Cynaropicrin

Cynaropicrin at a Glance

Cynaropicrin is a guaianolide sesquiterpene lactone — a 5-7-5 tricyclic molecule with six stereocentres, four exocyclic double bonds and the reactive alpha-methylene-gamma-butyrolactone ring that defines its chemical family ^{1,2,10Reference 1Suchý M et al. · 1960On terpenesView study →Reference 2Corbella A et al. · 1972Absolute stereochemistry of cynaropicrin and related guaianolidesView study →Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →}. It was first characterised from globe artichoke in 1960 and is now treated as a chemotaxonomic marker for Cynara ^{1,10Reference 1Suchý M et al. · 1960On terpenesView study →Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →}.

Its defining property is taste. Cynaropicrin contributes roughly 80% of the characteristic bitterness of globe artichoke ^{3Reference 3Eljounaidi K et al. · 2015Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesisView study →} — which makes it, not the caffeoylquinic acids, the molecule behind artichoke’s classical role as a bitter. That matters, because the bitter-digestive action is one of the few herbal effects with a plausible receptor-level explanation: bitter taste is transduced by the TAS2R family, and sesquiterpene lactones of exactly this shape are established agonists at the SL-tuned receptor TAS2R46 ^{6,7,8Reference 6Brockhoff A et al. · 2007In vitroBroad tuning of the human bitter taste receptor hTAS2R46 to various sesquiterpene lactones, clerodane and labdane diterpenoids, strychnine, and denatonium — in vitro receptor assayView study →Reference 7Yanagisawa T · 2021In vitroCharacterization of the human bitter taste receptor response to sesquiterpene lactones from edible Asteraceae species and suppression of bitterness through pH control — in vitroView study →Reference 8Salamone S et al. · 2026In vitroDietary terpenoid lactones are promiscuous agonists of bitter taste receptors (TAS2Rs) — in vitroView study →}.

Everything else about the molecule is preclinical. It suppresses NF-kB signalling, kills trypanosomes in mice, blocks hepatitis-C entry in cell culture and protects keratinocytes from UVB — but almost all of it flows through the same non-selective mechanism (thiol alkylation), it has never been given to humans as an isolate, and its pharmacokinetics are essentially uncharacterised.

Three easily-confused artichoke molecules. Cynaropicrin is a sesquiterpene lactone. Cynarin is a caffeoylquinic acid (1,5-di-O-caffeoylquinic acid) and carries the choleretic/lipid story. Cynaroside is luteolin-7-O-glucoside, a flavonoid glycoside. They are three unrelated compounds routinely swapped for one another in writing about artichoke.

The Bitter Principle

Bitterness is not a side effect of cynaropicrin — it is the property the plant selected for, and the property that gave artichoke leaf its place in the materia medica.

How much of the bitterness it owns. Quantitative work in globe artichoke attributes ~80% of the plant’s characteristic bitter taste to cynaropicrin alone ^{3Reference 3Eljounaidi K et al. · 2015Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesisView study →}. It is the principal sesquiterpene lactone of the species, and its accumulation tracks the expression of the three biosynthetic genes (CcGAS, CcGAO, CcCOS) that build it ^{3,27Reference 3Eljounaidi K et al. · 2015Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesisView study →Reference 27Menin B et al. · 2012Genetic mapping and characterization of the globe artichoke (+)-germacrene A synthase gene, encoding the first dedicated enzyme for biosynthesis of the bitter sesquiterpene lactone cynaropicrinView study →}.

What makes it bitter. A sensory-panel structure-activity study on cynaropicrin and its close relative grosheimin, using both chemical derivatives and fungal bioconversion products, found that bitterness tracks molecular polarity — and that it is sharply abated either by removing the exomethylene groups or by opening the lactone ring ^{4Reference 4Cravotto G et al. · 2005Chemical and biological modification of cynaropicrin and grosheimin: a structure-bitterness relationship study — sensory panel evaluation of derivativesView study →}. A later QSAR analysis of the same derivative series reached the same conclusion quantitatively ^{5Reference 5Scotti L et al. · 2007Quantitative elucidation of the structure-bitterness relationship of cynaropicrin and grosheimin derivativesView study →}. In other words, the bitterness pharmacophore is the alpha-methylene-gamma-lactone — the same structural feature that makes the molecule a Michael acceptor.

