Isolation and characterization of isomeric tibetin spiroethers from the roots of Tanacetum dolichophyllum (Kitam.) Kitam

Abstract

The roots of Tanacetum dolichophyllum (Kitam.) Kitam. (syn. Hippolytia dolichophylla (Kitam.) K.Bremer & Humphries) were collected from high altitude area of Munsyari, district Pithoragarh (Uttarakhand, India) yielded essential oil by steam distillation method and the oil was analysed by TLC and GC-MS. The GC-MS analysis of the essential oil sample showed the dominance of two constituents visible in sesquiterpene range. These constituents were isolated by column chromatography. The structures of these compounds were determined on the basis of 1H-NMR,13C NMR, COSY, 135-DEPT, and HRMS (ESI-TOF) spectral data. The two major compounds were identified as isomeric C14-Tibetin spiroethers, namely (E)-2-(2’,4’-heptadiyn-1’-ylidene)-1,6-dioxaspiro[4.4]non-3-ene and (Z)-2-(2’,4’-heptadiyn-1’-ylidene)-1,6-dioxaspiro[4.4]non-3-ene.