Nasser A. Awadh Ali, Stefania Zanetti, Bruno Marongiu, , Alessandra Piras, Silvia Porcedda, Danilo Falconieri, Paola Molicotti, Essential oil composition of leaves of Stachys yemenensis obtained by supercritical CO2 . Natural Product Research: Formerly Natural Product Letters Volume 24, Issue 19, 2010

This article reports the composition of the essential oil from the leaves of Stachys yemenensis. The essential oil was extracted by supercritical CO2 (90 bar; 40°C) and its chemical composition was determined by gas chromatography and gas chromatography–mass spectrometry. The major components of the sample were α-phellandrene (13.9%), β-phellandrene (11.7%), elemol (12.0%), spathulenol (6.7%), β-eudesmol (5.0%), α-eudesmol (4.75%) and squalene (4.8%). On the exhausted matrix, deprived of the volatiles, we carried out a high-pressure (250 bar) treatment for the extraction of squalene (49.7%). The antimicrobial activity of the essential oils has been assayed by using the broth dilution method on two American Type Culture Collection (ATCC) strains, Escherichia coli ATCC 35218 and Staphylococcus aureus ATCC 43300, and two clinical strains, Candida albicans and Candida glabrata.


L. Quassinti, G. Lupidi, F. Maggi, G. Sagratini, F. Papa, S. Vittori, A. Bianco, M. Bramucci. Antioxidant and antiproliferative activity of Hypericum hircinum L. subsp. majus (Aiton) N. Robson essential oil. Natural Product Research, 05/04/2012

This study was undertaken to assess the antioxidant and antiproliferative potential of the essential oil of Hypericum hircinum L. subsp. majus (Aiton) N. Robson. Analysis of the oil composition revealed that sesquiterpene hydrocarbons (69.3%) dominate, cis-β-guaiene, δ-selinene and (E)-caryophyllene being the most representative. Significant values of antioxidant activity were found using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radical scavenging assays. The essential oil revealed antiproliferative activity as evaluated on human glioblastoma (T98G), human prostatic adenocarcinoma (PC3), human squamous carcinoma (A431) and mouse melanoma (B16-F1) tumour cell lines by MTT assay.