Sesquiterpenes from Petasites hybridus rhizomes and determination absolute configuration by circular dichroism

Petasites hybridus, the butterbur is species belongs to the Asteraceae family is widely vegetated in Europe, Northwest Asia and North America [1]. It has been reported that this plant are treatment of headache, spasm of gastrointestinal, disturbances of the respiratory tract like bronchial asthma and many other illnesses [2]. Phytochemical investigation of n-hexane extract of the rhizome of P. hybriduse collected from north part of Iran has been carried out using normal phase column chromatography and RP-HPLC. Three known (1-3) together with two new (4-5) sesquiterpenoids have been isolated, purified and identified. The complete structures elucidated by application extensive 1D, 2D NMR and HRMS spectroscopy. Also the absolute configuration of 2 – 5 were achieved by comparison of experimental ECD spectra with simulated ECD data for possible stereoisomers, by using time dependent density function theory (TDDFT). The results shows that plants growing wild in Iran are new chemo type and these class of compounds are not reported from P. hybridus growing in Europe. Also P. hybridus known for presence pyrrolyzidine alkaloids. The amount of these compounds quantified by application of UPLC MRM ESIMS and showed high amount of senecionin-N-oxid and senecionin.

Fig. 1

[1] Khaleghi F, Din LB, Charati FR, Yaacob WA, Khalilzadeh MA, Skelton B, Makha M. Phytochemistry Letters 2011; 4: 254 – 258

[2] Lipton R, Göbel H, Einhäupl K, Wilks K, Mauskop A. Neurology 2004; 63: 2240 – 2244