,14Reference 12Barzaghi F et al. · 1986A comparison of some of the pharmacological properties of the new eburnamenine derivative vindeburnol with those of vincamine, vinburnine, dihydroergotoxine mesilate and nicergolineView study →Reference 13Tang YP et al. · 1997AnimalEffects of VA-045 on learning and memory deficits in traumatic brain injury (TBI)-induced retrograde and anterograde amnesic miceView study →Reference 14Marzo A et al. · 1982A new phthalidyl derivative of apovincaminic acid: (3α,16α)-eburnamenine-14 carboxylic acid phthalidyl ester (AF 698)View study →

A class profile exists — but it is a profile of the derivatives. Vas and Gulyás’s review of eburnamine derivatives describes vincamine, vinburnine, vindeburnol, apovincaminate and vinpocetine as sharing modulatory effects on cerebral circulation and neuronal homeostasis, with antihypoxic and neuroprotective potency “to various degrees” ^{3Reference 3Vas A · 2005ReviewEburnamine derivatives and the brain — reviewView study →}. Eburnamenine itself is not among the compounds that review characterises. Nothing here assumes the family profile extends to the parent skeleton, because nobody has tested whether it does.

One consequence of the chemistry deserves stating plainly: eburnamenine’s status as an unambiguous natural product is not fully secure. Alkaloid isolation routinely involves acid, and eburnamine dehydrates to eburnamenine under exactly those conditions ^{1Reference 1Bartlett MF · 1960The alkaloids of Hunteria eburneaView study →} — so an unknown share of its reported occurrences may be isolation artefacts rather than compounds present in the living plant. The classical review literature on this group has raised the point; it has never been settled, and it is logged as an open question rather than asserted either way here.

What a Search for “Eburnamenine” Actually Returns

Because the central claim is an absence, here is the evidence for the absence, in full.

PubMed, all fields, “eburnamenine” — 29 records (searched via NCBI E-utilities, July 2026). Sorted by what they actually are:

What the record is	Count	Examples
The word appears only inside a derivative’s systematic name	22	Vincamine PK and cerebral-blood-flow papers; vinpocetine PDE1, bioavailability and NTP toxicology; vindeburnol/RU 24722; VA-045; AF 698 10,11,12,13,14,16Reference 10National Toxicology Program · 2020AnimalNTP developmental and reproductive toxicity technical report on the prenatal development studies of vinpocetine (CASRN 42971-09-5) in Sprague Dawley rats and New Zealand White rabbits (gavage studies): DART Report 03. https://pubmed.ncbi.nlm.nih.gov/32716616/View study →Reference 11Hagiwara M et al. · 1984Effects of vinpocetine on cyclic nucleotide metabolism in vascular smooth muscleView study →Reference 12Barzaghi F et al. · 1986A comparison of some of the pharmacological properties of the new eburnamenine derivative vindeburnol with those of vincamine, vinburnine, dihydroergotoxine mesilate and nicergolineView study →Reference 13Tang YP et al. · 1997AnimalEffects of VA-045 on learning and memory deficits in traumatic brain injury (TBI)-induced retrograde and anterograde amnesic miceView study →Reference 14Marzo A et al. · 1982A new phthalidyl derivative of apovincaminic acid: (3α,16α)-eburnamenine-14 carboxylic acid phthalidyl ester (AF 698)View study →Reference 16Vlase L et al. · 2005Pharmacokinetics and comparative bioavailability of two vinpocetine tablet formulations in healthy volunteers by using the metabolite apovincaminic acid as pharmacokinetic parameterView study →
Phytochemical isolation reports listing it among known alkaloids	6	Vinca major 2Reference 2Petzel-Witt S et al. · 2023Missed chances? Sequestration and non-sequestration of alkaloids by moths (Lepidoptera)View study →, Hunteria zeylanica 5Reference 5Liu Q et al. · 2016Two new indole alkaloids from Hunteria zeylanicaView study →, Leuconotis eugeniifolia 6Reference 6Tan YS et al. · 2024Quinoline, indole, and isogranatanine alkaloids from Malayan Leuconotis eugeniifoliaView study →, Comularia camerunensis 7Reference 7Bruneton J · 1982Alcaloïdes du Comularia camerunensisView study →, Kopsia spp. 4Reference 4Chong KW et al. · 2017Biosynthetic enantiodivergence in the eburnane alkaloids from KopsiaView study →
A bioassay or simulation involving the free alkaloid	1	An in-silico acetylcholinesterase docking study 8Reference 8Naaz H et al. · 2013Anti-cholinergic alkaloids as potential therapeutic agents for Alzheimer’s disease: an in silico approachView study →
Marketing-flavoured, not a study of the compound	1	A sports-nutrition piece on “eburnamenine-like indole structures” 17Reference 17Calvo F et al. · 2013E.L.I.S. (eburnamenine-like indole structures), extracted from medicinal plants, as performance catalysts in sportsView study →

