Sesquiterpene Lactones in Arnica montana: Helenalin and Dihydrohelenalin Chemotypes in Spain

Abstract

An analytical RPLC method for sesquiterpene lactones in Arnica montana has been extended to include quantitative analyses of dihydrohelenalin esters. LC‐ESI‐MS‐MS distinguished the isomeric helenalin and dihydrohelenalin esters. The dihydrohelenalin esters have lower response factors for UV detection than do helenalin esters, which must be taken into account for quantitative analyses. Analyses of flowers from 16 different wild populations of A. montana in Spain showed differing proportions of helenalin and dihydrohelenalin esters. For the first time a chemotype with high levels of helenalin esters (total helenalins 5.2–10.3 mg/g dry weight) is reported in Spanish A. montana. These samples were from heath lands at high altitude (1 330–1 460 m), whereas samples from meadows and peat bogs at lower altitudes were the expected chemotype with high levels of dihydrohelenalin esters (total dihydrohelenalins 10.9–18.2 mg/g). The phenolic compounds, both flavonoid glycosides and caffeoylquinic acids, in Spanish A. montana are reported for the first time. The levels of several of these compounds differed significantly between samples from heath lands and samples from peat bogs or meadows, with the heath land samples being most similar to central European A. montana in their phenolic composition.

Key words

sesquiterpene lactones - phenolics - Arnica montana - Asteraceae - LC‐MS - chemotypes

References

• 1 Ferguson I K. Arnica L. Tutin TG, editor. Flora europaea. Cambridge; University Press 1976: 189-190
• 2 Bolos y Vayreda A. El Arnica montana L. en la Península Ibérica. Farmacognosia.  Anales del Instituto José Celestino Mutis. 1947;  7 145-151
• 3 Willuhn G. Arnicae flos. Wichtl M, editor. Herbal drugs and phytopharmaceuticals. Medpharm Stuttgart; Scientific Publishers 2004: 54-59
• 4 Siedle B, Garcia-Pineres A J, Murillo R, Schulte-Monting J, Castro V, Rungeler P, Klaas C A, Da Costa F B, Kisiel W, Merfort I. Quantitative structure-activity relationship of sesquiterpene lactones as inhibitors of the transcription factor NF-kappa B.  J Med Chem. 2004;  47 6042-6054
• 5 Anonymous. Arnica flower (1391). Strasbourg: European Pharmacopoeia 5.0 2005: 1022-1023
• 6 Willuhn G, Leven W, Luley C. Arnikabluten DAB 10. Untersuchungen zur qualitativen und quantitativen Variabilität des Sesquiterpenlactonegehaltes der offizinellen Arnikadrogen.  Dtsch Apoth Ztg. 1994;  134 4077-4085
• 7 Klaas C A, Wagner G, Laufer S, Sosa S, Loggia R D, Bomme U, Pahl H L, Merfort I. Studies on the anti-inflammatory activity of phytopharmaceuticals prepared from Arnica flowers.  Planta Med. 2002;  68 385-391
• 8 Hausen B M. Identification of the allergens of Arnica montana L.  Contact Dermatitis. 1978;  4 308
• 9 Hausen B M, Herrmann H D, Willuhn G. The sensitizing capacity of Compositae plants. I. Occupational contact dermatitis from Arnica longifolia Eaton.  Contact Dermatitis. 1978;  4 3-10
• 10 Herrmann H D, Willuhn G, Hausen B M. Helenalinmethacrylate, a new pseudoguaianolide from the flowers of Arnica montana L. and the sensitizing capacity of their sesquiterpene lactones.  Planta Med. 1978;  34 299-304
• 11 Hausen B M, Schmalle H W. Structure-activity aspects of 4 allergenic sesquiterpene lactones lacking the exocyclic alpha-methylene at the lactone ring.  Contact Dermatitis. 1985;  13 329-332
• 12 Douglas J A, Smallfield B M, Burgess E J, Perry N B, Anderson R E, Douglas M H, Glennie V L. Sesquiterpene lactones in Arnica montana: a rapid analytical method and the effects of flower maturity and simulated mechanical harvesting on quality and yield.  Planta Med. 2004;  70 166-170
• 13 Woerdenbag H J, Merfort I, Schmidt T J, Passreiter C M, Willuhn G, Uden W V, Pras N, Konings A WT. Decreased helenalin-induced cytotoxicity by flavonoids from Arnica as studied in a human lung carcinoma cell line.  Phytomedicine. 1995;  2 127-132
• 14 Spitaler R, Schlorhaufer P D, Ellmerer E P, Merfort I, Bortenschlager S, Stuppner H, Zidorn C. Altitudinal variation of secondary metabolite profiles in flowering heads of Arnica montana cv ARBO.  Phytochemistry. 2006;  67 409-417
• 15 Poplawski J, Holub M, Samek Z, Herout V. Arnicolides – sesquiterpenic lactones from leaves of Arnica montana L. Coll.  Czechoslov Chem Commun. 1971;  36 2189-2199
• 16 Willuhn G, Rottger P M, Matthiesen U. Helenalin- and 11, 13-dihydrohelenalin esters from the flowers of Arnica montana.  Planta Med. 1983;  49 226-231
• 17 Schmidt T J. Helenanolide type sesquiterpene lactones. Part 1. Conformations and molecular dynamics of helenalin, its esters and 11, 13-dihydro derivatives.  J Mol Struct. 1996;  385 99-112
• 18 Perry N B, Burgess E J, Lorimer S D, van Klink J W. Fatty acid anilides as internal standards for high performance liquid chromatographic analyses of Valeriana officinalis L. and other medicinal plants.  Phytochem Anal. 1996;  7 263-268
• 19 Anonymous<. Arnica tincture (1809). Strasbourg: European Pharmacopoeia 5.1 2005: 2877-2878
• 20 Seeber H. Kulivierung und Analytik der Arnica montana L. Arnika als Sonderkultur in Südtirol [Diploma thesis]. Innsbruck; Leopold-Franzens-Universitat 1996
• 21 Willuhn G, Leven W. Zur qualitativen und quantitativen Analyse der Sesquiterpenlactone von Arnikablüten DAB 9.  Pharm Ztg Wiss. 1991;  139 32-34
• 22 Merfort I. Caffeoylquinic acids from flowers of Arnica montana and Arnica chamissonis.  Phytochemistry. 1992;  31 2111-2113
• 23 Lass C, Vocanson M, Wagner S, Schempp C M, Nicolas J F, Merfort I, Martin S F. Anti-inflammatory and immune-regulatory mechanisms prevent contact hypersensitivity to Arnica montana L.  Exp Dermatol. 2008;  17 849-857
• 24 Wagner S, Merfort I. Skin penetration behaviour of sesquiterpene lactones from different Arnica preparations using a validated GC‐MSD method.  J Pharm Biomed Anal. 2007;  43 32-38
• 25 Schmidt T J, Bomme U, Alfermann A W. Sesquiterpene lactone content in leaves of in vitro and field cultivated Arnica montana.  Planta Med. 1998;  64 268-270