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.     

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.     

Oxepane diterpenoids sesquiterpene lactones from ‘zoapatle’ (montanoa tomentosa), a mexican plant with oxytocic activity

Investigation of the ‘tea’ prepared from the leaves of ‘zoapatle’ (Montanoa tomentosa), resulted in the isolation of the known biologically active oxepane diterpenoids zoapatanol and montanol, the known sesquiterpene lactones zoapatanolide A, C and D as well as two new biologically active oxepane diterpenoids and a new sesquiterpene lactone. The structures of the new compounds were established by spectroscopic methods.     

Neue sesquiterpenlactone und thymol-derivate aus Inula-arten

The investigation of three Inula species affords, besides known compounds, two new sesquiterpene lactones and two new thymol derivatives. The chemotaxonomic situation in this genus is still very complicated.     

Melampolides and other germacranolides from Blainvillea dichotoma

The aerial parts of Blainvillea dichotoma afforded, in addition to known compounds, seven new sesquiterpene lactones, four related to elephantin, two melampolides and a further cis,cis-germacranolide. The chemotaxonomic situation is discussed briefly.     

Guaianolides from Ainsliaea fragrans

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

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.     

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.     

Über einen neuen sesquiterpentyp aus Senecio oxyriifolius

The roots of Senecio oxyriifolius contain a new tricyclic sesquiterpene with a new carbon skeleton, probably formed from α-humulene, and two bisabolene derivatives. The structures were elucidated by spectroscopic methods and some chemical transformations.     

Three furanoheliangolides from Calea villosa

Calea villosa afforded three new sesquiterpene lactones, two furanoheliangolides and an epoxy- germacranolide, as well as several known compounds. The structures were elucidated by spectroscopic methods.     

Sesquiterpenes from Japanese liverworts

Five Japanese liverworts (Bazzania sp.) were examined for sesquiterpenes. B. japonica and B. pompeana contained two new drimane-type sesquiterpene esters, albicanyl 3,4-dihydroxycinnamate and albicanyl 2,4dihydroxycinnamate. Tridensenone, a new aromadendrane-type sesquiterpene ketone was isolated from B. tridens. The stereostructures of these new sesquiterpenes were elucidated mainly by spectrometry. Barbatane-, bazzanane- and cuparane-type sesquiterpenes were found in all of the five species investigated. These sesquiterpenes, along with the new drimane- and aromadendrane-type sesquiterpenes are useful chemosystematic markers.     

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.     

β-Isocomen,ein neues sesquiterpen aus Berkheya-arten

The investigation of several Berkheya species afforded in addition to already known compounds three unusual sesquiterpene hydrocarbons. Together with modhephene and isocomene, a new one is present, its structure being elucidated by spectroscopic methods and by some chemical transformations. All 18 species investigated contain the typical thiophene derivatives, isolated earlier; the patterns of compounds present divide the species into two groups.     

Sesquiterpene alcohols from Artemisia pygmaea

Artemisia pygmaea Gray contains two sesquiterpene alcohols: the known cryptomeridiol (I) and pygmol (II), a new compound. No sesquiterpene lactones were found in the plant although other species of the section Tridentatae Rydb., with which A. pygmaea has been classified, are usually rich in lactones.     

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 germacranolides and four eudesmanolides from Tithonia rotundifolia

The aerial parts of Tithionia rotundifolia afforded, in addition to two known sesquiterpene lactones, eleven new ones, seven germacranolides and four eudesmanolides. The structures were determined by ¹H NMR spectroscopy.     

Germacranolides,a guaianolide with a β-lactone ring and further constituents from Grazielia species

An investigation of three Grazielia species afforded, in addition to known compounds, several new sesquiterpene lactones, eight germacranolides, two melampolides and one guaianolide as well as three diterpenes, two geranylgeraniol derivatives and a labda-diene. Three of the sesquiterpene lactones had an additional β-lactone ring, one an acid function, and two others unusual ester functions. The structures were elucidated by spectroscopic methods and some chemical transformations. The chemotaxonomic situation is discussed briefly.     

Deltoidin A and B,two new germacrolides from Eupatorium deltoideum

Investigation of E. deltoideum provided two new germacrolide-type sesquiterpene lactones, deltoidin A and B, besides the known guaianolide ligustrin, and diterpenes and triterpenes.     

Jinkohol,a prezizane sesquiterpene alcohol from agarwood

A new tricyclic sesquiterpene, jinkohol, has been isolated from an agarwood (Aquillaria sp.) which is different from that obtained from Aquillaria agallocha. Its structure was shown to be 2β-hydroxy-(+)-prezizane by spectroscopic methods and by chemical transformation. The two kinds of agarwood are readily identified from their sesquiterpene components.