Narrower searches confirm the shape rather than adding to it. eburnamenine AND (vasodilat* OR cytotox* OR antimicrob*) returns 8 records — all of them derivative papers or the Leuconotis isolation. eburnamenine AND (pharmacokinetic* OR toxicity) returns 7 — every one about vinpocetine, vindeburnol or vincamine. There is no record anywhere in that set of eburnamenine being dosed, assayed in cells, given to an animal, or measured in a body.

This is not a gap that further searching will close. It is the actual state of the literature.

What It's Used For

Nothing here is scoreable, and no evidence table is offered. Support scoring weights human evidence over animal over in-vitro; eburnamenine has none of the three. Publishing a ranked table with a single in-silico row would give a false impression of an evidence base, so the position is stated instead.

1. Acetylcholinesterase Docking (In Silico Only)

The only study in which the free alkaloid was examined for an activity. Naaz and colleagues docked thirteen plant-derived alkaloids against acetylcholinesterase, the target of the approved Alzheimer’s drugs, as a computational screen. Eburnamenine was included in the panel alongside eburnamine, eburnamonine and geissoschizol, all four drawn from Hunteria zeylanica ^{8Reference 8Naaz H et al. · 2013Anti-cholinergic alkaloids as potential therapeutic agents for Alzheimer’s disease: an in silico approachView study →}.

The compounds the study actually reported as promising were pleiocarpine and its amino derivative — which the authors modelled as better AChE inhibitors than tacrine or rivastigmine. Eburnamenine was not among the highlighted hits ^{8Reference 8Naaz H et al. · 2013Anti-cholinergic alkaloids as potential therapeutic agents for Alzheimer’s disease: an in silico approachView study →}.

This is worth reading as a mild negative rather than a lead. It also carries no isolate/plant distinction, because no physical material was involved: this was a docking simulation, not an experiment. It is nonetheless relevant context that Vinca major’s crude alkaloid fraction does show strong anticholinesterase activity in vitro — but that is a whole-fraction result on the periwinkle page with no identified active constituent, and it cannot be attributed to this molecule.

Gap: everything. No enzyme assay was run, no IC₅₀ exists, no cell or animal work followed, and the simulation’s own verdict on eburnamenine was unremarkable. A single Ellman assay on purified eburnamenine would be the cheapest meaningful experiment anyone could do on this compound, and it has not been done.

Mechanisms

No mechanism table is offered, because no target has been reported for eburnamenine. No receptor binding, enzyme inhibition, ion-channel or transporter interaction has been measured for the free alkaloid. The targets associated with this skeleton in the literature — calmodulin-dependent phosphodiesterase 1 (vinpocetine, IC₅₀ ≈ 21 µM against Ca²⁺-dependent PDE in rabbit aorta ^{11Reference 11Hagiwara M et al. · 1984Effects of vinpocetine on cyclic nucleotide metabolism in vascular smooth muscleView study →}), sodium and calcium channels, the peripheral benzodiazepine receptor and glutamate receptors ^{3Reference 3Vas A · 2005ReviewEburnamine derivatives and the brain — reviewView study →}, and GABA_A modulation by the nitrooxy ester VA-045 — are all properties of substituted derivatives carrying a C-14 ester or hydroxyl. Eburnamenine has neither. Attributing any of them to the parent hydrocarbon skeleton would be an unsupported inference.

Pharmacokinetics

None. Absorption, oral bioavailability, distribution, protein binding, metabolism, metabolites and half-life are all unstudied for eburnamenine.

