Search results for "germacranolide"
showing 10 items of 17 documents
Structure-Activity Relationships of Cytotoxic Lactones as Inhibitors and Mechanisms of Action.
2020
Background: Some lactones prevent protein Myb-dependent gene expression. Objective: The object is to calculate inhibitors of Myb-brought genetic manifestation. Methods: Linear quantitative structure–potency relations result expanded, among sesquiterpene lactones of a variety of macrocycles (pseudoguaianolides, guaianolides, eudesmanolides and germacranolides), to establish which part of the molecule constitutes their pharmacophore, and predict their inhibitory potency on Myb-reliant genetic manifestation, which may result helpful as leads for antileukaemic therapies with a new mechanism of action. Results: Several count indices are connected with structure–activity. The α-methylene-γ-lacto…
Germacranolides and a monoterpene cyclic peroxide from Artemisia fragrans
1998
Abstract The aerial parts of Artemisia fragrans collected in Armenia yielded a new cyclic monoterpene peroxide with the irregular santolinyl framework, together with several known germacranolides. Comparison with previously published chemical results suggests these may actually have been performed on a different, although closely related species.
Influence of conformational factors on acid-catalyzed cyclizations of germacranolides: Molecular structure of the cyclization products of gallicin an…
1995
Acid-catalyzed cyclization of the natural germacranolide gallicin (8) yielded, among other products, the 1,4-epoxyeudes-manolide 9, which has a trans-fused decaline system. Under the same conditions the closely related germacranolide shonachalin A (8α-hydroxygallicin) (3) cyclized to the eudesmanolide 4 with a cis fused decaline system. The structures of these cyclization products were secured by means of chemical correlations and X-ray diffraction analyses.
Lipase-catalysed preparation of acyl derivatives of the germacranolide cnicin
2009
Several acyl derivatives of cnicin were obtained through lipase-catalysed acylation and alcoholysis reactions. In most reactions lipases showed a regioselective behaviour affording only one product. Longer chain acyl derivatives were prepared at lower temperature than the used in lipase-catalysed reactions, to preclude side products formation. The enzymatic approach let to prepare a family of novel acetyl and fatty acid derivatives of cnicin which are not obtainable following traditional organic synthetic procedures. Fil: Monsalve, Leandro Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Unidad de Microanálisis…
Sesquiterpene lactones from Picris echioides
1992
Abstract The aerial parts of Picris echioides yielded the new germacranolide 3β-hydroxybalchanolide and the known guaianolides hieracin I, hieracin II, 8-deoxylactucin, jacquilenin and 11 -epijacquilenin.
Sesquiterpene lactones from Artemisia species
1993
Abstract The aerial parts of Artemisia spicigera yielded two new eudesmanolides as well as three known ones. The aerial parts of Artemisia verlotiorum yielded four known germacranolides and two known eudesmanolides.
Sesquiterpene lactones from Artemisia herba-alba
1990
Abstract The aerial parts of Artemisia herba-alba subsp. valentine yielded, in addition to known compounds, a new germacranolide, six new eudesmanolides and ilicic acid methyl ester.
Sesquiterpene lactones and lignans from Centaurea species
1992
Abstract The aerial parts of Centaurea calcitrapa yielded cnicin, cnicin 4′-acetate, melitensin, a related elemanolide, the two new germacranolides 11α,13- and 11β,13-dihydrosalonitenolide, and the lignans arctigenin, pinoresinol and 7′( S )-hydroxyarctigenin. The latter compound is described for the first time as a natural product. The aerial parts of Centaurea pabotii yielded 11,13-dihydrodeacylcynaropicrin, aguerin A and a new guaianolide related to cynaropicrin.
Acid rearrangment of epoxy-germacranolides and absolute configuration of 1beta, 10alpha-epoxy-salonitenolide
2010
The acid-catalyzed cyclization of mono epoxides of cnicin acetonide (3) was investigated. Several 6,12-eudesmanolides were obtained, and their stereochemistry established by extensive spectroscopic analyses. Chemical correlations also led to the assignment of the absolute configuration of 1beta,10alpha-epoxy-salonitenolide (13), a previously isolated natural product. The cytotoxic activities of some compounds were determined against A549 and MCF-7 tumor cell lines. The esterified germacranolides 2-6 were selectively cytotoxic against the MCF-7 breast cancer cell line.
Sesquiterpene lactones from Artemisia lucentica
1997
Abstract The aerial parts of Artemisia lucentica yielded, in addition to several known compounds, a bicyclic monoterpene ketone, two germacranolides, an eudesmanolide, a 10- epi neudesmanolide, a 2-norelemanolide and three bisabolene derivatives. The stereochemistry of a germacranolide, described as 2α-hydroxyartemorin in a previous investigation of the species, has now been corrected and the compound has been renamed lucentolide.