Practical ecological knowledge for the temperate reader.



  • Ranunculaceae spp [EncyTCMV.1][HPIP Shih]
    • Actaea alba; Actaea arguta; Actaea pachypoda; [PTH]
    • Actaea rubra [PTH][Polya BTPBC]
    • Anemone Spp. [Polya BTPBC]
    • Anemone cernua [CRNAH]
    • Anemone hepatica [CRNAH]
    • Anemone nemorosa - Wood anemone[PDR] 0.33 mg/g (wet weight) [Barceloux MTNS]
    • Anemone patens [CRNAH]
    • Anemone pulsatilla [CRNAH]
    • Anemone trifolia 0.17 mg/g (wet weight) [Barceloux MTNS]
    • Caltha palustris, [EncyTCMV.1][Jernigan EYK][CRNAH][LLCEOPS]
    • Clematis Spp. [Polya BTPBC]
    • Clematis chinensis, [EncyTCMV.1]
    • Clematis flammula 0.50 mg/g (wet weight) [Barceloux MTNS]
    • Clematis recta [PDR] 0.01 mg/g (wet weight) [Barceloux MTNS]
    • Clematis vitalba [Pieroni 1999] 0.15 mg/g (wet weight) [Barceloux MTNS]
    • Helleborus foetidus 0.67 mg/g (wet weight) [Barceloux MTNS]
    • Helleborus niger [Adams et al., 2009] 5.82 mg/g (wet weight) [Barceloux MTNS]
    • Hepatica nobilis - American Liverleaf [PDR]
    • Helleborus odorus 0.004 mg/g (wet weight) [Barceloux MTNS]
    • Pulsatilla chinensis, [EncyTCMV.1][CRNAH]
    • Pulsatilla pratensis - Pasque Flower [PDR]
    • Pulsatilla vulgaris [HerbalMed3][CRNAH]
    • Ranunculus Spp. [Polya BTPBC]
    • Ranunculus acris - Buttercup [PDR]
    • Ranunculus bulbosus 7.77 mg/g (wet weight) [Barceloux MTNS] High levels (of Ranunculin) [Cheryll Williams][LLCEOPS]
    • Ranunculus cantoniensis, [EncyTCMV.1]
    • Ranunculus chinensis [CRNAH]
    • Ranunculus flammula High levels (of Ranunculin) [Cheryll Williams]
    • Ranunculus ficaria - Pilewort [HerbalMed3]
    • Ranunculus gramineus High levels (of Ranunculin) [Cheryll Williams]
    • Ranunculus hirsutus [LLCEOPS]
    • Ranunculus japonicus, [EncyTCMV.1][CRNAH]
    • Ranunculus repens 0.13 mg/g (wet weight) [Barceloux MTNS] 0.27% (of Ranunculin) [Cheryll Williams]
    • Ranunculus sardous High levels (of Ranunculin) [Cheryll Williams]
    • Ranunculus sceleratus, [EncyTCMV.1][Misra&Dixit][PDR][CRNAH][LLCEOPS]
    • Ranunculus stevenii High levels (of Ranunculin) [Cheryll Williams]

"The family Ranunculaceae (buttercup) has various species in a number of genera that contain the skin irritant, protoanemonin, including species of the genera Anemone, Caltha (marsh marigold), Clematis (clematis, leather flower), Pulsatilla, Helleborus (hellebore), and Ranunculus (buttercup)." [Barceloux MTNS] "Protoanemonin (85) yielding compounds are known to occur in the genera Anemone, Ceratophalus, Clematis, Clematopsis, Helleborus, Hepatica, Knowltonia, Myosurus, Pulsatilla, Ranunculus, and Trautvetteria (Hegnauer, 1973; Ruijgrok, 1966). The results of numerous tests indicate that these glycosides do not occur in Aconitum, Actaea, Adonis, Anemonella, Anemonopsis, Aquilegia, Callianthemum, Caltha, Cimifuga, Consolida, Coptis, Delphinium, Erantis, Hydrastis, lsopyrum, Leptopyrum, Nigella, Semiaquilegia, Thalictrum, Trollius, and Zanthorhiza (Hegnauer, 1973)." [Seiger PSM] "Most members of the buttercup family contain an irritating compound, protoanemonin, in their fresh leaves, stems, roots, flowers and seeds (cf. Turner, 1984). Hence, all must be cooked before eating." [Turner, Kuhnlein][Vizgirdas WPSN]