The PK data that exist in this chemical space belong to other molecules and are noted only so they are not mistaken for this one: vinpocetine is so extensively first-pass metabolised that its plasma concentrations are too low to measure reliably, and bioequivalence work has to be run on the metabolite apovincaminic acid instead (C_max ≈ 50 ng/mL after a 10 mg dose) ^{16Reference 16Vlase L et al. · 2005Pharmacokinetics and comparative bioavailability of two vinpocetine tablet formulations in healthy volunteers by using the metabolite apovincaminic acid as pharmacokinetic parameterView study →}; vincamine reaches peak plasma levels around 90 minutes after an oral dose with a β-phase half-life near 2 hours. Neither figure describes eburnamenine, which — lacking the ester group that both of those molecules are hydrolysed at — would not be expected to share their disposition anyway.

Clinical Trials

None, at any stage. No registered trial has ever administered eburnamenine, and no animal study has either. The clinical record associated with this skeleton is entirely vincamine’s and vinpocetine’s, and belongs on those pages.

Last checked: July 2026.

Isolate vs. Plant Studies

This molecule has neither kind of evidence, which is an unusual and clarifying position to be in.

There is no isolate pharmacology. Eburnamenine has been isolated repeatedly — it is a routine find in eburnane-bearing Apocynaceae — but isolation has always been the endpoint. In the papers that report it, the compound is identified by NMR and MS comparison against published data and then set aside while the authors characterise whatever is new ^{4,5,6,7Reference 4Chong KW et al. · 2017Biosynthetic enantiodivergence in the eburnane alkaloids from KopsiaView study →Reference 5Liu Q et al. · 2016Two new indole alkaloids from Hunteria zeylanicaView study →Reference 6Tan YS et al. · 2024Quinoline, indole, and isogranatanine alkaloids from Malayan Leuconotis eugeniifoliaView study →Reference 7Bruneton J · 1982Alcaloïdes du Comularia camerunensisView study →}. The 2024 Leuconotis eugeniifolia study is typical: (+)-eburnamenine N-oxide was described as a new alkaloid, cytotoxicity screening was run on the panel, and the actives were two other compounds entirely ^{6Reference 6Tan YS et al. · 2024Quinoline, indole, and isogranatanine alkaloids from Malayan Leuconotis eugeniifoliaView study →}.

There is no plant-level evidence for it either. Vinca major’s own in-vitro signals — antioxidant, anticholinesterase, tyrosinase-inhibitory — are properties of crude alkaloid and methanolic extracts, with no active constituent identified, and the herb has no human data at all. So there is no whole-plant finding waiting to be attributed to eburnamenine, and no isolate finding to be qualified by a whole-plant caveat. The periwinkle page carries that extract-level evidence in full.

The transferable-evidence trap here runs sideways, not up. The temptation is not to read plant data onto the molecule but to read sibling data onto it — to treat eburnamenine as a cerebral vasodilator because vincamine is one, or as a PDE1 inhibitor because vinpocetine is one. Those relatives differ by the presence of a C-14 carboxylic ester, which is exactly the pharmacophore the derivative literature turns on ^{3,10,11Reference 3Vas A · 2005ReviewEburnamine derivatives and the brain — reviewView study →Reference 10National Toxicology Program · 2020AnimalNTP developmental and reproductive toxicity technical report on the prenatal development studies of vinpocetine (CASRN 42971-09-5) in Sprague Dawley rats and New Zealand White rabbits (gavage studies): DART Report 03. https://pubmed.ncbi.nlm.nih.gov/32716616/View study →Reference 11Hagiwara M et al. · 1984Effects of vinpocetine on cyclic nucleotide metabolism in vascular smooth muscleView study →}. The skeleton they share is a starting point for chemistry, not a shared mechanism.

Prevalence in Nature

Eburnamenine occurs across the Apocynaceae, chiefly in the tribes that produce eburnane alkaloids. Every report is qualitative — no concentration, yield or percentage figure for this compound has been published for any plant.

Vinca major — the occurrence relevant to this database. Petzel-Witt and colleagues used eburnamenine as the marker alkaloid of Vinca major in a moth host-plant study: larvae of the oleander hawk moth (Daphnis nerii) were reared on the plant and analysed for sequestered alkaloids, and the moths were found unable to sequester eburnamenine from their host, unlike the garden tiger moth’s uptake of atropine from Atropa belladonna ^{2Reference 2Petzel-Witt S et al. · 2023Missed chances? Sequestration and non-sequestration of alkaloids by moths (Lepidoptera)View study →}. The plant-side detection is what confirms the compound’s presence in V. major; the moth-side result is an ecology finding, not a pharmacology one. Note that Vinca major alkaloid patterns are known to vary strongly with growing environment and chemotype, so presence in one population does not guarantee it elsewhere.

