Volatile compounds of flowers and leaves of Sideritis italica (Miller) Greuter et Burdet (Lamiaceae), a plant used as mountain tea

Sideritis italica (Miller) Greuter et Burdet (Lamiaceae), widely used in ethnopharmacological medicine, occurs in Southern Italy and Sicily. The phytochemical composition of the essential oils of S. italica flowers and leaves, harvested in Piano Battaglia (Sicily), was analysed by GC and GC-MS. Of the 51 compounds, 43 in the oil from flowers and 29 in the oil from leaves were identified. Kaur-15-ene (20.0%) was recognised as the main constituent of the oil from flowers, together with -cubebene (12.1%), -pinene (8.5%), (Z)-nuciferol (6.5%), tricyclene (4.5%) and -bisabolol (4.0%). In the oil from leaves, p-methoxyacetophenone (26.0%) prevailed, as did hexadecanoic acid (21.3%), followed by nonanal (4.8%), -bisabolol (4.5%) and -cubebene (4.7%).