New sesquiterpene lactones and other constituents from Fitchia speciosa

The investigation of Fitchia speciosa afforded, in addition to known compounds, three new sesquiterpene lactones, iso-β-costal, two p-hydroxyacetophenone derivatives and an isoeugenol derivative. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation in this complicated genus is discussed.     

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 and other constituents from Schistostephium species

From four Schistostephium species, in addition to known compounds, 43 new ones were isolated, three isocomene, two bisabolene, two eudesmane, two allo-himachalene and two nerolidol derivatives, two sesquiterpenes with a new carbon skeleton derived from isocomene, nine eudesmanolides, 20 6,12- and 8,12-germacranolides respectively, and a prostaglandin-like acid. The structures were elucidated by spectroscopic methods, especially high field ¹H NMR and some chemical transformations. The stereochemistry of some 8,12-germacranolides was established by partial synthesis which required revision of the previous assignments of the configuration of inunolide, its 4,5- and 1,10-epoxide, vernudifloride, simsiolide, 6-hydroxy-1,10-epoxyinunolide and perhaps also of tanachin. The chemotaxonomic situation is discussed briefly.     

Sesquiterpene lactones of eupatorium anomalum and eupatorium mohrii

Several new guaianolides and the previously known heliangolide eurecurvin have been isolated from Eupatorium anomalum. Eupatorium mohrii also yielded three of the new guaianolides together with eurecurvin and a new germacradienolide. The implications of these findings are discussed.     

Sesquiterpene lactones from Sonchus macrocarpus

Eight sesquiterpene lactones were isolated from the roots of Sonchus macrocarpus. The eudesmanolides 15-hydroxy-4β, 15-dihydroreynosin and 15-hydroxy-4β, 15, 11β, 13-tetrahydroreynosin were isolated for the first time.     

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 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 solstitialis

Eight sesquiterpene lactones were isolated from Centaurea solstitialis (yellow starthistle). They are solstitialin A, repin, subluteolide, acroptilin, janerin, cynaropicrin, and the new lactones solstitiolide and episolstitiolide.     

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.     

Four guaianolides and other constituents from three kaunia species*

The investigation of three species of the new genus Kaunia afforded four new guaianolides and four thymol derivatives. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly.     

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 sesquiterpene lactones from Ferreyanthus species

The investigation of two Ferreyanthus species afforded seven germacranolides which have not been isolated previously. Two derivatives of linalol were also present. The structures were elucidated by spectroscopic methods. Chemotaxonomic relationships are briefly discussed.     

Acanthospermolides and other constituents from Blainvillea acmella

The aerial parts of Blainvillea acmella afforded, in addition to widespread triterpenes, desacetyl ovatifolin, desacyl grazielic acid tiglate, 8β-[2-methylbutyryloxy]-9β-hydroxy-14-oxo-acanthospermolide, four new germacranolides and seven acanthospermolides. The roots gave ovatifolin, two widespread thiophenacetylenes and two daucane derivatives. Comparison of the data with those of cyclochaenin required a revision of its structure. The structures were elucidated by high field ¹H NMR spectroscopy. Biogenetic relationships and taxonomic aspects are discussed briefly.     

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     

New melampolides,kaurene derivatives and other constituents from Ichthyothere species

The reinvestigation of Ichthyothere terminalis afforded, in addition to known compounds, two new melampolides, a hydroxy borneol, a pinene derivati     

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.     

Heliangolides and other constituents from Bejaranoa semistriata

The investigation of Bejaranoa semistriata, a new genus in the tribe Eupatorieae, afforded in addition to known compounds a new furanoheliangolide, two epimeric 1-keto-heliangolides, two germacranolides, two nerolidol derivatives and a geranylnerol derivative. The structures were elucidated by spectroscopic methods and a few chemical transformations.     

Sesquiterpene lactones of Eupatorium scabridum

Eupatorium scabridum, a hybrid biotype presumed to arise by hybridization of E. rotundifolium and E. semiserratum furnished anti-tumor sesquiterpene lactones characteristic of the putative parents.     

Sesquiterpene lactones from Ambrosia maritima (Damssissa)

Six sesquiterpene lactones were isolated from the aerial parts of Ambrosia maritima. Four pseudoguaianolides were isolated for the first time in addition to parthenin and neoambrosin.