title: Essential oil composition of leaves of Stachys yemenensis obtained by supercritical CO₂.
abstract: 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.
authors.affiliation: Department of Pharmacognosy, Sana'a University, Sana'a, Yemen.
authors.forename: Nasser A Awadh
authors.initials: NA
authors.lastname: Ali
authors.forename: Bruno
authors.initials: B
authors.lastname: Marongiu
authors.forename: Alessandra
authors.initials: A
authors.lastname: Piras
authors.forename: Silvia
authors.initials: S
authors.lastname: Porcedda
authors.forename: Danilo
authors.initials: D
authors.lastname: Falconieri
authors.forename: Paola
authors.initials: P
authors.lastname: Molicotti
authors.forename: Stefania
authors.initials: S
authors.lastname: Zanetti
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D041221:Candida glabrata / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D009822:Oils, Volatile / Q000737:chemistry* / Q000494:pharmacology*; D018515:Plant Leaves / Q000737:chemistry*; D012717:Sesquiterpenes / Q000737:chemistry; D013185:Squalene / Q000737:chemistry; D031366:Stachys / Q000737:chemistry*; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D009822:Oils, Volatile; D012717:Sesquiterpenes; D013185:Squalene; C013258:spathulenol; C033011:elemol