COMPOSITION OF THE ESSENTIAL OIL OF MELANOSELINUM-DECIPIENS (SCHRAD. AND WENDL.) HOFFM., AN ENDEMIC SPECIES OF THE MADEIRA AND AZORES ARCHIPELAGOS

The composition of the essential oils from the aerial parts of Melanos elinum decipiens (Schrad, & Wendl.) Hoffm., collected during the veget ative phase on Madeira and on the Azores, respectively, was analysed b y GC and GC-MS. Both oils consisted mainly of monoterpenes (87% and 86 % for Madeiran and Azorean oils, respectively), beta-pinene (72%) and limonene (82%) being the main components of the Madeiran and Azorean o ils, respectively. The sesquiterpene fraction attained 7% of the oil i solated from the Madeiran plants, whereas 5% was found in the oil isol ated from the Azorean M. decipiens, the latter consisting only of hydr ocarbons. This oil contained a higher non-terpenoid fraction, dominate d by n-nonane (4%), than that of the Madeiran M. decipiens (7% and 1%, respectively). (C) 1997 John Wiley & Sons, Ltd.