Chemical variability of essential oils in natural populations of Cupressus dupreziana

Abstract

Essential oils extracted from dried leaves of Cupressus dupreziana A. Camus, an endemic species in the Tassili n'Ajjer (Central Sahara of Algeria), were analyzed by gas chomatography coupled to mass spectrometry (GC-MS). Analyses were carried out on 164 trees of 26 natural populations in order to determine the intra-specific variability. Thirty-two terpenoïds were identified, the major ones being α-pinene (11.5-44.2), Δ3-carene (5.7-31.7) and germacrene-D (15.7-54.1). The terpenoid markers used made it possible to determine the individual patterns of chemotypic variability. This variability confirmed that genetic factors were not responsible for the decrease in the number of this species, the main reason probably being the Tassili n'Ajjer desertification.