Essential Oil Composition of Two Tunisian Horehound Species: Marrubium vulgare L. and Marrubium aschersonii Magnus

Essential oils (EOs) obtained by hydrodistillation of the dried aerial parts of two horehound species: Marrubium vulgare L. and endemic Marrubium aschersonii Magnus (family Lamiaceae), were investigated by GC and GC-MS. Thirty five components and thirty seven components were identified respectively in EO of M. vulgare and that of M. aschersonii, They accounted for 74.6 % and 79.5 % of the whole oils. Both EOs were characterized by high amounts of sesquiterpenes (50.5 % and 37.7 %). β-bisabolene (28.3 %), β- caryophyllene (7.8 %), (E)-β-farnesene (7.4 %) and 1,8-cineole (4.8 %) were the major constituents of M. vulgare oil, while β-bisabolene (22.0 %), α-thujene (10.3 %), eugenol (10.1 %), α-humulene (6.2 %) were the major constituents of M. aschersonii oil.