1,721,014 research outputs found
Supercritical fluid extraction and fractionation of essential oils and related products from natural matrices
No full text
A comparative study of thermodynamic properties of binary mixtures containing alkynes
No full textLiterature data on molar excess enthalpies (H-E) and molar excess Gibbs energies (G(E)) of linear alkynes + n-alkanes, cycloalkanes, benzene or tetrachloromethane are treated in the framework of DISQUAC, an extended quasichemical group-contribution theory. The systems are characterized by three types of contact surfaces: acetylenic (Cequivalent toC group), aliphatic (CH3 or CH2 groups), cycloaliphatic (c-CH2 group), aromatic (C6H6 group) and chlorine (CCl4 group). Using a limited number of adjusted contact interchange energies parameters, the model provides a fairly consistent description of the thermodynamic properties as a function of concentration. The model may serve to predict missing data. (C) 2004 Elsevier B.V. All rights reserved
Chemical variability in essential oils from Ruta species among seasons, and its taxonomic and ecological significance
No full textLeaf essential oils of 11 samples from Ruta montana, Ruta chalepensis subsp. latifolia and Ruta chalepensis subsp. angustifolia collected from two sites have been studied by GC/MS that allowed to identify 22, 25 and 12 components, respectively. The variability in the composition of essential oils among species and seasons was very high, and hence the existence of different chemotypes has been inferred. The major components were 2-undecanone, (E) caryophyllene, 2-nonanone and 2-methyloctyl acetate. Multivariate analysis of the 11 samples suggest that the main factors capable to influence the chemical composition of leaf essential oils was both the collection period and the geographical origin. 2-Undecanone seems to be the chemotaxonomic marker of Ruta genus. Furthermore, the formation of distinct clusters and sub-clusters at high distance also supports that the patterns of distribution of chemical constituents among seasons can be used in delimiting species and infraspecific taxa within the species complexes
A Preliminary Investigation on Smokeless Tobacco Use and Its Cognitive Effects Among Athletes
Full text linkIntroduction: Among athletes, an increasing use of nicotine via smokeless tobacco has been reported. However, there are currently unanswered questions about whether the use by athletes is due to nicotine’s addictive properties and/or to benefits in physical and cognitive performance (e.g., decision-making). In this original article we reported about, (i) snus-induced reinforcing effects among snus-user athletes (Survey) and (ii) the effects of snus on the Iowa Gambling Task (IGT) in snus-user skiers (Experimental study). IGT is an experimental neuropsychological task that has been previously used on athletes and addicts to test decision-making.Methods: Survey: data were collected with the modified Cigarette Evaluation Questionnaire (mCEQ) that was administered to 61 winter sport athlete snus-users in Northern Italy. Experimental study: IGT data included: amount of money earned, number of choices from advantageous and disadvantageous decks and overall net score. Eighteen male snus-users were tested under satiety or after 12-h abstinence conditions according to a crossover design.Results: Survey: the comparison between occasional vs. regular snus-users showed a statistically significant difference in satisfaction (P = 0.0088), calm (P = 0.0252), and enjoyment (P = 0.0001) mCEQ items suggesting a snus intake/effect relationship. Experimental study: significantly higher IGT net scores were found during the first 20 choice cards after abstinence vs. satiety conditions (P = 0.0024).Conclusion: In the Survey, regular snus use induces greater satisfaction and psychological reward than occasional use. In the Experimental study, snus intake might produce an early and transient cognitive improvement on IGT in abstinent snus-users, presumably acting as a withdrawal relief
May essential oil of a native species inhibit seed germination of the invasive Acacia saligna?