Hunteria eburnea — the type source. The West African tree from which Bartlett and Taylor isolated eburnamine, isoeburnamine, eburnamenine and eburnamonine in 1960, and from which the entire eburnane series takes its name ^{1Reference 1Bartlett MF · 1960The alkaloids of Hunteria eburneaView study →}.

Hunteria zeylanica — (−)-eburnamenine was isolated from Chinese (Hainan) material alongside eburnamine, (−)-eburnamonine and two new hydroxylated eburnamines ^{5Reference 5Liu Q et al. · 2016Two new indole alkaloids from Hunteria zeylanicaView study →}.

Kopsia and Leuconotis spp. — Malaysian Apocynaceae in which eburnamenine is one of the four “common eburnane alkaloids” used as the stereochemical reference point. Chong and colleagues showed these plants display biosynthetic enantiodivergence: in some species the common eburnanes including eburnamenine are isolated as racemic or scalemic mixtures while newer congeners are single enantiomers, and even the same species from Peninsular Malaysia and Malaysian Borneo shows different enantiomeric compositions ^{4Reference 4Chong KW et al. · 2017Biosynthetic enantiodivergence in the eburnane alkaloids from KopsiaView study →}. A (+)-eburnamenine N-oxide was later described as a new alkaloid from Leuconotis eugeniifolia stem bark ^{6Reference 6Tan YS et al. · 2024Quinoline, indole, and isogranatanine alkaloids from Malayan Leuconotis eugeniifoliaView study →}.

Comularia camerunensis — eburnamenine was among the known indole alkaloids obtained from stem and root bark, with pleiocarpine, pleiocarpinine, eburnamine and isoeburnamine ^{7Reference 7Bruneton J · 1982Alcaloïdes du Comularia camerunensisView study →}.

Not documented in Vinca minor under this name. The indexed literature places eburnamenine in V. major, not lesser periwinkle — which is the vincamine-rich species. That asymmetry is worth holding onto: the two Vinca species do not carry identical alkaloid profiles.

Discovery & Synthesis

First reported 1960. M. F. Bartlett and W. I. Taylor characterised eburnamenine in the first of their Alkaloids of Hunteria eburnea papers, which established the structures of eburnamine, isoeburnamine, eburnamenine and eburnamonine together and reported a synthesis of rac-eburnamonine ^{1Reference 1Bartlett MF · 1960The alkaloids of Hunteria eburneaView study →}. The names all derive from Hunteria eburnea Pichon, the species the alkaloids came from — and through it, from the ivory-white timber the epithet eburnea refers to. The compound was described from the outset as an N-vinylindole obtained by mild acid-catalysed dehydration of the eburnamine carbinolamines, which is both how its structure was proved and the reason its natural-product status is questionable (see above).

Synthesis. Eburnamenine is not the usual synthetic target of the series — eburnamonine is, and it has been made many times, including in modern four-step catalytic routes. Eburnamenine is more often encountered as a synthetic intermediate or a nomenclature root than as a product: the industrially important molecule built on this skeleton is vinpocetine, prepared by dehydrating and re-esterifying vincamine extracted from Vinca minor rather than by total synthesis ^{3,10Reference 3Vas A · 2005ReviewEburnamine derivatives and the brain — reviewView study →Reference 10National Toxicology Program · 2020AnimalNTP developmental and reproductive toxicity technical report on the prenatal development studies of vinpocetine (CASRN 42971-09-5) in Sprague Dawley rats and New Zealand White rabbits (gavage studies): DART Report 03. https://pubmed.ncbi.nlm.nih.gov/32716616/View study →}. The 1980s pharmaceutical programmes that produced vindeburnol, VA-045 and AF 698 all worked from the same semi-synthetic direction ^{12,13,14Reference 12Barzaghi F et al. · 1986A comparison of some of the pharmacological properties of the new eburnamenine derivative vindeburnol with those of vincamine, vinburnine, dihydroergotoxine mesilate and nicergolineView study →Reference 13Tang YP et al. · 1997AnimalEffects of VA-045 on learning and memory deficits in traumatic brain injury (TBI)-induced retrograde and anterograde amnesic miceView study →Reference 14Marzo A et al. · 1982A new phthalidyl derivative of apovincaminic acid: (3α,16α)-eburnamenine-14 carboxylic acid phthalidyl ester (AF 698)View study →}.

