Neue guajanolide aus Lasthenia-arten

The investigation of two species of Lasthenia afforded two new guaianolides and a new bisabolone derivative, in addition to already known compounds. The presence of an eremophilenic acid in these plants is remarkable. The results are discussed chemotaxonomically, since the tribal position of this genus is still debated.     

Neue C10-säureamide,furanoeremophilane und andere inhaltsstoffe aus bolivianischen Senecio-arten

The investigation of seven Bolivian Senecio species afforded in addition to known compounds five new furanoeremophilanes, two C₁₀-amides, a new isoeugenol ester and the isomer of pterophorin. The structures are elucidated mainly by spectroscopic methods. While most of the new compounds are closely related to those isolated before from Senecio species, four of them are unusual. Another is a new type of a furanoeremophilane; its biogenesis however, can be explained easily from known types.     

Einige neue furanoeremophilane aus Senecio-Arten

The investigation of two varieties of the South African S. hypochoerideus affords, besides known compounds, six new furanoeremophilanes and a pimarene-derivative. By contrast, S. greyi has yielded two further new furanoeremophilanes and a new eremophilene. These structures are elucidated mainly by spectroscopic methods. Chemotaxonomic aspects are briefly discussed.     

New labdane derivatives and further constituents of Brickellia species

The investigation of several Brickellia species and two further related species afford besides known compounds four new labdane derivatives, a new acetylenic carbinol and a new dihydrobenzofuran derivative. The structures have been elucidated by spectroscopic methods. The chemotaxonomic aspects are discussed briefly.     

Weitere bisabolen-derivate und andere inhaltsstoffe aus südafrikanischen Senecio-arten

The investigation of additional Senecio species afforded five new bisabolene derivatives, two acetylenic compounds and two aromatic compounds,     

Neue sesquiterpene,triterpene, flavanone und andere aromatische verbindungen aus Flourensia heterolepis

The investigation of a further Flourensia species afforded in addition to already known compounds 12 new sesquiterpene acids isolated as their methyl esters, a new eudesmane diol, four lupane derivatives and two flavanones, two cinnamic acid derivatives, also isolated as methyl esters and a ketone. The structures are elucidated mainly by spectroscopic methods and by some chemical transformations. Several of the compounds isolated are more or less similar to those isolated from other Flourensia species; the considerable amounts of eudesmanes, however, are unusual. The overall picture of the genus is still relatively uniform. Close relationships to Helianthella are obvious, while to Helianthus, placed in the same subtribe, no clear relations are visible.     

Neue α-santalen- und labdan-derivate aus Ayapana amygdalina

While the roots of Ayapana amygdalina contain typical euparine derivatives, the aerial parts afforded in addition to known compounds two new α-santalene derivatives as well as twelve new labdane derivatives with a partly unusual oxidation pattern, two being norditerpenes. Furthermore, a new bisabolene isomer is present. The structures were elucidated by spectroscopic methods and a few chemical transformations. The chemotaxonomy is discussed briefly.     

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.     

Five diterpenes and other constituents from nine Baccharis species

The investigation of nine Baccharis species afforded, in addition to known compounds, three new clerodane derivatives related to bacchotricuneatin B, two ent-labdane derivatives, two 3-acetoxyflavanones, a benzofuran derivative and a chromene. The overall picture of the chemistry of this large genus is still not very clear.     

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.     

Neue furanoeremophilane und andere sesquiterpene aus vertretern der gattung Euryops

Investigation of a further 27 Euryops species affords, besides known compounds, 55 new furanoeremophilanes together with several other compounds. The configuration of six furanoeremophilanes earlier given as 10β-H has to be changed to 10α-H. Furthermore 9 new eremophilenes were isolated; the configurations of four compounds of this type isolated before have had to be changed. One of the eremophilenes is esterified with 3-methylpent-3(E)-enoic acid, not found before in nature. Two hemiacetals, which are probable precursors of the furanoerephilanes, and a corresponding lactone are also present. Furthermore two benzylic esters, cis-caryophyllene, a bicyclo-germacrene derivative, and a new oplopanone derivative have been found. The structures are elucidated mainly by spectroscopic methods together with some chemical transformations. From the chemotaxonomic viewpoint, the high concentration of very variable furanoeremophilanes may be important. The proposed differentiation into sections however can not be clearly correlated with the chemical constituents, though some taxonomic conclusions seem to be supported by the chemical evidence.     

