Search results for "Sesquiterpene"
showing 10 items of 236 documents
Influence of Feeding and Oviposition by Phytophagous Pentatomids on Photosynthesis of Herbaceous Plants
2010
Abstract Feeding by herbivorous insects may change photosynthetic activity of host plants. We studied how feeding and oviposition by herbivorous stink bugs, Murgantia histrionica and Nezara viridula (Heteroptera: Pentatomidae), affect photosynthetic parameters of Brassica oleracea (savoy cabbage) and Phaseolus vulgaris (French bean). First, we measured photosynthetic gas exchange, chlorophyll fluorescence imaging, and emission of induced volatile organic compounds (VOC) immediately after feeding and during a post-feeding period. Photosynthesis decreased rapidly and substantially in B. oleracea and P. vulgaris infested by feeding bugs. Stomatal conductance did not decrease proportionally wit…
Up-regulation of an N-terminal truncated 3-hydroxy-3-methylglutaryl CoA reductase enhances production of essential oils and sterols in transgenic Lav…
2007
Spike lavender (Lavandula latifolia) essential oil is widely used in the perfume, cosmetic, flavouring and pharmaceutical industries. Thus, modifications of yield and composition of this essential oil by genetic engineering should have important scientific and commercial applications. We generated transgenic spike lavender plants expressing the Arabidopsis thaliana HMG1 cDNA, encoding the catalytic domain of 3-hydroxy-3-methylglutaryl CoA reductase (HMGR1S), a key enzyme of the mevalonic acid (MVA) pathway. Transgenic T0 plants accumulated significantly more essential oil constituents as compared to controls (up to 2.1- and 1.8-fold in leaves and flowers, respectively). Enhanced expression …
Identification of volatile synomones, induced by Nezara viridula feeding and oviposition on bean spp., that attract the egg parasitoid Trissolcus bas…
2004
Bean plants ( Vicia faba L. and Phaseolus vulgaris L.) damaged by feeding activity of Nezara viridula (L.) ( Heteroptera: Pentatomidae), and onto which an egg mass had been laid, produced volatiles that attracted the egg parasitoid Trissolcus basalis (Wollaston) (Hymenoptera: Scelionidae). Extracts of volatiles of broad bean and French bean plants induced by adults of N. viridula as a result of their feeding activity, oviposition activity, and feeding and oviposition activity combined were analyzed by gas chromatography-mass spectrometry (GC-MS), and tested in Y-tube olfactometer bioassays as attractants for T. basalis females. In extracts from undamaged leguminous plants, green-leaf volati…
Chemotaxonomic value of the essential oil compounds in species of Teucrium pumilum aggregate
2000
Volatile compounds from the aerial parts of Teucrium lepicephalum Pau and Teucrium carolipaui C. Vicioso ex Pau, both belonging to the Teucrium pumilum aggregate, were analysed by capillary GC and GC-MS. From the common and specific compounds (mono- and sesquiterpenes) of the two taxa, chemical characterization was carried out and taxonomic relationships were assessed. Application of the cluster and k-means discriminant analysis shows a differential chemical relationship between T. lepicephalum and Teucrium carolipaui.
Volatile components from flower-heads of Centaurea nicaeensis All., C. parlatoris Helder and C. solstitialis L. ssp. schouwii (DC.) Dostál growing wi…
2008
The volatile constituents of the flowerheads of Centaurea nicaeensis All., C. parlatoris Helder and C. solstitialis L. ssp. schouwii (DC.) Dostal were extracted by hydrodistillation and analysed by GC and GC-MS. Altogether 113 components were identified. Fatty acids and hydrocarbons were the most abundant components in the oils. Caryophyllene and caryophyllene oxide were the main compounds of the sesquiterpene fraction. The study on the biological activity of the oils shows no significant activity.
Volatile compounds of flowers and leaves of Sideritis italica (Miller)Greuter et Burdet (Lamiaceae), a plant used as mountain tea
2010
Sideritis italica (Miller) Greuter et Burdet (Lamiaceae), widely used in ethnopharmacological medicine, occurs in Southern Italy and Sicily. The phytochemical composition of the essential oils of S. italica flowers and leaves, harvested in Piano Battaglia (Sicily), was analysed by GC and GC-MS. Of the 51 compounds, 43 in the oil from flowers and 29 in the oil from leaves were identified. Kaur-15-ene (20.0%) was recognised as the main constituent of the oil from flowers, together with beta-cubebene (12.1%), beta-pinene (8.5%), (Z)-nuciferol (6.5%), tricyclene (4.5%) and alpha-bisabolol (4.0%). In the oil from leaves, p-methoxyacetophenone (26.0%) prevailed, as did hexadecanoic acid (21.3%), …
Chemical composition of the essential oil of Salvia microstegia Boiss. et Balansa growing wild in Lebanon.
2005
The essential oil of aerial parts of Salvia microstegia Boiss. et Balansa (Lamiaceae) growing wild in Lebanon was obtained by hydrodistillation and was analysed by GC and GC–MS. 70 compounds, representing 94.0% of the oil, were identified. The major components were caryophyllene oxide (6.2%), pulegone (5.7%), 4-vinylguaiacole (5.3%), hexadecanoic acid (5.1%) and menthone (4.9%). © 2006 Elsevier B.V. All rights reserved.
GC and GC–MS analysis of the essential oil of Nepeta cilicica Boiss. ex Benth. from Lebanon
2013
The hydrodistillation of the aerial parts of Nepeta cilicica Boiss. ex Benth., collected in Lebanon in the Horsh Ehden reserve, yielded 0.13% (w/w) of essential oil. Gas chromatography (GC) and GC-mass spectroscopy analysis enabled the identification of 75 compounds representing 96.8% of the total oil. The most abundant compounds were spathulenol (15.1%), hexadecanoic acid (14%), δ-cadinene (5.5%) and α-copaene (4.5%). On the whole, the oil was constituted mainly by sesquiterpenes (45.9%), among which sesquiterpene hydrocarbons (27.6%) slightly prevailed over oxygenated sesquiterpenes (18.3%).
Essential oil analysis ofTeucrium libanitisandT. turredanumby GC and GC-MS
2003
The chemical composition of the six essential oils obtained from Teucrium libanitis and Teucrium turredanum collected at different localities was analysed by GC and GC–MS. Fifty-three constituents were identified. The oil of T. libanitis is characterized by the monoterpene α-pinene (9.9–21.2%) and the sesquiterpene δ-cadinene (5.3–9.7%), while that of T. turredanum had a higher content of sesquiterpenoids: β-caryophyllene (15.6–32.6%), α-humulene (4.7–10.1%) and β-bisabolol (6.4–8.3%), and a lower percentage of monoterpenoids (<1%). A multivariate procedure (hierarchical clustering) for detecting natural grouping established that T. libanitis and T. turredanum constitute two independent taxa…
Application of Cell Culture for the Production of Bioactive Compounds from Sponges: Synthesis of Avarol by Primmorphs from Dysidea avara
2000
Among all metazoan phyla, sponges are known to produce the largest number of bioactive compounds. However, until now, only one compound, arabinofuranosyladenine, has been approved for application in humans. One major obstacle is the limited availability of larger quantities of defined sponge starting material. Recently, we introduced the in vitro culture of primmorphs from Suberites domuncula, which contain proliferating cells. Now we have established the primmorph culture also from the marine sponge Dysidea avara and demonstrate that this special form of sponge cell aggregates produces avarol, a sesquiterpenoid hydroquinone, known to display strong cytostatic activity especially against ma…