Petasites hybridus (L.) G.Gaertn. - syn.Petasites officinalis Moench; Tussilago hybrida L. - Asteraceae
(common) butterbur, bog-rhubarb, (Gewöhnliche) Pestwurz
Dioecious perennial herb, up to 60cm high, native to Europe and Western Asia; flowers white to pink-purple, all without rays, produced in the early spring before the leaves; basal leaves huge, long-petioled, ovate-cordate, serrulate, tomentose beneath, up to 60cm in diameter, reniform to orbicular.
„The plants are functionally dioecious, the staminate flowers without rays but marginal pistillate ones often with conspicuous though relatively short rays. Pistillate heads may have numerous rays.“
http://michiganflora.net/genus.aspx?id=Petasites
„Three spasmolytically active substances which contain no nitrogen, namely petasin and the petasolesters B and C, were isolated from Petasites officinalis Moench. They are all esters of the same C15-alcohol. Petasin is an ester of angelic acid, whereas the petasolesters B and C are derivates of a new acid containing sulphur, the β-methylmercapto-acrylic acid.“
[Über Inhaltsstoffe ausPetasites officinalis Moench I. Petasin und die Petasolester B und C., Stoll, A., Morf, R., Rheiner, A., Renz, J., Experientia, Vol.12(9), 1956, 360-362]
„Seperation of a mixture of sesquiterpene hydrocarbons from coltsfoot rhizomes (Petasites officinalis Moench) afforded following compounds: β-elemene, α- and β-humulene, β- and γ-bisabolene, two new sesquiterpenic hydrocarbons petasitene and eremophilene, and a derivative of eremophilane type, furanoeremophilane.“
[On terpenes. CXXXVIII. Sesquiterpenic hydrocarbons from coltsfoot rhizomes (Petasites officinalis MOENCH.)., Hochmannova, J., Novotný, L., Herout, V., Collection of Czechoslovak Chemical Communications, Vol.27(8), 1962, 1870-1876]
By HPLC, 14 genuine sesquiterpenes of P.hybridus were seperated from different plant parts (rhizome, roots, runners, buds, leaves and stalks). „The six main compounds (isopetasin 1b, neopetasin 2b, petasin 3b, iso-S-petasin 1f, neo-S-petasin 2f and S-petasin 3f) have been quantitatively determined. These compounds are abundant in a subterranean parts, with the exception of isopetasin 1b, which is found in somewhat higher concentrations in leaves than in roots. In all the subterranean parts petasin 3b, which is known to have the highest spasmolytic activity, is by far the most important sesquiterpene ester. In a typical specimen, highest contents of petasin have been found in the rhizomes (9376 μg/g dried material), followed by the runners and the roots with 7018 and 7002 μg/g, respectively.“
[Sesquiterpenes of Petasites hybridus (L.) GM et Sch.: distribution of sesquiterpenes over plant organs., Debrunner, B., Neuenschwander, M., Brenneisen, R., Pharmaceutica Acta Helvetiae, Vol.70(2), 1995, 167-173]
Six furanoeremophilanes have been isolated from fresh extracts of subterranean parts of P.hybridus. „Total sesquiterpene contents only slightly vary within the same population but moderately vary in four different habitats (Schwarzwald area, southern Germany). On the other hand, in total extracts relative amounts of main compounds 9-hydroxy-furanoeremophilane (2, 31–35%), furanopetasin (3, 18–22%) and 2-methylthioacryloyl-furanopetasol (6, 7–11%) are surprisingly constant for these four habitats, based on the same amount of extract. Contrary to the extracts of rhizomes, extracts of flowers contain 9-oxo-furanoeremophilane (2a) and 9-oxo-furanopetasin (3a) as main components instead of 2 and 3. Compounds 3 and 3a are the main constituents of extracts of leaves, but the composition of these extracts is much more complex.“
