Chemical composition of leaf and flower essential oils from Cyanthillium cinereum (L.) H. Rob., characterization of a new bergamotenal

The leaf and flower essential oils from Cyanthillium cinereum (Asteraceae), growing wild in C & ocirc;te d'Ivoire were investigated, using a combination of chromatographic [CC, GC(RI)] and spectroscopic [MS, 13C-NMR] techniques. A novel sesquiterpene identified as (E)-trans-beta-bergamotenal, was characterized. The oils from both plant parts were found to be rich in sesquiterpene hydrocarbons with concentration ranging from 78.4-87.6% in the flowers, and 72.1-91.8% in the leaves. In total, 43 constituents (91.5-96.7%) and 37 constituents (92.2-96.4%) were identified in the flower, and leaf oils, respectively. Major components of the flower oil were gamma-humulene (17.4-37.4%) and (E)-beta-caryophyllene (19.7-34.1%), followed by trans-beta-bergamotene (3.4-13.1%). The leaf oil composition was dominated by (E)-beta-caryophyllene (40.1-56.8%), with notable amounts of caryophyllene oxide (1.4-17.5%), germacrene D (1.8-11.4%), alpha-humulene (7.1-9.0%), guaia-6,10(14)-diene (3.6-8.9%) and gamma-humulene (0.3-5.9%). The hierarchical clustering analysis showed that flower and leaf essential oils from C & ocirc;te d'Ivoire are grouped in two distinct clusters and differed from samples collected in other countries.