Pungent sesquiterpene lactones of the european liverworts Chiloscyphus polyanthus and Diplophyllum albicans

The characteristic pungency of the European liverwort, Chiloscyphus polyanthus, is due to a mixture of four sesquiterpene lactones, two new structures ent-5β-hydroxydiplophyllin and ent-3-oxodiplophyllin, and the previously known diplophyllin and diplophyllolide. A new dihydrodiplophyllin, together with the pungent diplophyllolide and diplophyllin, has been isolated from Diplophyllum albicans. Ent-dihydrodiplophyllolides derived from the above pungent diplophyllolides produce intense numbness of the tongue. All pungent sesquiterpene lactones showed inhibitory activity towards the germination and root elongation of rice husks.     

Anticancer sesquiterpene lactones of Michelia compressa (magnoliaceae)

Investigation of the cytotoxic active components of Michelia compressa afforded two new cytotoxic sesquiterpene lactones, michelenolide and micheliolide. Parthenolide, costunolide, santamarine, reynosin and liriodenine were also isolated and exhibited cytotoxic activity. The known sesquiterpene lactones, lanuginolide and dihydroparthenolide, were isolated but were not active. Two other new inactive sesquiterpene lactones, compressanolide and dihydroreynosin, were also obtained. The structures of michelenolide and micheliolide were confirmed by partial synthesis from parthenolide and the structure of compressanolide by partial synthesis from dihydroparthenolide.     

Sesquiterpenes from pernettya furens

The novel sesquiterpene carboxylic acids, pernetic acid A-E, a new sesquiterpene alcohol pernetol, a new sesquiterpene aldehyde, pernetal, and pernetic acid A methyl ester, were isolated from the aerial parts of Pernettya furens. The structures were established by spectral and X-ray analysis. Pernetic acids D and E have a novel cis hydrindane skeleton presuming the oxidative modification from the cadalane skeleton.     

Sesquiterpene Glucosides from Chloranthus japonicus Sieb

A new lindenane sesquiterpene glucoside named yinxiancaoside A (1), a new, rare bidesmosidic megastigmane sesquiterpene glucoside named yinxiancaoside B (5), and three known sesquiterpene glucosides, chloranoside A (2), pisumionoside (3), and sarcaglaboside A (4), were isolated from the whole plant of Chloranthus japonicus Sieb. The structures of the new compounds were established by an extensive study of their spectral data, especially 1D- and 2D-NMR. The cytotoxic activity of the isolated compounds against human hepatoma (Hepg-2), human ovarian carcinoma (OV420), and human breast cancer (MCF-7) cells was investigated.     

Confertdiolide,a novel sesquiterpenoid lactone from Parthenium

Four sesquiterpene lactones were isolated from several populations of Parthenium confertum var. lyratum (Gray) collected in Sierra de Arteaga, southern Coahuila. Three of the compounds, hysterin, tetraneurin E and hymenin were previously isolated from other Parthenium species. The fourth constituent is the new cyclopropanoid sesquiterpene dilactone confertdiolide which represents a new structural type. The photolytic conversion of hymenin into confertdiolide confirmed its structure.     

Guaianolide α-arabinopyranosides from Helenium amarum

The aerial parts of Helenium amarum afforded, in addition to compounds reported previously, several known sesquiterpene lactones as well as some new ones, two pseudoguaianolides and a complex mixture of guaianolide α-arabinopyranosides, which differed in the position of the double bond, the configuration at C-8 and the position of an acetate group in the sugar moiety. Furthermore seco-caryophyllenes and phenylpropane derivatives were isolated. The structures were elucidated by spectroscopic methods and few chemical transformations.     

α-Humulene derivatives including a sesquiterpene acid with a rearranged carbon skeleton from Lychophorora columnaris

An investigation of Lychnophora columnaris afforded in addition to known compounds six new α-humulene derivatives and a rearranged sesquiterpene with a new carbon skeleton. These compounds and several sesquiterpene lactones isolated from this species seem to be of chemotaxonomic importance. The structures were elucidated by spectroscopic methods and a few chemical transformations including partial synthesis.     

A guaianolide alloside and other constituents from Picris kamtschatica

From Picris kamtschatica two new guaianolide glycosides, including a beta-allopyranosyl analogue of ixerin F, were isolated, in addition to ten known sesquiterpene lactones and six phenolic compounds. This is the first time a sesquiterpene lactone alloside has been described from plants. The compounds were characterized based on mass, 1D and 2D NMR spectral data.     

Glaucolides from Vernonia fulta

Four sesquiterpene lactones were isolated from the aerial parts of Vernonia fulta. Spectral characterization showed that three were new and one was known (i.e. glaucolide-B). The biogenetic relationship among these sesquiterpene lactones is discussed briefly.     