Full text linkInvasive Alien Species (IAS) are considered, after habitat loss and fragmentation, as one of the greatest threats to the conservation of native biodiversity and natural ecosystems worldwide. Acacia saligna (Labill.) H.L.Wendl. (Fabaceae) is native of South-Western Australia, but has been planted extensively in many areas of the world, among which the Mediterranean Region, becoming highly invasive especially in coastal habitats. In the Mediterranean ecosystems, several autochthonous species produce essential oils (EOs), in different concentrations in several parts of the plant, as adaptation to harsh environments. The ecological role of these compounds, named allelochemicals, may determine a positive influence and/or negative against other target organisms. The aim of this work was to test if the EO of Rosmarinus officinalis L. (Lamiaceae), perennial aromatic dwarf-shrub of the Mediterranean area, may be an effective method to inhibit the seed germination of the alien invasive A. saligna. In particular, variability in seed germination requirements and responses among populations from Sardinia and Sicily (Italy) were evaluated. Germination tests under light (12 hours of irradiance per day), constant temperatures (10, 15, 20°C) and several concentrations of R. officinalis EO (3.9, 7.8, 15.6 μl/ml) were carried out. Moreover, the ability of A. saligna seeds to recover their germination after the EO exposure was evaluated washing seeds with Tween 80 or sodium hypochlorite solutions. Among the examined factors, only the EO concentration and temperature had highly significant effect on seed germination. The lowest EO concentration did not show differences respect to the control (0 μl/ml), while the highest concentration inhibited significantly seed germination of all populations at all the tested temperatures. No seed recovered the ability to germinate after the EO exposure with none of the two methods of washing. Our results allowed to identify the minimum concentration of EO of an autochthonous species such as R. officinalis, able to inhibit the seed germination of the invasive A. saligna. In conclusion, these results may be useful to the biological control against the invasive alien species to allow the conservation of native biodiversity and the preservation of the Mediterranean habitats
Characterization of Essential Oils from Different Taxa Belonging to the Genus Teucrium in Sardinia Island, Italy
Full text linkThe genus Teucrium L. (Lamiaceae) is a genus growing in mild climate zones, particularly in the Mediterranean Basin and Central Asia. It is represented by 11 taxa in Sardinia (Italy), living commonly in sunny habitats. In this study, the following eight Sardinian Teucrium taxa were selected, and the essential oils (EOs), obtained by stem distillation, were analyzed by GC–FID and GC–MS: T. capitatum subsp. capitatum, T. chamaedrys subsp. chamaedrys, T. flavum subsp. glaucum, T. marum, T. massiliense, T. scordium subsp. scordioides, T. scorodonia, and T. subspinosum. The comprehensive analyses led to the identification of 87 constituents representing the majority of the volatile compounds. Significant differences, both qualitative and quantitative, were observed between the taxa. Overall, monoterpenes and sesquiterpenes characterized all Teucrium EOs: T. capitatum subsp. capitatum and T. flavum subsp. glaucum revealed the highest content of monoterpene hydrocarbons, while in the other Teucrium taxa sesquiterpene hydrocarbons prevailed. Worthy of note, diterpenes were found only in T. marum and T. subspinosum, whereas T. massiliense was rich in non-terpenic oxygenated compounds. To the best of our knowledge, this is the first comprehensive report on the chemical composition of EOs obtained from Sardinian Teucrium species
Biological activity evaluation of the oils from Laurus nobilis of Tunisia and Algeria extracted by supercritical carbon dioxide
No full textChemical composition and biological activity of volatile extracts from leaves and fruits of Schinus terebinthifolius Raddi from Tunisia
No full textVolatile oils composition from leaves and ripe fruits of pink pepper (Schinus terebinthifolius Raddi) growing in Tunisia were investigated using GC-FID and GC-MS techniques. Volatile oil extraction was achieved by hydrodistillation (HD) using a Clevenger apparatus and by supercritical fluid extraction (SFE) using carbon dioxide. All plant organs, gave SFE extracts chiefly composed by α-pinene, α-phellandrene, β-phellandrene, germacrene D and bicyclogermacrene. In the case of the fruits, both extraction techniques gave volatile oils of similar composition; whereas the comparison between the HD and SFE leave oils revealed important differences in the content of α-pinene (6.1 % vs traces), α-phellandrene (22.7 % vs 0.8 %) and β-phellandrene (14.6 % vs 1.2 %). All volatile samples were evaluated against yeasts and dermatophyte strains, being more active against Cryptococcus neoformans, particularly the volatile oil from the fruits, with MIC values of (0.32-0.64) mg/mL. Moreover, this oil revealed an inhibitory effect on germ tube formation in C. albicans at sub-inhibitory concentration. At the concentration of MIC/8 the inhibition of filamentation was more than 70 %
Antiviral activity of some aromatic and medicinal plants against RNA virus: preliminary study
No full textPlant products provide alternative and successful source of lead compounds for pharmaceutical industry.
The present study was aimed to evaluate, in cell-based assays, the antiviral properties of various kinds of essential oils obtained from plants that commonly grow in Sardinia, against a broad spectrum of RNA viruses.
Essential oils of Helichrisum italicum ssp. microphyllum, Laurus nobilis L., Mirtus communis L., Pistacia lentiscus L., Rosmarinus officinalis L., Salvia officinalis L. and Satureja thymbra L., were extracted by hydrodistillation and analysed by GC-MS.
Interestingly, the essential oil of Salvia officinalis showed moderate activity (EC50 of 54 μM) against bovine viral diarrhoea virus (BVDV), an enveloped RNA virus belonging to the Flaviviridae family that has often been used as a surrogate model for the hepatitis C virus. BVDV is responsible for several clinical manifestations in bovines, including respiratory, gastroenteric and reproductive diseases.
With the aim to individuate the compounds responsible of the biological activity under examination, the major components of the oil, camphene, -pinene, limonene, 1,8-cineole, cis-thujone, camphor, (E)-caryophyllene and -humulene were tested. -Humulene resulted active against BVDV as essential oil, with fair EC50 of 40 μM
- …