The receptor. Human bitter taste runs through the ~25 TAS2R G-protein-coupled receptors. TAS2R46 was deorphanised in 2007 as a receptor broadly tuned to sesquiterpene lactones (alongside clerodane/labdane diterpenoids, strychnine and denatonium) ^{6Reference 6Brockhoff A et al. · 2007In vitroBroad tuning of the human bitter taste receptor hTAS2R46 to various sesquiterpene lactones, clerodane and labdane diterpenoids, strychnine, and denatonium — in vitro receptor assayView study →}. Later work confirmed that the sesquiterpene lactones of edible Asteraceae vegetables activate TAS2R46-expressing cells most strongly of any TAS2R, with EC50 values in the low micromolar range, and that the response is blunted by lowering pH ^{7Reference 7Yanagisawa T · 2021In vitroCharacterization of the human bitter taste receptor response to sesquiterpene lactones from edible Asteraceae species and suppression of bitterness through pH control — in vitroView study →}. A 2026 screen across the full human TAS2R panel established the lactone ring itself as a bitter chemotype that activates TAS2R46 and, depending on scaffold, other TAS2Rs as well ^{8Reference 8Salamone S et al. · 2026In vitroDietary terpenoid lactones are promiscuous agonists of bitter taste receptors (TAS2Rs) — in vitroView study →}.

An honest caveat on the receptor claim. Reviews routinely list “activation of bitter sensory receptors” among cynaropicrin’s pharmacology ^{10,11Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →Reference 11Yang CY et al. · 2026ReviewCynaropicrin: a promising sesquiterpene lactone with multifaceted therapeutic potential for various diseases — reviewView study →}, but the primary support for that is the sensory work above ^{4Reference 4Cravotto G et al. · 2005Chemical and biological modification of cynaropicrin and grosheimin: a structure-bitterness relationship study — sensory panel evaluation of derivativesView study →} plus the class-level receptor work ^{6,7,8Reference 6Brockhoff A et al. · 2007In vitroBroad tuning of the human bitter taste receptor hTAS2R46 to various sesquiterpene lactones, clerodane and labdane diterpenoids, strychnine, and denatonium — in vitro receptor assayView study →Reference 7Yanagisawa T · 2021In vitroCharacterization of the human bitter taste receptor response to sesquiterpene lactones from edible Asteraceae species and suppression of bitterness through pH control — in vitroView study →Reference 8Salamone S et al. · 2026In vitroDietary terpenoid lactones are promiscuous agonists of bitter taste receptors (TAS2Rs) — in vitroView study →} — not a published assay of cynaropicrin itself at a named TAS2R. The receptor assignment is a well-founded inference from a tightly matched chemotype, not a direct deorphanisation. Treat it as strong class evidence rather than a molecule-specific result.

What the bitter signal then does. In rats, oral artichoke leaf extract standardised to 1% cynaropicrin dose-dependently increased the volume of gastric juice and gastric mucus content and prevented ethanol- and stress-induced gastric mucosal injury; crucially, cynaropicrin alone at 1/100th of the extract dose reproduced the gastroprotection, while chlorogenic acid at its in-extract dose did not ^{9Reference 9Ishida K et al. · 2010AnimalEffects of artichoke leaf extract on acute gastric mucosal injury in ratsView study →}. The authors attributed the increased secretion to its “bitter stomachic character.” This is the closest thing to a mechanistic chain running from molecule to traditional use — and it is still a rodent study.

The Alpha-Methylene-Gamma-Lactone Warhead

Almost every claim made for cynaropicrin outside taste runs through one structural feature, and that feature is shared with hundreds of other sesquiterpene lactones.

The alpha-methylene-gamma-butyrolactone is an electrophilic Michael acceptor. It reacts with soft nucleophiles — chiefly cysteine thiols on proteins and on the free thiol pools (glutathione, trypanothione). Because NF-kB signalling, Keap1/Nrf2, tubulin, many kinases and much of redox metabolism all depend on reactive cysteines, an SL with this warhead will predictably: inhibit NF-kB, activate Nrf2, deplete glutathione, disturb the redox balance, and kill dividing cells. “Inhibits NF-kB in vitro” is therefore close to uninformative about which sesquiterpene lactone you are holding — parthenolide, costunolide, helenalin, lactucin and cynaropicrin all do it.

