Search results for "Terpene"
showing 10 items of 816 documents
Chemical composition of the essential oils fromEriocephalus africanus L. var.africanus populations growing in Spain
2007
Essential oils from the aerial parts of three Eriocephalus africanus L. var. africanus populations were analysed by means of GC–FID and GC–MS. Sixty-one constituents were identified, representing more than 96% of the total oil composition. Artemisia ketone (56.46–56.58%), intermedeol (9.19–11.63%) and γ-eudesmol (4.26–5.64%) were the main compounds. Application of the Pearson correlation coefficient showed high similarity between the nine samples analysed. Copyright © 2007 John Wiley & Sons, Ltd.
Ucriol, an epoxy-diterpene from Sideritis syriaca
1983
Abstract The isolation of a new epoxy-diterpene from the inflorescence of Sideritis syriaca (S. sicula Ucria) is described. Its structure and stereochemistry were established by spectroscopy and partial synthesis.
Sesquiterpene lactones and acetylenes from Artemisia reptans
1994
Abstract The aerial parts of Artemisia reptans yielded a new thiophene acetylene, four new guaianolides, a new acyclic sesquiterpene related to davanone and several known compounds.
Spirocurcasone, a diterpenoid with a novel carbon skeleton from Jatropha curcas.
2010
Spirocurcasone (14), a diterpenoid possessing the unprecedented "spirorhamnofolane" skeleton, was isolated from the root barks of Jatropha curcas, a plant extensively cultivated throughout the world, along with 11 known and two other new diterpenoids. The stereostructure of spirocurcasone was established using HRESIMS, NMR, and quantum mechanical calculation of the electronic circular dichroic (ECD) spectrum. Some of the isolated diterpenoids showed a potent activity against L5178Y, a mouse lymphoma cell line.
Antifeedant activity of neo-clerodane diterpenoids from Teucrium fruticans and derivatives of fruticolone
1999
The antifeedant activity of three neo-clerodane diterpenoids, fruticolone, isofruticolone and fruticolide from Teucrium fruticans was assessed using larvae of Spodoptera littoralis. Isofruticolone was one of the most potent of the Teucrium derived neo-clerodanes. Chemical modification of functional groups on fruticolone showed that its activity could be enhanced.
Caryophyllene derivatives from Pulicaria dysenterica
1992
Abstract A reinvestigation of the aerial parts of Pulicaria dysenterica has allowed the isolation of six new caryophyllene derivatives and 12 known ones. 13 C NMR data of all these derivatives are reported.
Induction of cryptic metabolites of the endophytic fungus Trichocladium sp. through OSMAC and co-cultivation
2019
The endophytic fungus Trichocladium sp. isolated from roots of Houttuynia cordata was cultured on solid rice medium, yielding a new amidepsine derivative (1) and a new reduced spiro azaphilone derivative (3) together with eight known compounds (4–11). Co-cultivation of Trichocladium sp. with Bacillus subtilis resulted in induction of a further new compound (2) and a 10-fold increase of 11 compared to the axenic fungal culture. Moreover, when the fungus was cultivated on peas instead of rice, a new sesquiterpene derivative (13) and two known compounds (12 and 14) were obtained. Addition of 2% tryptophan to rice medium led to the isolation of a new bismacrolactone (15). The structures of the …
Germacrane esters from roots of Ligularia persica
1991
Abstract Extraction of roots of Ligularia persica and chromatographic separation yielded one new derivative of tovarol, four new derivatives of shiromodiol, α- and β-eudesmol, bakkenolide A and four known eremophilane derivatives.
Artalbic acid, a sesquiterpene with an unusual skeleton from Artemisia alba (Asteraceae) from Sicily
2011
Abstract From the aerial parts of Artemisia alba (Asteraceae) artalbic acid ( 1 ), a sesquiterpene with an unusual skeleton, was isolated. Its structure was elucidated on the basis of extensive proton, 13 C and two-dimensional NMR experiments, as well as by transformation in its methyl ester derivative.
The C-12 and C-20 configurations of some neo-clerodane diterpenoids isolated from Teucrium species
1986
Abstract A convenient and conclusive method for determining the C-12 stereochemistry of neo-clerodan-20,12-olide derivatives, even when only one epimer is available, is by 1H NMR NOE measurements. The C-12 configuration of 26 neo-clerodane diterpenoids isolated from Teucrium species has been re-examined by using this type of experiment. The results indicated that all the previous assignments were correct, except for teupyreinin, where the previously assigned C-12(S) configuration must be amended to C-12(R). This was confirmed by chemical transformations and additional 1H and 13C NMR studies. Furthermore, the NOE experiments allowed the assignment of a C-20(S) configuration for teuflavin, th…