Chemical Diversity of Essential Oils from Asteriscus graveolens (FORSSK.) LESS.: Identification of cis-8-Acetoxychrysanthenyl Acetate as a New Natural Component

Asteriscus graveolens is an endemic medicinal plant mainly distributed in south-western Algeria and south-eastern Morocco. The essential oils of leaves, stems, and flowers of A. graveolens had been studied by GC, GC/MS, and 13C-NMR. The spectral data of two nerolidol derivatives, 6-oxo- and 6-hydroxycyclonerolidol, were reassigned by 1D- and 2D-NMR spectroscopy. These compounds can be considered as chemical markers of this genus. The structure of a monoterpenic diester with a chrysanthenane skeleton, i.e., cis-8-acetoxychrysanthenyl acetate, was determined for the first time on the basis of GC/MS, and 1D- and 2D-NMR. The stem and leaf oils were characterized by high content of oxygenated sesquiterpenes with 6-oxo- and 6-hydroxycyclonerolidol as major components, and the flower essential oils were dominated by the new monoterpenic compound cis-8-acetoxychrysanthenyl acetate.