Two new eudesman-4α-ol epoxides from the stem essential oil of <i>Laggera pterodonta</i> from Côte d’Ivoire

Abstract

The investigation of the stem essential oil of <i>Laggera pterodonta</i> (DC.) Sch. Bip. ex Oliv. (Asteraceae) from Côte d'Ivoire was carried out, using a combination of chromatographic (GC-RI, CC, pc-GC) and spectroscopic (GC-MS, ¹³C NMR) techniques. This study led to the identification of fifty constituents of which two new natural compounds 7β,11β-epoxy-eudesman-4α-ol and 7α,11α-epoxy-eudesman-4α-ol. Their structures were elucidated by 1 D and 2 D NMR spectroscopy after pc-GC purifying. Finally, 98.9% of the whole composition of the oil was identified with a high amount of 2,5-dimethoxy-<i>p</i>-cymene (78.9%). The other significant components were α-humulene (6.2%), (<i>E</i>)-β-caryophyllene (1.7%), thymyl methyl oxide (1.7%), α-phellandrene (1.5%), <i>p</i>-cymene (1.2%), (3αH,4βH,6αH,1αMe)-1,6-epoxy-3-hydroxycarvotanacetone angelic acid ester (1.1%) and 10-<i>epi</i>-γ-eudesmol (1.0%).