Composition of the essential oil of Juniperus cedrus Webb & Berth. grown on Madeira

The essential oils isolated from twigs of Juniperus cedrus Webb & Berth. grown on Madeira were analysed by GC, GC–MS and 13C‐NMR. The oils consisted mainly of monoterpene hydrocarbons (53.1–87.8%), the main ones being α‐pinene (19.6–55.3%), limonene (17.3–32.7%) and Δ‐3‐carene (5.5–15.7%). The sesquiterpenoid fraction (4.1–22.3%) was dominated by E‐caryophyllene (1.6–7.4%), while sandaracopimaradiene (0.1–6.1%), isoabienol (0.5–1.3%) and trans‐totarol (0.4–2.2%) were the main diterpenoids (2.2–11.9%). Oct‐1‐en‐3‐ol (1.0–2.2%) was the major constituent of the non‐terpenic fraction (1.3–2.7%). The composition of our oil samples differed to some extent from that reported for J. cedrus oil grown on the Canary Islands.