1,720,977 research outputs found
Volatiles from leaves, fruits, and virgin oil from Olea europaea Cv. Olivastra Seggianese from Italy
No full textThe volatiles produced by leaves and fruits of Olea europaea cv. Olivastra Seggianese have been analyzed in two different phenological stages. Furthermore, the volatiles of the virgin olive oil obtained from ripe fruits has been characterized. The volatiles were sampled by means of two different techniques: hydrodistillation and SPME. Differences were observed between the two different collection times, the different organs, and sampling techniques. The major constituents were often aldehydes, particularly (E)-2-hexenal (9.8-48.0%); however, also many terpenoids have been identified, mainly (E,E)-R-farnesene (0.2-27.0%), linalool (0-3.6%), â-caryophyllene (0-8.1%), and valencene (0-2.5%). This is the first investigation on this cultiva
Essential oils of Galeopsis pubescens and G. tetrahit from Tuscany (Italy)
No full textThe essential oils obtained from the flowering aerial parts of Galeopsis pubescens and G. tetrahit growing on Monte Amiata (Italy) have been studied. Sesquiterpenes were the main constituents of both essential oils (88.9% and 90.4%, respectively); the major compounds were germacrene D and bicyclogermacrene (about 60% and 6%, respectively). The differences between the two essential oils were mostly quantitative and were referred mainly to β-caryophyllene (5.7% and 2.1%, respectively) and (E)-β-farnesene (1.1% and 5.6%). This is the first report about the composition of essential oils from this genu
Chemical composition of the essential oil from Jasminum pubescens (Retz.) Willd. (Oleaceae) leaves and flowers
No full textThe essential oil obtained from the leaves and flowers of Jasminum pubescens (Retz.) Willd. (Oleaceae) has been analyzed by GC/MS. Sixty-three and sixty-four components of the essential oils, representing 95.0% of the total oil for the leaves and 91.9% for the flowers, were identified, resp. Both the oils were mainly constituted by non-terpene derivs. (58.2% and 50.8%, resp.), among which aldehydes (44.7%) characterized the essential oil from the leaves. Besides aldehydes (14.3%) and other carbonylic compds. (acids, esters, and ketones, 38.1%) were the main non-terpene compds. of the oil from the flowers
ATTIVITA’ REPELLENTE DEI PRINCIPALI COMPONENTI DELL’OLIO ESSENZIALE DI HYPTIS SUAVEOLENS NEI CONFRONTI DI SITOPHILUS GRANARIUS
No full textFlower buds and seeds essential oils of Panax notoginseng (Burk.) F.H. Chen (Araliaceae)
No full textThe essential oils obtained from flowers buds and seeds of Panax notoginseng (Burk.) F.H. Chen (Araliaceae) have been analyzed by GC (FID) and GC/MS. Thirty components of the oil of the flower buds, representing 93.6%, and sixteen components of the seeds oil, representing 96.5%, were identified, resp. The main constituents were sesiquiterpenes: spathulenol, germacrene D, bicyclogermacrene, and α-panasinsene. A comparison between constituents of the seed and flower bud oils with those reported in the literature for other Panax ssp. revealed some chemotaxonomic considerations
A xanthone from Senecio mikanioides leaves
No full textA new p-hydroxybenzoylated xanthone, muraxanthone, and 4 known xanthones were isolated from leaves of S. mikanioides (cuttings collected from Cape Town, South Africa, and grown in Italy). The structure of the new compound was determined from spectral dat
Antimicrobial activity of the essential oil of Calamintha nepeta and its constituent pulegone against bacteria and fungi
No full textThe chemical composition of the essential oil of Calamintha nepeta and its antimicrobial activity against Listeria monocytogenes, Bacillus cereus, Salmonella veneziana, S. paratyphi B. S. typhimurium, Fusarium moniliforme, Botrytis cinerea, Aspergillus niger and Pyricularia oryzae have been studied. Moreover the main constituents of the oil (limonene, menthone, pulegone, menthol) have been tested against the same microorganisms. Only pulegone showed antimicrobial activity, particularly against all the Salmonella specie
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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