Sesquiterpene lactones from Inezia integrifolia

Inezia integrifolia afforded, in addition to known compounds, three new eudesmanolides and a guaianolide. Two of the eudesmanolides were obtained as a mixture. The relative position of the ester groups could not be determined with certainty. The chemotaxonomy is discussed briefly.     

Sesquiterpene lactones from Lactuca sativa

The aerial parts of Lactuca sativa afforded lactucin, 1 11β,13-dihydrolactucin, lactupicrin, a new melampolide and 3β,14-dihydroxy-11β,13-dihydrocostunolide.     

Sesquiterpene lactones from Calea leptocephala

Chemical analysis of Calea leptocephala yielded seven sesquiterpene lactones three of which had not been previously reported as natural products. The new compounds were represented by a furanoheliangolide, 8β-angeloyloxy-9α-acetoxycalyculatolide, the germacranolide desacetylcalein A, and a guaianolide, 8β-angeloyloxyleptocephalide. The structures of the new compounds were established by spectroscopic methods.     

Sesquiterpene lactones from Achillea micrantha

The aerial parts of Achillea micrantha afforded the eudesmanolides santamarin, reynosin, dihydrosantamarin, dihydroerynosin and the germacranolides artemorin, gallicin, dihydroparthenolide as well as a new one, dihydroparthenolide bisepoxide. The structures were elucidated by spectroscopic data.     

Sesquiterpene lactones from Carphochaete bigelovii

Five sesquiterpene lactones with C₁₀-diester side-chains have been identified as major constituents of a leaf surface extract of Carphochaete bigelovii. The structures were elucidated by spectroscopic methods and are reported for the first time. Chemosystematic implications are discussed briefly.     

Sesquiterpene lactones from Viguiera hypargyrea

The new sesquiterpene lactones 8β-[epoxyangeloyloxy]-14-hydroxytithifolin and 8-[epoxyangeloyl]-14-acetoxy-eupatolide, were isolated from Viguiera hypargyrea. The structures were established by chemical and spectroscopic means. The chemotaxonomic implications of the chemical constituents of Viguiera are briefly discussed.     

Sesquiterpene lactones from Centaurea tweediei

Aerial parts of Centaurea tweediei from Argentina afforded as the main constituent the sesquiterpene lactone onopordopicrin and minor amounts of a new heliangolide, a new guaianolide, a new eudesmanolide, a new eudesmane acid and the lignans arctigenin and matairesinol.     

Sesquiterpene lactones from leucanthemopsis pulverulenta

From Leucanthemopsis pulverulenta, two guaianolides, 8α-hydroxyestafiatin and epiligustrin, and one 4,5-cis-germacranolide, named pulverulide, have been isolated. Epiligustrin and pulverulide are new natural compounds.     

Sesquiterpene lactones from Centaurea arbutifolia

The investigation of the aerial parts of Centaurea arbutifolia afforded four new sesquiterpene lactones; two germacranolides and two elemanolides, plus aguerin A. Their structures were elucidated by spectroscopic methods and by partial synthesis.     

Sesquiterpene lactones from Centaurea species

The investigation of further Centaurea species gave, in addition to known compounds, one new sesquiterpene lactone, 11β, 15-dihydroxysaussurea lactone, of the elemanolide type.     

Sesquiterpene lactones from Helianthus grosseserratus

The isolation is reported of six new sesquiterpene lactones based on the eudesmanolide, trans, trans-germacradienolide and heliangolide skeletons from Helianthus grosseserratus Martens. The diterpenes grandifloric, 17-hydroxy-ent-isokaur-15-enic and ciliaric acids and the flavones hispidulin and pectolinarigenin were also found.     

Sesquiterpene lactones from Inula cappa

Three new germacranolides, ineupatolides A–C (1–3), together with six known sesquiterpenoids, were isolated from the aerial parts of Inula cappa (Buch.-Ham.) DC. The structures of new compounds were elucidated by 1D-, and 2D-NMR techniques including HMQC, HMBC, ¹H–¹H COSY and ROESY spectra. The known compounds were identified by spectroscopic data analyses and data comparison. Compound 2 was finally proved to be converted from 1 with the trace existence of acid. Compounds 2 and 5 showed moderate inhibitory activity against human leukemia cell line HL-60, while compounds 2, 5, 6, 7 and 9 exhibited no antiproliferative activities on human lung cancer cell line A549.     

Sesquiterpene lactones from Brachylaena species

The investigation of two Brachylaena species afforded in addition to known sesquiterpene lactones and other constituents five new lactones, a germacranolide, a guaianolide and three eudesmanolides. The structures were elucidated by spectroscopic methods. The chemotaxonomy of this complex genus is discussed.     

Sesquiterpene lactones from Chrysanthemum coronarium

The flower heads of Chrysanthemum coronarium afforded a new sesquiterpene lactone, dihydrocumambrin A, in addition to the known cumambrin A.     

Sesquiterpene lactones from Syncretocarpus sericeus

The aerial parts of Syncretocarpus sericeus afforded in addition to known compounds a new heliangolide. The chemistry supports the placement of thi     

Sesquiterpene lactones from pyrethrum flowers

Three new sesquiterpene lactones of the germacranolide-type [(11R)-11,13-dihydrotatridin-A, (11R)-11,13-dihydrotatridin-B and (11R)-6-O     

Sesquiterpene lactones from Tithonia rotundifolia

A chemical investigation of Tithonia rotundifolia afforded seven new sesquiterpene lactones in addition to three known ones. The structures of the new compounds 3-acetyl-15-hydroxyleptocarpin, 15-hydroxyleptocarpin and tirotundifolins A, B, C, D and E were established by spectroscopic and chemical means.     

Sesquiterpene lactones from Artemisia maritima

Two new sesquiterpene lactones have been isolated from Artemisia maritima and the structures have been assigned on the basis of their spectral properties as 1-oxo-6β,7α,11βH,14β-methylgermacra-4(5)-ene-12,6-olide and 1-oxo-6β,7α,11βH-germacra-4(5),10(14)-dien-12,6-olide.