Four guaianolides,a eudesmanolide and a germacranolide from Ursinia saxatilis

An investigation of Ursinia saxatilis afforded in addition to known compounds a new eudesmanolide derived from ursialpinolide, a germacranolide rel     

A further steiractinolide derivative from Spilanthes leiocarpa

The aerial parts of Spilanthes leiocarpa afforded, in addition to known compounds, a new eudesmanolide as well as two elemanolides which have both been isolated previously. Careful ¹H NMR investigation showed that the configuration of one of these isomeric lactones has to be corrected.     

Eudesmanolide from Centaurea granata

Investigation of the aerial parts of Centaurea granata afforded, in addition to two known polymethoxylated flavones, a new eudesmanolide. The structure of the new compound was elucidated by spectroscopic methods as 8α-hydroxy-11β,13-dihydro onopordaldehyde.     

Eudesmanolides from Calea trichomata

Chemical analysis of Calea trichomata yielded, besides four known eudesmanolides, a new eudesmanolide, trichomatolide A. The structure of the new compound was established by chemical and spectral methods.     

Stereochemistry of chapliatrin and its congeners from Liatris gracilis

Re-examination of Liatris gracilis afforded the known sesquiterpene lactones chapliatrin, isochapliatrin, acetlisochapliatrin, five new closely related 5,10-epoxygermacranolides and a new eudesmanolide. The stereochemistry of the 5,10-epoxygermacranolides has been settled by an X-ray analysis of isochapliatrin.     

New germacranolides and other constituents from Trichogoniopsis morii

Trichogoniopsis morii afforded, in addition to known compounds, a new toxol derivative, two diterpenes, a labdane and an ent-kaurane derivative, an eudesmanolide and five germacranolides, a furanoheliangolide and four 1-oxo-germacranolides. The structures were elucidated by spectroscopic methods and a few chemical transformations. The chemotaxonomy of the genus Trichogoniopsis is discussed briefly.     

Sesquiterpene lactones from Mikania species

The aerial parts of Mikania guaco afforded in addition to a known eudesmanolide three new ones. The aerial parts of M. vitifolia gave two guaianolides, both being 3-chlorodehydroleudocin derivatives and a seco-germacranolide related to pycnolide. The structures were elucidated by highfield NMR techniques. The proposed position of the hydroxyl group in a chloroguaianolide from a Lasiolaena species has to be revised.     

New germacranolides and other sesquiterpene lactones from Dicoma species

Two subspecies of Dicoma anomala afforded, in addition to known compounds, an eudesmanolide, a guaianolide and four germacranolides, the latter being closely related 8, 12-lactones. D. schinzii gave three new germacranolides and D. zeyheri a pair of isomeric acetylenic compounds. The structures were elucidated by highfield ¹H NMR spectroscopy. The chemotaxonomic situation of this genus is discussed briefly.     

Chlorantholides A–F,eudesmane-type sesquiterpene lactones from Chloranthus elatior

Six eudesmane-type sesquiterpene lactones, named chlorantholides A–F, were isolated from the ethanol extract of Chloranthus elatior (Chloranthaceae) together with 12 known compounds. Their structures were elucidated on the basis of extensive spectroscopic analysis, and their absolute configurations were studied by the CD exciton chirality method. The structure of a recently reported eudesmanolide from Chloranthus anhuiensis: 8β-hydroxy-1-oxoeudesma-3,7(11)-dien-12,8-olide, was also revised as 8β-hydroxy-2-oxoeudesma-3,7(11)-dien-12,8-olide (chlorantholide D).     

Sesquiterpenlacton-β-d-glucopyranoside sowie ein neues eudesmanolid aus Taraxacum officinale

The investigation of the roots and the aerial parts of Taraxacum officinale afforded, in addition to known compounds, a new eudesmanolide, a tetrahydroridentin B, a eudesmanolide-β-d-glucopyranoside and two germacranolide acids, which are esterified with β-d-glucose. The latter two seem to represent a new type of sesquiterpene lactone. All three of the new glucose derivatives have a strong bitter taste. The structures were elucidated by intensive NMR studies and by some chemical transformations.     