Guaianolides from Cichorium intybus and structure revision of Cichorium sesquiterpene lactones

The isolation and structure elucidation of a new lactucopicrin derivative from Cichorium intybus is described, together with the revised structures of several sesquiterpene lactones previously isolated from Cichorium species. The known eudesmanolide magnolialide and the known guaianolide ixerisoside D, reported for the first time from the plant material, along with the previously known chicory sesquiterpene lactones have been also isolated and identified.     

Sesquiterpenoids from the endophytic fungus Trichoderma sp. PR-35 of Paeonia delavayi

A new bisabolane-type sesquiterpene, trichoderic acid (1), and a new acorane-type sesquiterpene, 2β-hydroxytrichoacorenol (2), along with three known compounds, cyclonerodiol (3), cyclonerodiol oxide (4), and sorbicillin (5), were isolated from the culture broth of Trichoderma sp. PR-35, an endophytic fungus isolated from Paeonia delavayi. Their structures were elucidated on the basis of their IR, MS, and 1D- and 2D-NMR analyses. The antibacterial and antifungal activities of 1-5 towards various types of bacteria and fungi were tested. Most of the compounds showed moderate or weak antimicrobial activities in an agar-diffusion assay.     

An unusual acenaphthylene-type sesquiterpene hydrocarbon from Siam and Sumatra benzoin gum

A new sesquiterpene was isolated from extracts of Sumatra benzoin gum. Its structure was elucidated by means of mass spectrometry and two-dimensional NMR. This new compound presented an acenaphthylene-type skeleton unpreviously described among the family of sesquiterpene hydrocarbons.     

Allenic germacranolides,bourbonene derived lactones and other constituents from Vernonia species

An investigation of seven Vernonia species, mainly from northern Brazil, afforded in addition to known compounds three new unusual sesquiterpene lactones with an allenic group. Intensive NMR studies fully established the structures. Furthermore, two lactones derived from bourbonene, two new glaucolides, a new furansesquiterpene, a nerolidol derivative and two other sesquiterpenes derived from eudesmane were isolated. The biogenetic relationships of the sesquiterpene lactones present in Veronia species as well as the chemotaxonomic aspects are discussed.     

Seven guaianolides from Eupatorium chinense

Two allyl hydroperoxy guaianolide sesquiterpene lactones (peroxyeupahakonin-A and -B) and five new guaianolides (eupahakonin-A and -B, eupahakonenin-A and -B, and eupahakonesin) were isolated from E. chinense and characterized. The allyl hydroperoxy sesquiterpene lactones were characterized by spectral and chemical methods. They were prepared chemically by photosensitized oxygenation of eupahakonin-A.     

Guaianolides from Ainsliaea fragrans

Five sesquiterpene lactones were isolated from Ainsliaea fragrans, two of them being new.     

Three bourbonenolides and other sesquiterpene lactones from two vernonia species

A re-investigation of V. arkansana afforded several new sesquiterpene lactones, three bourbonenolides, obviously closely related to those isolated from this plant previously, a glaucolide and a methoxy derivative most probably formed by fragmentation of the corresponding bourbonenolide. From V. profuga in addition to known lactones a new guaianolide was isolated. The biogenetic relationships of the Vernonia sesquiterpene lactones are discussed briefly.     

Weitere isocedren-derivate aus Trixis paradoxa

The investigation of two further species from the tribe Mutisieae afforded in addition to known compounds three new sesquiterpene lactones and two further sesquiterpene esters, all closely related to compounds isolated before from other Trixis species. The isolation of these new substances from Trixis further establishes the chemotaxonomic situation in the subtribe Nassauviinae. From the Dinoseris species, among others, 1β-hydroxyalantolactone was isolated, indicating a relationship to the subtribe Gochnatiinae.     

The Structures of Triptotetraolide and Wilforjine

A new diterpenoid lactone named triptotetraolide and a new sesquiterpene alkaloid named wilforjine were isolated from Tripterygium wilfordii Hook. f.. Their structures were elucidated on the basis of UV, IR, 1H-NMR, 13C-NMR, MS and X-ray analysis.     

Sesquiterpene lactones from Anthemis carpatica Willd

Four new eudesmanolides and two new guaianolides were isolated from the aerial parts of Anthemis carpatica Willd. and their structures elucidated by spectral methods. In addition, seven known sesquiterpene lactones were identified.     

11β,13-Dihydroguaianolides from Artemisia douglasiana and a thiophene acetylene from A. schmidtiana

The aerial parts of Artemisia douglasiana afforded, in addition to some known sesquiterpene lactones, 22 new closely related guaianolides. A new thiophene acetylene was isolated from the aerial parts of A. schmidtiana together with some known sesquiterpene lactones. The structures were elucidated by high field ¹H NMR spectroscopy.