Search results for "Centaur"
showing 10 items of 105 documents
Volatile components of Centaurea calcitrapa L. and Centaurea sphaerocephala L. ssp. sphaerocephala, two Asteraceae growing wild in Sicily
2006
The volatile components of the flowerheads of Centaurea calcitrapa L. (C.c.) and Centaurea sphaerocephala L. ssp. sphaerocephala (C.s.) were obtained by hydrodistillation and identified by GC and GC–MS. Altogether 96 components were identified, 66 in C. calcitrapa and 68 in C. spaerocephala, mostly fatty acids (32.8%, C.c. and 44.2%, C.s.) and hydrocarbons (32.3%, C.c. and 15.9%, C.s.). 9,12-Octadecadienoic acid (15.8%, C.c.) and hexadecanoic acid (30.7%, C.s.) were the most abundant fatty acids; tricosane (8.0%, C.c.) and heptacosane (4.9%, C.s.) were the main hydrocarbons. Sesquiterpenes were also present as hydrocarbons (10.1% for 14 components in C.c. and 9.2% for 13 components in C.s.)…
Essential oil from the aerial parts of Centaurea cuneifolia Sibth. & Sm. and C. euxina Velen., two species growing wild in Bulgaria
2009
Abstract The volatile constituents of the aerial parts of Centaurea cuneifolia Sibth. & Sm. and Centaurea euxina Velen. from Bulgaria were extracted by hydrodistillation and were analyzed. The main components in C. cuneifolia were β-eudesmol (26.5%) and hexadecanoic acid (17.6%). The main components in C. euxina were hexadecanoic acid (20.3%), spathulenol (10.8%) and caryophyllene oxide (6.2%). The chemotaxonomic significances with respect to other previously studied species of the same sections ( Achrolopus and Phalolepis , respectively) are discussed.
Typification of two Linnaean names: Centaurea aspera and Centaurea isnardii (Asteraceae)
2014
The typification of the names Centaurea aspera L. and C. isnardii L. (Asteraceae) is discussed. A lectotype for C. aspera is designated from original material conserved in UPS-BURSER (Joachim Burser Herbarium). Centaurea isnardii is typified by an illustration of Isnard (1719) confirming this name as a synonym of C. aspera subsp. aspera.
Volatile constituents of aerial parts of three endemicCentaureaspecies from Turkey:Centaurea amanicolaHub.-Mor.,CentaureaconsanguineaDC. andCentaurea…
2008
The volatile constituents of the aerial parts of Centaurea amanicola Hub.-Mor., Centaurea consanguinea DC. and Centaurea ptosimopappa Hayek were extracted by hydrodistillation and analysed by GC and GC–MS. Altogether 94 components were identified. Sesquiterpenoids, fatty acids and carbonylic compounds were the most abundant components in the oils. Hexadecanoic acid and (Z,Z )-9,12-octadecadienoic acid were the main fatty acids in all the examined samples, that showed different patterns of composition. The study on the biological activity of the oils showed an action mainly against the Gram-positive pathogens.
Norisoprenoids from Centaurea aspera and C. salmantica
1993
Abstract From aerial parts of Centaurea aspera var. subinermis a new homoderivative of the grasshopper ketone has been isolated. Its structure was deter
Volatile components ofCentaurea cineraria L. subsp.umbrosa (Lacaita) Pign. andCentaurea napifolia L. (Asteraceae), two species growing wild in Sicily
2003
The volatile components of the flowerheads of Centaurea cineraria L. subsp. umbrosa (Lacaita) Pign. and Centaurea napifolia L. were obtained by hydrodistillation and identified by GC and GC-MS. Altogether 55 components were identified, mostly sesquiterpenes and hydrocarbons. Copyright © 2003 John Wiley & Sons, Ltd.
A novel germacranolide-aminoacid adduct dimer from centaurea aspera
1991
Abstract The novel germacronolide-valine adduct dimer 1 has been isolated from aerial parts of Centaurea aspera var. aspera . Its structure has been determined by spectroscopic methods.
Sesquiterpene lactones from Centaurea sphaerocephala ssp. sphaerocephala
1994
Abstract Aerial parts of Centaurea sphaerocephala ssp. sphaerocephala furnished sesquiterpene lactones commonly found in Centaurea species as well as a new germacranolide and a new elemadienolide.
Flavones, sesquiterpene lactones and glycosides isolated from Centaurea aspera var. Stenophylla
1984
Abstract From the alcoholic extract of Centaurea aspera var. stenophylla benzoic acid, p-hydroxybenzoic acid, apigenin, 6-methoxyluteolin, 11,13-dehydromelitensin, melitensin, stenophyliolide, ethyl-7-O-apigenin-glucuronate and the glucosides of sitosterol and stigmasterol were isolated and characterized. Stenophyllolide was shown to be 9,15-dihydroxygermacra-1(10),4,11-trien-12,6-olide.
Rearrangement of Germacranolides. Synthesis and Absolute Configuration of Elemane and Heliangolane Derivatives from Cnicin
2003
A study of the Cope rearrangement of 15-oxo-germacranolides to 15-oxo-elemanolides has been carried out. The synthesis of two natural elemanolides, isolated from Centaurea paui, and an efficent isomerization of the C-4/C-5 double bond of 15-oxo-germacranolides to form heliangolides are reported. The absolute configuration of all the compounds has been ascertained. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)