abstract the chemical composition of the essential oils obtained from the flowering aerial parts of marrubium vulgare l.. and marrubium peregrinum l. were determined by gc/ms. twelve components were identified in m. vulgare oil with -caryophyllene (45.8%) and germacrene d (14.4%) being the major constituents. in m. peregrinum oil, sixteen compounds were identified with -caryophyllene (31.3%), germacrene d (28.1%) and bicyclogermacrene (15.3%) predominating.