Manufacture today. None. Eburnamenine is not produced commercially, not sold as a supplement, and not routinely stocked as an analytical reference standard — which is part of why nobody has quantified it in any plant.

Patents: not yet researched.

Toxicity & Safety

The unknown grading is literal. No toxicology of any kind has been performed on eburnamenine — no acute or repeat-dose study, no genotoxicity assay, no reproductive or developmental data, no interaction work, no human exposure record. Its own citation record contains not a single toxicity endpoint. Absence of reported harm here reflects absence of testing.

Two contextual points, neither of which is a safety clearance:

The parent herb is flagged, and that flag stands regardless. Vinca major carries a moderate toxicity rating here on the strength of its indole-alkaloid content as a whole, with cautions about long-term use and about hypotension. Anyone’s real exposure to eburnamenine is via that plant, at unmeasured trace levels, so the relevant safety decision lives on the periwinkle page where intake is actually decided.

Sibling safety findings are real but do not transfer. They are recorded here so that a future pass does not mistake them for eburnamenine data. Vinpocetine — the eburnamenine ethyl ester — produced clear evidence of developmental toxicity in the NTP rat prenatal study, with increased post-implantation loss and ventricular septum defects in the absence of overt maternal toxicity ^{10Reference 10National Toxicology Program · 2020AnimalNTP developmental and reproductive toxicity technical report on the prenatal development studies of vinpocetine (CASRN 42971-09-5) in Sprague Dawley rats and New Zealand White rabbits (gavage studies): DART Report 03. https://pubmed.ncbi.nlm.nih.gov/32716616/View study →}. Vindeburnol, another eburnamenine derivative, is explicitly described in the literature as exhibiting hepatotoxic properties in man, and was used as the model hepatotoxicant in a rat in-vivo/in-vitro assay ^{15Reference 15Porquet D et al. · 1992In vitroEvaluation of the hepatotoxicological effects of a drug in an in vivo/in vitro modelView study →}. These findings belong to substituted derivatives, and neither extends them to the parent alkaloid nor treats the parent as cleared because they were found elsewhere.

Safety at a Glance

❔ Toxicity unknown

• Toxicity genuinely unknown. No acute, repeat-dose, genotoxicity, reproductive or interaction data exist for the isolated alkaloid. Untested is not the same as safe.
• No characterised human exposure. The compound is not sold, never dosed, and has never been quantified in any plant — so no exposure estimate can be made even for someone taking Vinca major.
• Two eburnamenine derivatives carry real safety findings — developmental toxicity for vinpocetine in rats ^{10Reference 10National Toxicology Program · 2020AnimalNTP developmental and reproductive toxicity technical report on the prenatal development studies of vinpocetine (CASRN 42971-09-5) in Sprague Dawley rats and New Zealand White rabbits (gavage studies): DART Report 03. https://pubmed.ncbi.nlm.nih.gov/32716616/View study →} and hepatotoxicity in man for vindeburnol ^{15Reference 15Porquet D et al. · 1992In vitroEvaluation of the hepatotoxicological effects of a drug in an in vivo/in vitro modelView study →}. Those are different molecules, but they show the skeleton is not inert once substituted.
• Do not read “periwinkle alkaloid” as chemotherapy. Vinblastine and vincristine are bisindoles from Catharanthus roseus; none of their toxicity applies here — and none of their activity does either.

Dosage

There is no dose, and no basis for setting one. Eburnamenine has never been administered to a person or an animal, has no pharmacokinetic data, and is not available as a product.

The doses commonly associated with this chemical family belong to different molecules and are listed only to be excluded: vincamine has been studied at 30 mg twice daily and vinpocetine at roughly 15–60 mg/day. Neither figure can be transferred to eburnamenine, which differs from both by the ester group that carries their activity. Human exposure to eburnamenine is incidental — trace amounts in Vinca major, a plant this database does not recommend as a self-administered simple in any case.

Nothing here is dosing guidance.

