Chemical components of essential oils of four Eucalyptus L'Her. species cultivated in Kashan’s botanical garden, Iran

Abstract

Background & Aim: <em>Eucalyptus</em> L'Her. [an aromatic genera of the family (Myrtaceae)] is native to Australia and other tropical species is planted worldwide. The purpose of this study is to extract and identify the essential oils components of four species of <em>Eucalyptus</em> L'Her. cultivated in botanical garden of Kashan, Central Iran. Experimental: Leaves of <em>E. largiflorens</em>, <em>E. intertexta</em>, <em>E. torquata</em> and <em>E. loxophleba</em>, were collected from the botanical garden in Kashan. Extracting was done by hydro-distillation method and Clevenger approach. Components of essential oils were identified using GC and GC/MS analysis. Results & Discussion: The essential oil yield of <em>E. largiflorens</em> was 1.85% (v/w) and, nineteen compounds were identified. The major components in the essential oil were 1,8-cineol (58.71%), <em>p</em>-cymene (12.42%), <em>α</em>–pinene (5.61%) and terpinen-4-ol (4.53%). Yield of the essential oil of <em>E. intertexta</em> was 1.5% (v/w) and, sixteen components were identified which the major components were 1,8-cineol (69.45%), <em>α–</em>pinene (14.26%), globulol (4.02%) and terpinen-4-ol (1.79%). Yield of the essential oil of <em>E. torquata</em> was 1.2% (v/w) and, twenty components were identified which the main compounds were 1,8-cineol (33.86%), α–pinene (26.14%), aromadendrene (8.99%) and globulol (7.28%). The essential oil yield of <em>E. loxophleba </em>was 1.54% (v/w) which the major components were identified including 1,8-cineol (25.71%), globulol (21.63%), aromadendrene (20.43%) and 4-metyl-2-pentyl acetate (14/98%). The highest amount of terpenoides in essential oil of leaves <em>E. largiflorens, E. intertexta, </em>and<em> E. torquata</em> were monoterpenes, while the highest amount of terpenoides in essential oil of <em>E. loxophleba</em> were sesquiterpenes. Industrial and practical recommendations: According to the results of this research and the value of different species of medicinal <em>Eucalyptus</em> L'Her essential oils (in particular, the combination of 1,8-cineol), cultivation and exploitation of <em>E</em>.<em> intertexta</em> for pharmaceutical industry is recommended.