Cynaropicrin’s own structure-activity studies make this concrete. Nine synthetic derivatives showed that NF-kB inhibition depends on the side chain, the hydrophilicity of the OH-3 and OH-19 substituents and the C17-C18 exo-olefin ^{15Reference 15Li J et al. · 2019In vitroCynaropicrin and inhibition of NF-κB activation: a structure activity relationship study — in vitroView study →}; an antitrypanosomal SAR series found the acyl side chain at OH-8 essential for activity, with the same alpha-methylene-gamma-lactone required for both potency and cytotoxicity ^{14Reference 14Usuki T et al. · 2014In vitroAntitrypanosomal structure-activity-relationship study of synthetic cynaropicrin derivatives — in vitroView study →}. When a derivative was made less toxic, it also lost its antitrypanosomal activity ^{10,14Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →Reference 14Usuki T et al. · 2014In vitroAntitrypanosomal structure-activity-relationship study of synthetic cynaropicrin derivatives — in vitroView study →}. That is the signature of a reactive warhead rather than a selective ligand.

What is genuinely specific to cynaropicrin:

• Its bitterness and the ~80% share of artichoke’s taste ^{3,4Reference 3Eljounaidi K et al. · 2015Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesisView study →Reference 4Cravotto G et al. · 2005Chemical and biological modification of cynaropicrin and grosheimin: a structure-bitterness relationship study — sensory panel evaluation of derivativesView study →}.
• The direct demonstration that it depletes trypanothione and glutathione inside intact T. brucei cells within minutes, forming measurable GS-cynaropicrin and T(S-cynaropicrin)2 adducts — i.e. the Michael chemistry was actually observed, not assumed ^{13Reference 13Zimmermann S et al. · 2013In vitroCynaropicrin targets the trypanothione redox system in Trypanosoma brucei — in vitro mechanistic studyView study →}.
• Its identified high-affinity binding partners in macrophages — ATP/ADP translocase 2 and tubulin — pulled down from cell extract ^{16Reference 16Matsumoto T et al. · 2021In vitroInhibitory effects of cynaropicrin and related sesquiterpene lactones from leaves of artichoke (Cynara scolymus L.) on induction of iNOS in RAW264.7 cells and its high-affinity proteins — in vitroView study →}.
• Inhibition of SERCA, raising intracellular Ca2+ and ciliary beat frequency in human airway epithelial cells — an unusual target for an SL ^{40Reference 40Todo N et al. · 2024In vitroCynaropicrin increases intracellular Ca2+ and ciliary beat frequency in human airway epithelial cells by inhibiting SERCA — in vitroView study →}.
• Its in-vivo antitrypanosomal efficacy, which most SLs do not achieve ^{12Reference 12Zimmermann S et al. · 2012AnimalCynaropicrin: the first plant natural product with in vivo activity against Trypanosoma brucei — acute mouse modelView study →}.

Everything else on the anti-inflammatory and anticancer side should be read as class reactivity until a comparison against other SLs shows otherwise.

Leaf vs. Head: The Bitterness Axis in Breeding

Cynaropicrin is the reason the artichoke you eat and the artichoke leaf you take as medicine are chemically different plants.

Tissue. Cynaropicrin accumulates in leaves across developmental stages; in the receptacle it falls progressively as the inflorescence develops, and it is undetectable in the inflorescence bracts — the part you actually eat. Roots and inflorescence stems at commercial stage carry almost none ^{3Reference 3Eljounaidi K et al. · 2015Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesisView study →}. Within the leaf it is stored (and, from promoter evidence, synthesised) in the trichomes, not the apoplastic fluid ^{3Reference 3Eljounaidi K et al. · 2015Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesisView study →}. A three-cultivar field trial quantifying cynaropicrin in floral stems, receptacles and leaves reported it only for the leaves ^{28Reference 28Lombardo S et al. · 2022Improvement in the cynaropicrin, caffeoylquinic acid and flavonoid content of globe artichokes with gibberellic acid treatmentView study →}.