[Sesquiterpenes from Petasites hybridus (Furanopetasin chemovar): separation, isolation and quantitation of compounds from fresh plant extracts., Siegenthaler, P., Neuenschwander, M., Pharmaceutica Acta Helvetiae, Vol.72(2), 1997, 57-67]
„Various locations in Switzerland were screened for Petasites hybridus plants with high petasin and low pyrrolizidine alkaloid content. The mean petasin content of the various populations ranged from 7.4 to 15.3 mg/g dry weight in rhizomes and from 3.3 to 11.4 mg/g dry weight in leaves. Mean pyrrolizidine alkaloid content in rhizomes ranged from 5 to 90 ppm whereas leaves contained between 0.02 to 1.50 ppm. These results suggest that leaves might be a preferable source for harvesting compared to the underground organ due to the finding of high petasin contents and consistently lower amounts of toxic pyrrolizidine alkaloids.“
[Quantitative analysis of petasin and pyrrolizidine alkaloids in leaves and rhizomes of in situ grown Petasites hybridus plants., Wildi, E., Langer, T., Schaffner, W., Büter, K.B., Planta medica, Vol.64(3), 1998, 264-267]
„Here, we investigated the effects of a plant extract of petasites hybridus (Ze339) and its isolated active sesquiterpene ester petasin in these two in vitro cell models. Zileuton, a 5-lipoxygenase inhibitor, was used as a positive control. All compounds inhibited both cysteinyl-LT synthesis in eosinophils and LTB4 synthesis in neutrophils. In contrast, only Ze339 and petasin, but not zileuton, abrogated PAF- and C5a-induced increases in intracellular calcium concentrations. These data suggest that Ze339 and petasin may block, compared to zileuton, earlier signalling events initiated by G protein-coupled receptors in granulocytes, perhaps at the level of or proximal to phospholipase Cβ. Taken together, petasin appears to be one major active compound of petasites hybridus extract, since it demonstrates the same inhibitory activities on calcium fluxes and subsequent LT generation in both eosinophils and neutrophils as Ze339 does.“
[Role of petasin in the potential anti-inflammatory activity of a plant extract of Petasites hybridus., Thomet, O.A., Wiesmann, U.N., Schapowal, A., Bizer, C., Simon, H.U., Biochemical pharmacology, Vol.61(8), 2001, 1041-1047]
„The sesquiterpenes inhibit the formation of leucotrienes and exhibit spasmolytic and analgesic properties. Controlled clinical studies show a positive effect in the tretment of patients with chronic headache and migraine.“
[Medicinal Plants of the World. Ben-Erik Van Wyk and Michael Wink, Pretoria 2004, 234]
There are two varieties with different chemical compositions, which can not be accurately differentiated. This chemical varieties may also be distinguished by steam distillation. Typical constituents of the rhizomes of the furan variety are furanopetasin and 9-hydroxy-furanoeremophilane.
[Hagers Handbuch der Pharmazeutischen Praxis, Springer 2010]
„Allergic rhinitis symptoms of itching, sneezing, rhinorrhea, and nasal obstruction significantly decrease patients’ quality of life. Compared with histamine and leukotriene receptor antagonists, the petasol butenoate complex Ze 339 displays pharmacologically distinct properties. In vitro it inhibits the biosynthesis of leukotrienes and mediator release from activated eosinophils.“
[Petasol butenoate complex (Ze 339) relieves allergic rhinitis–induced nasal obstruction more effectively than desloratadine., Dumitru, A.F., Shamji, M., Wagenmann, M., Hindersin, S., Scheckenbach, K., Greve, J., Chaker, A.M., Journal of Allergy and Clinical Immunology, Vol.127(6), 2011,1515-1521]
Blackwell, E., Herbarium Blackwellianum, vol.3, t.222 (1757)
http://plantgenera.org/species.php?id_species=771911
Petasites hybridus CC BY-SA 3.0, Author: Andreas Kraska