Neuartige sesquiterpenlactone und neue acetylenverbingen aus Athanasia-arten

The investigation of two further South African Athanasia-species afforded, in addition to known compounds, sixteen new ones, ten guaianolides, an eudesmanolide, three sesquiterpenes, a new enediynene and a phenylpropane derivative. The structures were elucidated by extensive NMR-studies. Three of the lactones are very unusual in having an endoperoxide bridge; their structures, however, were elucidated only indirectly. These further chemical results on Athanasia again add support to the idea that these species might be better placed in the genus Pentzia.     

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.     

Neue sesquiterpenlactone und nerolidol-derivate aus Ursinia-arten

The aerial parts of U. anethoides afforded, in addition to new nerolidol derivatives, a new germacranolide. The structure could only be elucidated by formation of the corresponding pyrazoline derivative and by comparison of the ¹H NMR data with those of similar pyrazolines. The aerial parts of U. alpina also contain a new nerolidol derivative and, in addition to the known 9β-hydroxycostunolide, a new eudesmanolide. The roots of all species contain furanosesquiterpenes, which are also present in related genera.     

New germacranolides from Inula heterolepis

The aerial parts of Inula heterolepis afforded two new germacranolides and a new eudesmanolide, all closely related to haageanolide, which was also isolated.     

A Eudesmanolide and a guaianolide from Cyathocline purpurea

Two new sesquiterpene lactones, the eudesmanolide, isoivangustin, and the guaianolide, 6α-hydroxy-4(14),10(15)-guaianadien-8α,12-olide, have been isolated from Cyathocline purpurea.     

Ridentin-β: An eudesmanolide from Artemisia tripartita ssp. rupicola

Ridentin-B (I), a new eudesmanolide, has been isolated from Artemisia tripartite ssp. rupicola. It is biosynthetically closely allied with ridentin (IV), a germacronolide. The stereochemistry of ridentin is discussed.     

New sesquiterpene lactones from Liriodendron tulipifera

Four new sesquiterpene lactones were obtained from L. tulipifera; two germacranolides, lipiferolide (4) and epitulipinolide diepoxide (5) from the leaves, an elemanolide, epitulipdienolide (7), and an eudesmanolide, γ-liriodenolide (6) from the root bark. Structural determination was by physical and chemical methods and by direct correlation to the known epitulipinolide (3). Lipiferolide and epitulipinolide diepoxide possess cytotoxic activity against KB cells.     

Artegallin,a sesquiterpene lactone from Artemisia caerulescens subsp. gallica

Four eudesmanolides were isolated from Artemisia caerulescens subsp. gallica. The constitution and stereochemistry of the new eudesmanolide artegallin were determined on the basis of its spectroscopic properties and by transformation into β-santonin.     

New sesquiterpene lactones from Inula oculus-christi L.

Investigation of the aerial parts of Inula oculus-christi L. led to the identification of four new sesquiterpene lactones: an eudesmanolide (4α,15α-epoxypulchellin E) and three guaianolides (2α-acetoxy-4α,9β-dihydroxy-1β-guaia-11(13),10(14)-dien-12,8α-olide, 9β,10β-epoxygaillardin, 9α,10α-epoxy-2-epi-gaillardin), in addition to the known gaillardin, pulchellin E, pulchellin C and 3-O-palmitates of 16β-hydroxylupeol, 16β-hydroxy-β-amyrin, and faradiol. The structures of all compounds have been elucidated on the basis of their spectral data.     

Arbusculin-D from Artemisia arbuscula ssp. Arbuscula

Abstract-Arbusculin-D (I), a new eudesmanolide, has been isolated from Artemisia arbuscula Nutt. ssp. arbuscula and is present also in A. arbuscula Nutt. ssp. thermopola Beetle. It represents a structural variant in the lactone grouping.