Extraction of Juniperus communis L. ssp. nana Willd. essential oil by supercritical carbon dioxide

Marongiu B;PORCEDDA, SILVIA;PIRAS, ALESSANDRA;SANNA, GIUSEPPINA;Mureddu M;LODDO, ROBERTA

2006-01-01

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Abstract

Isolation of essential oil from dried leaves, berries and wood of Juniperus communis L. ssp. nana were obtained with two different methods: by means of the classical hydrodistillation (HD) and by using carbon dioxide in the supercritical state (SFE). Operative conditions adopted in SFE were: pressure, 90 bar; temperature, 50 °C. The leaf essential oil was made up of limonene (36.2%), β-selinene (15.2%) and α-terpinyl acetate (5.3%). The berry oil was composed chiefly of: limonene (40.1%), germacrene D (17.2%) and α-pinene (4.7%). The oil derived from the wood mainly consisted of. limonene (8.9%), α-terpinyl acetate (9.7%) and germacrene D (8.6%). The yields (w/w) were 0.78%, 0.70% and 0.12% for leaves, berries and wood, respectively. The essential oil obtained by hydrodistillation did not differ very much in composition but their yields were lower than those mentioned above. On the matrices exhausted owing to a SFE at 90 bar, two further extractions at 50 °C and at higher pressure (200 and 300 bar) were performed in succession in order to obtain a mixture of compounds with higher molecular weight. The extract obtained at 200 bar on a charge of leaves inhibited the proliferation of cell derived from haematological and solid human tumours, showing the same potency and selectivity as etoposide and proving to be 8-100-fold more potent than 6-MP.