Leaf essential oil composition of Inula cuspidata (Wall. ex DC.) CB Clarke from India

The hydrodistilled leaf essential oil of Inula cuspidata (Wall. ex DC) C. B. Clarke was investigated using capillary gas chromatography-flame ionization detector (GC-FID) and GC-mass spectrometry (GC-MS). A total of fifty-two constituents, representing 83.4% of the total oil composition were identified. The oil was mainly dominated by sesquiterpenoids (78.1%) with small amounts of monoterpenoids (3.0%) and benzenoid components (2.7%). The major constituents of the essential oil were presilphiperfolan-8-ol (17.4%), ar-curcumene (17.0%), (E)-beta-farnesene (8.2%), isoledene (6.7%), presilphiperfol-7-ene (5.5%), (E)-caryophyllene (4.1%), silphiperfol-6-ene (3.8%), silphinene (3.0%), cameroonal-7-alpha-ol (2.6%), alpha-pinene (1.8%) and silphiperfol-5-ene (1.5%). Characteristic of the I. cuspidata leaf oil was the presence of rare tricyclic sesquiterpenoids in larger amounts. To the best of our knowledge, at least forty-five constituents were identified for the first time in I. cuspidata leaf essential oil.