"The vesicant (blistering) reputation of the genus is linked to a pale yellow oil that contains protoanemonin..." [Cheryll Williams] "Turner and Szczawinski (1991) explain that the acrid compound is protoanemonin, an enzymatic breakdown product of the glycoside ranunculin. When the plants are dried, the protoanemonin becomes the innocuous anemonin." [Daniel F. Austin]

"There are a variety of herbal uses in traditional medicine for protoanemonin - containing species including Anemone and Pulsatilla species. The most common use by Native American peoples for these plants was as a counter - irritant in the form of an external poultice for abrasions, boils, cuts, and skin sores.1 Other traditional uses for extracts from these plants included rheumatism, stomach troubles, and promoting childbirth." [Barceloux MTNS]


"Death by asphyxiation following the intake of large quantities of protoanemonine-forming plants has been observed in animal experiments." [PDR]

"Poisoning from protoanemonin in animals and humans has similar symptoms: stomach pain, throat inflammation, salivation, cracked and excoriated tongue, smarting teeth, tenderness, and bleeding of the cornea of the eye (Millspaugh 1892)." [Cheryll Williams] Few Human reports. "Bloody emesis and diarrhea develop in association with severe abdominal cramps. Central nervous system involvement is manifested by dizziness, syncope, and seizures....Most exposures result in minimal or no toxicity."[HPIP Shih] "Protoanemonin is known to be a central nervous system depressant and to induce abortions." [Skidmore-Roth MHH]

Clematis recta: "Extended skin contact with the freshly harvested, bruised plant can lead to blister formation and cauterizations that heal poorly, due to the released protoanemonine, which is severely irritating to the skin and mucous membranes. If taken internally, severe irritation to the gastrointestinal tract, combined with colic and diarrhea, as well as irritation of the urinary drainage passages, are possible." [PDR]


"Vesicant; antibiotic; antibacterial (Bacillus coli, MIC = 12~30 mol/L; Staphylococcus aureus, MIC = 16.7 mol/L; Shigella shigae, MIC = 16.7 mol/L; Mycobacterium tuberculosis, MIC = 2.5 mol/L)." [EncyTCMV.1] "Protoanemonin, albeit a powerful vesicant agent, has effective antibacterial, antifungal, antimutagenic and anthelmintic activity. Protoanemonin, however, is highly unstable and is readily converted to a more inert derivative, anemonin – which is much less active, although it retains antibacterial properties." [Cheryll Williams] "...the monomer protoanemonin gradually dimerised into its dimer anemonin. Therefore, the compound must be stored in a deep freeze. ... It was noted that the freshly prepared active principle protoanemonin and its dimer anemonin completely inhibited the mycelial growth of all the test fungi up to 1:10,000 and 1:100 dilutions, respectively" [Misra&Dixit] "Protoanemonin with significant antiseptic activity on aerobes, anaerobes, dermatophytes, and yeast, including MDR pathogens." "antibacterial (against Gram-positive and Gram-negative, Candida, diphtheria toxin, Escherichia, and Staphylococcus) antiviral, cytopathogenic, vesicant, vermicide (WOI)."[HMH Duke] "Both anemonin and protoanemonin have antifungal properties (Misra and Dixit, 1980)."[Seiger PSM]

"Protoanemonin is stated to have a marked ability to combine with sulfhydryl (-SH) groups and it is thought that the toxic subdermal properties of protoanemonin may depend on the inactivation of enzymes containing -SH groups.(G33) An LD50 value (mice, intraperitoneal injection) for anemonin has been reported as 150 mg/kg body weight." [HerbalMed3]

"The glycoside ranunculin: changes enzymatically when the plant is cut into small pieces, and probably also when it is dried, into the pungent, volatile protoanemonine that quickly dimerizes to non-mucous-membrane irritating anemonine. When dried, the plant is not capable of protoanemonine formation." [PDR] "The biting taste and blistering properties of many species of the Ranunculaceae are well known. These properties are caused by protoanemonin (85), which is formed by a complex set of reactions. The precursor ranunculoside (86) is converted to ranunculin (87), hence to protoanemonin, and subsequently by dimerization to anemonin (88) (Hegnauer, 1984; Nahrstedt, 1979). Protoanemonin, which arises by cleavage of ranunculin by glucosidases found in the plant, also has been isolated by steam distillation of plant material. Protoanemonin spontaneously dimerizes to form anemonin (Hegnauer, 1973)." [Seiger PSM]