Cultivar and season. In that trial, leaf cynaropicrin ran 1.46-4.59 g/kg dry matter (~0.15-0.46% dry wt) depending on genotype and harvest time, with ‘Tema 2000’ at early-spring harvest more than three times ‘Tema 2000’ at mid-winter ^{28Reference 28Lombardo S et al. · 2022Improvement in the cynaropicrin, caffeoylquinic acid and flavonoid content of globe artichokes with gibberellic acid treatmentView study →}. An Alpine landrace, Carciofo di Malegno, came in at 0.52 mg/g (0.052% dry wt) — the lowest of the compared material, which the authors framed as an advantage for palatability ^{29Reference 29Zuccolo M et al. · 2025Phytochemical profiling of residual leaves from an Alpine landrace of globe artichoke (Cynara scolymus L.)View study →}. Commercial artichoke leaf extracts quantified by NMR ranged from not detectable to 1.6% ^{30Reference 30Pieri V · 2011Quantification of cynaropicrin in artichoke leaf extracts by 1H NMR spectroscopyView study →}.

Domestication has partly bred the bitterness out, and processing removes the rest. The edible head is the low-cynaropicrin organ by construction, and in cardoon — the same species grown for its stalks — the traditional practice of field blanching (excluding light for weeks) measurably reduces stalk cynaropicrin content, which is precisely why growers do it ^{31Reference 31Ceccanti C et al. · 2022Effect of blanching and boiling on the secondary metabolism of cultivated cardoon stalks: a case study of the Tuscany region (Italy)View study →}. Conversely, an agronomic treatment that raises leaf cynaropicrin (gibberellic acid) is pitched as a way to enrich the nutraceutical fraction of what is otherwise waste biomass ^{28Reference 28Lombardo S et al. · 2022Improvement in the cynaropicrin, caffeoylquinic acid and flavonoid content of globe artichokes with gibberellic acid treatmentView study →}.

The practical consequence for anyone reading a study: “artichoke” is not one exposure. A dinner-plate artichoke heart delivers essentially no cynaropicrin; a standardised leaf extract may deliver 0-1.6% of its mass as cynaropicrin depending on the product ^{30Reference 30Pieri V · 2011Quantification of cynaropicrin in artichoke leaf extracts by 1H NMR spectroscopyView study →}; and the trials that anchor artichoke’s clinical reputation (lipids, NAFLD, dyspepsia) used leaf extracts standardised on caffeoylquinic acids, not on cynaropicrin at all.

What It's Used For

Cynaropicrin has a large preclinical literature and no clinical one. The evidence splits into a taste/digestive story with a plausible mechanism, a genuinely notable antiparasitic isolate finding, and a broad in-vitro anti-inflammatory/anticancer body that is largely class reactivity.

Mechanisms

The load-bearing point: rows 2 through 8 are downstream of row 2. A molecule that alkylates cysteine will hit NF-kB, Nrf2, tubulin and redox metabolism whether or not those are its “real” targets — which is why selectivity, not potency, is the honest question for this compound.

Pharmacokinetics

This is the largest hole in the file. No published human or animal pharmacokinetic study of cynaropicrin — absorption, oral bioavailability, distribution, metabolism, half-life — could be located. What is known bears directly on whether the in-vitro numbers mean anything:

• It is chemically unstable outside a narrow window. Cynaropicrin is stable at 50 degrees C and pH 5 for at least 72 h, but degrades ~80% within 7 days at pH 8, giving deacylcynaropicrin as the major alkaline breakdown product; in soil it degrades completely within 7 days ^{39Reference 39Rosa D et al. · 2026Stability studies of cynaropicrin — the major sesquiterpene lactone of Cynara cardunculus leavesView study →}. Small-intestinal pH sits in exactly the alkaline range that destabilises it.
• It is water-soluble and Lipinski-compliant, which is why the 2016 review argued it was formulable — including as an injection, precisely because oral delivery was not demonstrated ^{10Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →}.
• It is consumed as a highly reactive electrophile. Any thiol-rich compartment — gastric mucus, the intestinal lumen, plasma glutathione, hepatic conjugation — is a sink. The reversal of its anti-inflammatory activity by added thiols ^{17Reference 17Cho JY et al. · 2000In vitroIn vitro anti-inflammatory effects of cynaropicrin, a sesquiterpene lactone, from Saussurea lappaView study →} is a laboratory demonstration of exactly the fate it would meet in vivo.
• Deacylation destroys activity. Removing the 2-hydroxymethyl-2-propenoyl side chain (the first thing alkaline hydrolysis does) cost ~10-fold antitrypanosomal potency and abolished toxicity to T. b. rhodesiense ^{10,12,14Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →Reference 12Zimmermann S et al. · 2012AnimalCynaropicrin: the first plant natural product with in vivo activity against Trypanosoma brucei — acute mouse modelView study →Reference 14Usuki T et al. · 2014In vitroAntitrypanosomal structure-activity-relationship study of synthetic cynaropicrin derivatives — in vitroView study →}.

