Chemical composition of essential oils in the leaves of Delairea odorata during flowering and post-flowering periods

摘要: on their mass spectra. The percentage of essential oil isolated was 1.6%, and the major compounds identified were germacrene D (17.9%), caryophyllene (11.9), trans-isocroweacin (9.6), acoradiene (7.6), -curcumene (6.5%) during flowering season. During post -flowering period trans--bergamotene (36.8%), trans--ocimene (16.5), bicyclo[7.2.0]undec-4-ene (11.5) carene (9.3) identified, extract 1.9%. chemical composition D. odorata completely different from Senecio scandens [4]. Though there is confusion in differentiating S. with this variation volatile composition, we suggest that a species. differences yield can partly be attributed to types secretory structures [5]. Both post-flowering periods, oils dominated by sesquiterpenes, which constitute about 89.1 42.1%, respectively. There considerable amount alkenes (11.9%) alkanes (6.6%) recorded period. terpene turnover depends photosynthesis utilization photosynthates [6]. Bergamotene compound vegetative phase plays an important role as insect repellent [7]. higher concentration bergamotenes may reason why has no natural insects feeding them study area. decrease evolutionary strategy adapted plant attract pollinating agents. These variations obtained constitution due fact fruiting events influenced biotic abiotic factors.