Search results for "centaurea"
showing 10 items of 89 documents
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)
Two guaianolides from Centaurea collina
1987
Abstract Two guaianolides isolated from the aerial parts of Centaurea collina were identified as 3β-hydroxy-8α-epoxymethylacriloiloxy-4(15),10(14),11(13 and its 11β,13-dihydro derivative by spectroscopic methods.
Sesquiterpene lactones, flavonoids and coumarins from Centaurea collina
1989
Abstract The isolation and characterization of two coumarins, five flavonoids and four sesquiterpene lactones from the aerial parts of Centaurea collina are reported. The 13 C NMR data are included.
New Sesquiterpene Lactones and Other Constituents fromCentaurea paui
1997
Aerial parts of Centaurea paui afforded, in addition to several known sesquiterpene lactones, the two new elemanolides 2–4, the new elemane derivative 5 as well as the five new heliangolides 14–18. Their structures were elucidated by spectroscopic methods, especially high-field NMR spectroscopy. The structure of the heliangolide 12 previously isolated from this plant, has been confirmed by X-ray diffraction.