The practical reading: cell-culture potencies of 1-10 uM should not be assumed to be reachable in human plasma after an oral dose. No number exists to check that against.

Clinical Trials

There are no clinical trials of isolated cynaropicrin — completed, recruiting or registered. The human evidence associated with this molecule belongs to standardised artichoke leaf extract, which is trialled and standardised on caffeoylquinic acids rather than on cynaropicrin, and in which cynaropicrin content ranges from not detectable to 1.6% ^{30Reference 30Pieri V · 2011Quantification of cynaropicrin in artichoke leaf extracts by 1H NMR spectroscopyView study →}. Its only routine human exposure is dietary (artichoke, cardoon, bitter aperitifs).

Last checked: July 2026.

Isolate vs. Plant Studies

Unusually for a plant constituent, almost all of cynaropicrin’s pharmacology is isolate work — and that is a strength and a trap at once.

The isolate record is real: pure cynaropicrin was the tested agent in the trypanosome screening and mouse model ^{12Reference 12Zimmermann S et al. · 2012AnimalCynaropicrin: the first plant natural product with in vivo activity against Trypanosoma brucei — acute mouse modelView study →}, the trypanothione-depletion mechanism ^{13Reference 13Zimmermann S et al. · 2013In vitroCynaropicrin targets the trypanothione redox system in Trypanosoma brucei — in vitro mechanistic studyView study →}, the derivative SAR series ^{14,15Reference 14Usuki T et al. · 2014In vitroAntitrypanosomal structure-activity-relationship study of synthetic cynaropicrin derivatives — in vitroView study →Reference 15Li J et al. · 2019In vitroCynaropicrin and inhibition of NF-κB activation: a structure activity relationship study — in vitroView study →}, the HCV entry assays ^{22Reference 22Elsebai MF et al. · 2016In vitroPan-genotypic hepatitis C virus inhibition by natural products derived from the wild Egyptian artichoke — in vitroView study →}, the keratinocyte AhR-Nrf2 work ^{21Reference 21Takei K et al. · 2015In vitroCynaropicrin attenuates UVB-induced oxidative stress via the AhR-Nrf2-Nqo1 pathway — in vitro, normal human keratinocytesView study →}, the guinea-pig ileum study ^{23Reference 23Emendörfer F et al. · 2005Antispasmodic activity of fractions and cynaropicrin from Cynara scolymus on guinea-pig ileum — isolated-tissue studyView study →} and the melanoma work ^{25Reference 25De Cicco P et al. · 2021In vitroInhibitory effects of cynaropicrin on human melanoma progression by targeting MAPK, NF-κB, and Nrf-2 signaling pathways in vitroView study →}. Several of these used cynaropicrin isolated from plants other than artichoke — Centaurea salmantica ^{12Reference 12Zimmermann S et al. · 2012AnimalCynaropicrin: the first plant natural product with in vivo activity against Trypanosoma brucei — acute mouse modelView study →}, Centaurea drabifolia ^{25Reference 25De Cicco P et al. · 2021In vitroInhibitory effects of cynaropicrin on human melanoma progression by targeting MAPK, NF-κB, and Nrf-2 signaling pathways in vitroView study →}, Saussurea lappa ^{17Reference 17Cho JY et al. · 2000In vitroIn vitro anti-inflammatory effects of cynaropicrin, a sesquiterpene lactone, from Saussurea lappaView study →}, Saussurea amara ^{26Reference 26Glasl S et al. · 2007AnimalCholeretic effects of the Mongolian medicinal plant Saussurea amara in the isolated perfused rat liverView study →} — which is good evidence that the effects belong to the molecule rather than a co-extracted artichoke component.

The trap is the direction of inference. Artichoke’s clinical reputation does not transfer to cynaropicrin. The randomised human evidence for artichoke — lipid lowering, NAFLD, functional dyspepsia — was generated with leaf extracts standardised on cynarin and total caffeoylquinic acids, in products whose cynaropicrin content is variable and sometimes zero ^{30Reference 30Pieri V · 2011Quantification of cynaropicrin in artichoke leaf extracts by 1H NMR spectroscopyView study →}. The one experiment that bridges the two properly is Ishida’s rat study, which deliberately compared the extract against its constituents at their in-extract doses and found cynaropicrin, not chlorogenic acid, carried the gastric effect ^{9Reference 9Ishida K et al. · 2010AnimalEffects of artichoke leaf extract on acute gastric mucosal injury in ratsView study →}. That is the model the rest of this literature needs and lacks.

