“…Diterpenoids analysis have revealed that the species occurring in the Eastern and Central Mediterranean area (Turkey, Greece and Italy) contain almost exclusively kaurane diterpenes (Topç u et al, 1999(Topç u et al, , 2002aFraga et al, 2003a,b;Kilic et al, 2003;Kilic, 2006), whereas species growing in Western Mediterranean area and Macaronesic regions present diterpenes with different carbon skeleta (ent-kaurene, labdane, atisene, pimarane, beyerane, trachilobane and rosane) (de Quesada et al, 1974;Márquez et al, 1975;García-Granados et al, 1982;Cabrera et al, 1983). Kaurene diterpenes derivatives (foliol (5), sidol, linearol, sideridiol and isolinearol) are the most frequently found in Sideritis species.…”