Constituents of the essential oil of Pulicaria gnaphalodes (Vent.) Boiss. from Iran

Abstract

The essential oil of Pulicaria gnaphalodes (Vent.) Boiss. from Iran was investigated by GC, CC-MS and NMR spectroscopy. Typical for this oil are pinane [chrysanthenone (23), cis-chrysanthenol (34)], cadinane [cadina-1(10),4-dien-8α-ol (114)] and bisabolane derivatives [nuciferol (118), γ-curcumen-12-ol (119)]. New, naturally occurring compounds are (Z)-3-methylnon-3-en-2-one (43), the so-called helifolen-12-als 94, 95, 98, 99, tricyclic sesquiterpene aldehydes with a helifolane (syn. allo-cedrane or khusiane) skeleton, and the italicen-12-ols 108 and 110. These aldehydes and alcohols are presumably formed by [4 + 2] resp. [2 + 2] cycloaddition of the corresponding γ-curcumene derivatives.