Going the other way, cynaropicrin’s isolate potencies were mostly measured at concentrations no plausible oral dose of artichoke delivers. A 1-10 uM in-vitro effect and a leaf at 0.2% dry weight are not obviously the same phenomenon.

Prevalence in Nature

Cynaropicrin is an Asteraceae molecule, and within Asteraceae a marker of the thistle tribe.

Cynara. It is the principal sesquiterpene lactone of globe artichoke (Cynara cardunculus var. scolymus) and cardoon (C. cardunculus var. altilis), and is treated as a chemotaxonomic marker of the genus ^{10Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →}. Distribution within the plant is sharply tissue-specific: leaves accumulate it, the receptacle loses it during inflorescence development, and the edible bracts contain none detectable ^{3Reference 3Eljounaidi K et al. · 2015Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesisView study →}. Within the leaf it is concentrated in trichomes, where promoter analysis suggests it is both stored and made ^{3Reference 3Eljounaidi K et al. · 2015Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesisView study →}. Reported leaf levels run 0.15-0.46% dry weight across three Italian cultivars and two harvest dates ^{28Reference 28Lombardo S et al. · 2022Improvement in the cynaropicrin, caffeoylquinic acid and flavonoid content of globe artichokes with gibberellic acid treatmentView study →}, down to 0.052% in a low-bitterness Alpine landrace ^{29Reference 29Zuccolo M et al. · 2025Phytochemical profiling of residual leaves from an Alpine landrace of globe artichoke (Cynara scolymus L.)View study →}. The wild Egyptian artichoke (C. cardunculus var. sylvestris) is a documented source of the isolate ^{22Reference 22Elsebai MF et al. · 2016In vitroPan-genotypic hepatitis C virus inhibition by natural products derived from the wild Egyptian artichoke — in vitroView study →}.

Beyond Cynara. Cynaropicrin has been isolated across the wider Cardueae and related tribes: Centaurea (C. salmantica ^{12Reference 12Zimmermann S et al. · 2012AnimalCynaropicrin: the first plant natural product with in vivo activity against Trypanosoma brucei — acute mouse modelView study →}, C. drabifolia ^{25Reference 25De Cicco P et al. · 2021In vitroInhibitory effects of cynaropicrin on human melanoma progression by targeting MAPK, NF-κB, and Nrf-2 signaling pathways in vitroView study →}, C. ptosimopappa, C. omphalotricha), Saussurea (S. lappa ^{17Reference 17Cho JY et al. · 2000In vitroIn vitro anti-inflammatory effects of cynaropicrin, a sesquiterpene lactone, from Saussurea lappaView study →}, S. amara ^{26Reference 26Glasl S et al. · 2007AnimalCholeretic effects of the Mongolian medicinal plant Saussurea amara in the isolated perfused rat liverView study →}, S. salsa ^{34Reference 34Adekenov SM · 2026ReviewSesquiterpene γ-lactones of plants of the Asteraceae family of the flora of Kazakhstan: search, distribution, biological activity — reviewView study →}, S. pulchella, S. calcicola), Rhaponticum/Leuzea (R. carthamoides, whose leaves are a supercritical-CO2 extraction target for the compound ^{32Reference 32Sovová H et al. · 2008Supercritical fluid extraction of cynaropicrin and 20-hydroxyecdysone from Leuzea carthamoides DCView study →}), Centaurothamnus, Moquinia and Vernonia ^{10Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →}. A survey of 167 Asteraceae species of the Kazakh flora treats it as one of the genus-defining lactones of Saussurea and Rhaponticum ^{34Reference 34Adekenov SM · 2026ReviewSesquiterpene γ-lactones of plants of the Asteraceae family of the flora of Kazakhstan: search, distribution, biological activity — reviewView study →}.