"From past work two lactones, anemonin and protoanemonin were obtained and considered as its antiinflammatory compounds. But recent pharmacological studies showed that such effects were very weak. " [Yang APG]

"...protoanemonin, a constituent of ... [Ranunculus] damascenus, which inhibits mitosis in plants" [SEHM]


Evidence From Plants

"Drying or boiling of protoanemonin - containing herbs destroys the irritant properties in Anemone and Pulsatilla species by accelerating the polymerization of protoanemonin.... Protoanemonin occurs in varying concentrations in different species with the highest concentrations (0.5 – 0.8%) in bulbs from Ranunculus bulbosus L. and Helleborus niger L. " [Barceloux MTNS]

Caltha palustris: "The leaves and stem are collected early, before they flower in the summer. They are boiled, changing the water two or three times to leach out toxic chemicals, including protoanemonin before eating." [Jernigan EYK] " In its raw state, marsh marigold is a toxic plant, due to the presence of protoanemonin. In this area it is dried or lactofermented before use." "Protoanemonin is broken down by drying and long cooking [43,44]. In the study area, the plant is either dried and then used like other wild greens, or it is lacto-fermented after the initial blanching. The dried specimens of marsh marigolds we ate had no bitterness even prior to cooking. Further studies are needed to establish if the local population of marsh marigolds is a low-protoanemonin form easier to prepare as food than the European Caltha. For example, one of the authors’ (ŁŁ) unpublished experiments show that C. palustris from Poland needs one to two hours of cooking to get rid of the bitterness caused by protoanemonin." [Kang et al., 2014]

"Clematis contains acrid, toxic compounds.... Rafinesque (1830) noted: “Bark and blossoms acrid, raising blisters on the skin; a corrosive poison internally, loses the virulence by cooking.” The French (herbe aux gueux) and Spanish (hierba de los pordioseros) names referring to beggars are a reference to their past use to irritate the skin to simulate sores and induce sympathy from potential donors (Bown 1995). Ingestion of any part of extracts may cause vomiting of blood, severe diarrhea, and convulsions (Foster and Duke 1990)." [Daniel F. Austin]

Pulsatilla Sp, "Pulsatilla is considered specific for painful or inflammatory reproductive conditions, including dysmenorrhea... Its sedative action is beneficial when there is nervous tension causing or accompanying dysmenorrhea, and it also exerts pronounced effects on uterine pain.... No pharmacologic or clinical trials were identified on this herb. Only the dried herb is used. Fresh plant contains an irritating component, protoanemonin.... This plant is teratogenic and abortifacient in cattle, and should not be used during pregnancy." [BMWH]

Pulsatilla pratensis - Pasque Flower; Whole plant used fresh to prevent migrane. 0.2-0.6g daily dose. Aerial Parts used as a herbal antiseptic in the "...treatment of infections of the skin and skin structures" [Capasso PQR] Synonym of Anemone pratensis (2/3 confidence) [ThePlantList]

Pulsatilla vulgaris: " Fresh pulsatilla is poisonous because of the toxic volatile oil component, protoanemonin. Protoanemonin rapidly degrades to the non-toxic anemonin. Inhalation of vapour from the volatile oil may cause irritation of the nasal mucosa and conjunctiva.... External contact with the fresh plant should be avoided. The toxic principle, protoanemonin, rapidly degrades to the non-toxic anemonin during drying of the plant material. " [HerbalMed3]

Ranunculus Sp.; "It [protoanemonin] may be removed from the plants by thorough cooking. If any acid taste remains, spit out the mouthful, and recook the plants in fresh water." [Kirk WEP]

Ranunculus bulbosa; "Studies of Ranunculus bulbosus have reported signifcant antimicrobial properties for protoanemonin (a lactone), particularly against various Streptococcus bacteria. It is of particular interest that the antimicrobial effect could be enhanced by combination with various conventional antibiotic drugs. Tis activity was linked to the ability of protoanemonin to penetrate the microbes’ cell walls, thereby facilitating the entry of the antibiotic, with a resultant enhancement of its efficacy (Didry 1993)." [Cheryll Williams] "R. bulbosus (also an Old World native) is one of the best in providing edible roots. Early western settlers pickled the young flowers.... It has been reported by some authors that the bulbs of R. bulbosus which have wintered over are mild enough to eat raw in the spring, but this is probably risky." [Kirk WEP]

Related Compounds


Page last modified on Saturday, January 1, 2022 10:25 AM