Browsing by Author "Salgueiro, L. R."
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- Analysis by gas chromatography-mass spectrometry of the volatile components of Teucrium lusitanicum and Teucrium algarbiensisPublication . Cavaleiro, C.; Salgueiro, L. R.; Miguel, Maria Graça; Da Cunha, A. P.The essential oils from four samples of Teucrium lusitanicum and one sample of Teucrium algarbiensis, grown in Algarve (southern Portugal) were analyzed by gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). Seventy-one volatile compounds were identified. Major compounds of T. algarbiensis oil were alpha-pinene (8.3%), sabinene (7.2%), beta-pinene (10.2%), limonene (11.8%) and germacrene D (7.6%). Concerning T. lusitanicum, some quantitative differences were found with regards to the major constituents of the oils from four populations: alpha-pinene (0.8-8.5%), sabinene (2.1-9.6%), beta-pinene (2.5-11.9%), limonene (1.2-11.5%) and elemol (2.6-12.0%). (C) 2004 Elsevier B.V. All rights reserved.
- Antimicrobial activity of the essential oils of Dittrichia viscosa subsp viscosa on Helicobacter pyloriPublication . Silva, D.; Denham, E.; Faleiro, Leonor; Miguel, Maria Graça; Cavaleiro, C.; Salgueiro, L. R.Dittrichia viscosa subsp. viscosa (Compositae) is found on edges, wood clearings and in waste places of the Iberian Peninsula. Aerial parts of D. viscosa were collected at flowering phase in September-October 2001 around Lisbon, Portugal and the essential oils isolated by hydro-distillation for 4 h using a Clevenger-type apparatus. The oils were analyzed by gas chromatography and gas chromatography-mass spectrometry. Preliminary examination of the essential oils allowed the identification of 32 components. Only four components reached percentages over 5%: fokienol (11.8%), T-muurorol (7.9%), (E)-nerolidol (5.5%) and delta-cadinene (5.0%). The essential oils were tested against Helicobacterpylori and Listeria monocytogenes. Essential oils did not have antimicrobial activity against L. monocytogenes. The essential oil at 0.88 to 22.22 mu g.ml(-1) did not inhibit the growth of H. pylori, affected the growth slightly at 44.40 mu g.ml(-1), and completely inhibited the growth at 88.80 to 133.20 mu g.ml(-1) Results show that use of D. viscosa essential oil in the treatment of gastric disorders caused by H. pylori can be effective.
- Portuguese thymbra and thymus Species volatiles: Chemical composition and biological activitiesPublication . Figueiredo, A. C.; Barroso, J. G.; Pedro, L. G.; Salgueiro, L. R.; Miguel, Maria Graça; Faleiro, LeonorThymbra capitata and Thymus species are commonly known in Portugal as thyme and they are currently used as culinary herbs, as well as for ornamental, aromatizing and traditional medicinal purposes. The present work reports on the state of the art on the information available on the taxonomy, ethnobotany, cell and molecular biology of the Portuguese representatives of these genera and on the chemotaxonomy and antibacterial, antifungal and antioxidant activities of their essential oils and other volatile-containing extracts.
- Susceptibility of Helicobacter pylori to essential oil of Dittrichia viscosa subsp revolutaPublication . Miguel, Maria Graça; Faleiro, Leonor; Cavaleiro, C.; Salgueiro, L. R.; Casanova, J.The essential oil of Dittrichia viscosa subsp. revoluta and its fractions were assessed for anti-Helicobacter activity. The essential oil was isolated by hydrodistillation, submitted to flash column chromatography and analysed by gas chromatography, gas-chromatography coupled to mass spectrometry and C-13-nuclear magnetic resonance. The anti-Helicobacter activity was determined by incorporation of the crude essential oil and oxygenated fractions of the oil into the culture medium. At a concentration of 0.025 mu L/mL no recovery was registered when one of the oxygenated fractions of the oil, mainly constituted by 3-methoxy cuminyl isobutyrate (about 40%), was used. This fraction revealed a higher activity against the six H. pylori strains tested when compared with the other oxygenated fractions. The crude essential oil at a concentration of 0.33 mu L/mL reduced the initial population of H. pylori CCUG 15818 of 8.52 +/- 0.30 log(10) cfu/mL to 7.67 +/- 0.22 log(10) cfu/mL. The susceptibility of several Helicobacter pylori strains to the oxygenated fraction of Dittrichia viscosa subsp. revoluta essential oil suggests the possible use of these natural products in combating this widespread infection. Copyright (C) 2007 John Wiley & Sons, Ltd.