References

1. Bartlett MF, Taylor WI (1960). The alkaloids of Hunteria eburnea. I. The structures of eburnamine, isoeburnamine, eburnamenine and eburnamonine, and a synthesis of rac-eburnamonine. Journal of the American Chemical Society 82(22):5941–5946. https://doi.org/10.1021/ja01507a036
2. Petzel-Witt S, Wunder C, Pogoda W, Toennes SW, Mebs D (2023). Missed chances? Sequestration and non-sequestration of alkaloids by moths (Lepidoptera). Toxicon 227:107098. https://pubmed.ncbi.nlm.nih.gov/36990229/
3. Vas A, Gulyás B (2005). Eburnamine derivatives and the brain — review. Medicinal Research Reviews 25(6):737–757. https://pubmed.ncbi.nlm.nih.gov/16158388/
4. Chong KW, Yeap JS, Lim SH, Weber JF, Low YY, Kam TS (2017). Biosynthetic enantiodivergence in the eburnane alkaloids from Kopsia. Journal of Natural Products 80(11):3014–3024. https://pubmed.ncbi.nlm.nih.gov/29087707/
5. Liu Q, Chen CJ, Zhang L, Gao K (2016). Two new indole alkaloids from Hunteria zeylanica. Journal of Asian Natural Products Research 18(4):349–353. https://pubmed.ncbi.nlm.nih.gov/26667775/
6. Tan YS, Ng MP, Tan CH, Tang WK, Sim KS, Yong KT, Krishnan P, Lim KH, Lim SH, Low YY (2024). Quinoline, indole, and isogranatanine alkaloids from Malayan Leuconotis eugeniifolia. Journal of Natural Products 87(2):286–296. https://pubmed.ncbi.nlm.nih.gov/38284153/
7. Bruneton J (1982). Alcaloïdes du Comularia camerunensis. Planta Medica 46(1):58–59. https://pubmed.ncbi.nlm.nih.gov/17396943/
8. Naaz H, Singh S, Pandey VP, Singh P, Dwivedi UN (2013). Anti-cholinergic alkaloids as potential therapeutic agents for Alzheimer’s disease: an in silico approach. Indian Journal of Biochemistry & Biophysics 50(2):120–125. https://pubmed.ncbi.nlm.nih.gov/23720886/
9. Lounasmaa M, Tolvanen A (1992). Eburnamine–vincamine alkaloids — review. The Alkaloids: Chemistry and Pharmacology 41:1–116. https://doi.org/10.1016/S0099-9598(08)60059-0
10. National Toxicology Program (2020). NTP developmental and reproductive toxicity technical report on the prenatal development studies of vinpocetine (CASRN 42971-09-5) in Sprague Dawley rats and New Zealand White rabbits (gavage studies): DART Report 03. https://pubmed.ncbi.nlm.nih.gov/32716616/
11. Hagiwara M, Endo T, Hidaka H (1984). Effects of vinpocetine on cyclic nucleotide metabolism in vascular smooth muscle. Biochemical Pharmacology 33(3):453–457. https://pubmed.ncbi.nlm.nih.gov/6322804/
12. Barzaghi F, Dragonetti M, Formento ML, Gueniau C, Nencioni A, Mantegazza P (1986). A comparison of some of the pharmacological properties of the new eburnamenine derivative vindeburnol with those of vincamine, vinburnine, dihydroergotoxine mesilate and nicergoline. Arzneimittel-Forschung 36(10):1442–1448. https://pubmed.ncbi.nlm.nih.gov/3814205/
13. Tang YP, Noda Y, Hasegawa T, Nabeshima T (1997). Effects of VA-045 on learning and memory deficits in traumatic brain injury (TBI)-induced retrograde and anterograde amnesic mice. British Journal of Pharmacology 122(2):257–264. https://pubmed.ncbi.nlm.nih.gov/9313933/
14. Marzo A, Saccarello ML, Stradi R, Quadro E, Galzigna L, Tartarini S, Reali L (1982). A new phthalidyl derivative of apovincaminic acid: (3α,16α)-eburnamenine-14 carboxylic acid phthalidyl ester (AF 698). A preliminary report on its chemical and pharmacological properties. Arzneimittel-Forschung 32(6):601–603. https://pubmed.ncbi.nlm.nih.gov/7202363/
15. Porquet D, Appel M, Fournier T, Bertaux O, Biou D, Féger J (1992). Evaluation of the hepatotoxicological effects of a drug in an in vivo/in vitro model. Experientia 48(3):257–261. https://pubmed.ncbi.nlm.nih.gov/1372265/
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