Its role in the plant. Cynaropicrin is built from farnesyl diphosphate via (+)-germacrene A: germacrene A synthase (CcGAS) commits the carbon, germacrene A oxidase (CcGAO) and costunolide synthase (CcCOS) elaborate it, and leaf cynaropicrin content correlates with the expression of all three ^{3,27Reference 3Eljounaidi K et al. · 2015Accumulation of cynaropicrin in globe artichoke and localization of enzymes involved in its biosynthesisView study →Reference 27Menin B et al. · 2012Genetic mapping and characterization of the globe artichoke (+)-germacrene A synthase gene, encoding the first dedicated enzyme for biosynthesis of the bitter sesquiterpene lactone cynaropicrinView study →}. Functionally it is a chemical defence: it is a potent antifeedant against lepidopteran larvae and stored-product beetles ^{10Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →}, and it is phytotoxic — its soil degradation products (dehydrocynaropicrin and 4,15-dihydro-dehydrocynaropicrin) are more phytotoxic than the parent, which has made cardoon leaf waste a candidate bioherbicide feedstock ^{39Reference 39Rosa D et al. · 2026Stability studies of cynaropicrin — the major sesquiterpene lactone of Cynara cardunculus leavesView study →}. Trichome storage is the standard plant solution for keeping a self-toxic electrophile out of its own cytoplasm.

Discovery & Synthesis

First isolation and structure. Cynaropicrin was obtained from globe artichoke (Cynara scolymus) and its structure elucidated in 1960 by Suchý, Herout and Šorm at the Czechoslovak Academy of Sciences, as part of their long Terpenes series ^{1Reference 1Suchý M et al. · 1960On terpenesView study →}. The name is simply Cynara + picrin (from Greek pikros, bitter) — a naming convention that records what the molecule was recognised by. Its absolute stereochemistry was settled twelve years later by Corbella and colleagues, who related it chemically to alpha-santonin ^{2Reference 2Corbella A et al. · 1972Absolute stereochemistry of cynaropicrin and related guaianolidesView study →}.

Total synthesis. Despite being known for six decades, cynaropicrin resisted synthesis until 2021, when Nakamura and co-workers at Sophia University completed the first total synthesis, starting from (S)-alpha-pinene and hinging on a stereoselective Favorskii rearrangement and an indium-promoted diastereoselective Barbier reaction ^{33Reference 33Nakamura T et al. · 2021Total synthesis of cynaropicrinView study →}. Deuterated and derivative material had been made semi-synthetically from the natural product before then.

Manufacture today. Supply is entirely extraction from plant material, not synthesis — the 2021 route is a laboratory achievement, not a manufacturing one. Cynaropicrin is recovered from Cynara leaves (a waste stream of the artichoke industry, which discards ~80% of plant biomass as leaves and stems) and from Rhaponticum/Leuzea leaves. Reported recovery methods include gram-scale countercurrent chromatography ^{10Reference 10Elsebai MF et al. · 2016ReviewCynaropicrin: a comprehensive research review and therapeutic potential as an anti-hepatitis C virus agent — reviewView study →}, supercritical CO2 with ethanol modifier — used in Leuzea specifically to strip the bitter lactone out while retaining 89% of the 20-hydroxyecdysone ^{32Reference 32Sovová H et al. · 2008Supercritical fluid extraction of cynaropicrin and 20-hydroxyecdysone from Leuzea carthamoides DCView study →} — and green solvent systems (deep eutectic solvents, surface-active ionic liquids). In Kazakhstan, cynaropicrin extracted from Saussurea salsa is manufactured into the antiparasitic preparation “Sausalin” at the Karaganda Pharmaceutical Plant ^{34Reference 34Adekenov SM · 2026ReviewSesquiterpene γ-lactones of plants of the Asteraceae family of the flora of Kazakhstan: search, distribution, biological activity — reviewView study →}.

Patents: not yet researched.

Dosage

There is no established human dose for isolated cynaropicrin. It has never been trialled as a single agent in people, has no pharmacokinetic characterisation, and is only encountered as a constituent of artichoke and cardoon preparations. The figures below are research doses and content ranges, recorded so the in-vitro numbers can be put in context.

Note that the herbal preparations carrying cynaropicrin — standardised artichoke leaf extracts, typically 600-1,920 mg/day in trials — are dosed and standardised on caffeoylquinic acids, not on cynaropicrin, so cynaropicrin intake from them is incidental and variable ^{30Reference 30Pieri V · 2011Quantification of cynaropicrin in artichoke leaf extracts by 1H NMR spectroscopyView study →}. These are doses studied in research and are not a personal recommendation.