Neue germacranolide und andere inhaltsstoffe aus vertretern der subtribus gochnatiinae

The investigation of three further species belonging to the subtribe Gochnatiinae, tribe Mutisieae, afforded in addition to known compounds two new eudesmane derivatives and two new germacranolides, closely related to albicolide and salonitenolide. The structures are elucidated by spectroscopic methods and some chemical transformations. The chemotaxonomic aspects are discussed briefly.     

Neue,chlorsubstituierte thiophenacetylenverbindungen mit ungewöhnlicher struktur aus Helichrysum-arten

The investigation of two further Helichryswn species afforded in addition to known constituents three new thiophene compounds with unusual structures. A biogenetic scheme of aromatic ring formation for this new type of chlorine containing compounds is proposed. Most probably, the pyran ring of the chloroenol ether is transformed to an aromatic ring by dehydrogenation, hydrolysis and intramolecular aldol condensation.     

Eudesmane derivatives from Verbesina species

The investigation of seven Verbesina species afforded, in addition to known compounds, several new eudesmane and germacrane derivatives, all bearing a cinnamate or derivatives as residue. Furthermore, a new bisabolene aldehyde and two acetophenone derivatives were isolated. The structures were elucidated mainly by spectroscopic methods and some chemical transformations. The chemotaxonomic situation is discussed briefly.     

Neue labdan-derivate und andere inhaltsstoffe aus Relhania acerosa

The investigation of Relhania acerosa afforded, in addition to known compounds, three new labdane derivatives, two of which are esterified with succinic acid and one which has an anomalous carbon skeleton. Furthermore, several new aromatic compounds are isolated, which are most probably degradated thymol derivatives. The structures are elucidated by spectroscopic methods and by some chemical transformations. The stereochemistry of one of the new labdanes has been established by a partial synthesis. The chemotaxonomic situation is briefly discussed.     

Neue phloroglucin-derivate aus Leontonyx-arten sowie weitere verbindungen aus vertretern der tribus inuleae

The investigation of several South African species of the tribe Inuleae afforded in addition to known compounds 16 new constituents. From Leontonyx a group of 9 new phloroglucinol derivatives, from Stoebe species two new p-hydroxyacetophenone, two thymol and two coumaric acid derivatives and from Relhania a new euparine-derivative were isolated. The structures are elucidated mainly by spectroscopic methods. The chemotaxonomic aspects are discussed briefly. The phloroglucinol derivatives, which in part are derived from geraniol, seem to be especially characteristic.     

Neue acetylenverbindungen aus Leucanthemum-arten und revision der struktur eines germacranolids

The investigation of three Leucanthemum species afforded, in addition to known compounds, two new C₁₇-acetylenes, a new isovalerate, two phenolic acetylenes, a C₁₂-isobutylamide and a new farnesol derivative. Chrysanthemum ferulaceum contains deacetyllaurenobiolide (spiciformin) which is identical with a lactone from Inula britannica previously assumed to be a cis, cis-germacranolide.     

Fourteen heliangolides from Calea species

The investigation of two further Calea species afforded, in addition to known compounds, fourteen new heliangolides, most of them being 11,13-epoxides. One lactone is a new type, a heliangolide substituted with a monoterpene residue. Furthermore, a new chromene and a new dithienyl derivative were isolated. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly.     

Zwei neue sesquiterpenlactone und eine neue sesquiterpensäure aus Helenium puberulum

The reinvestigation of Helenium puberulum afforded in addition to known compounds two new sesquiterpene lactones, desacetyl-isobigelovin and a guaianolide, and an anomalic sesquiterpene hydroxy acid. The structures are elucidated by spectroscopic methods. Chemotaxonomic aspects are discussed briefly.     

Neue furanoeremophilane und weitere inhaltsstoffe aus südafrikanischen Senecio-arten

The investigation of further 27 South African and a few other Senecio species afforded in addition to known compounds 18 new furanoeremophilanes, most of them being cacalol derivatives, two new lactones, a new eudesmane derivative and four acyl pyrrole derivatives. The structures are elucidated by spectroscopic methods mainly. The chemical results on more than 140 species now available indicate much of chemotaxonomic interest. Together with the chemical data on related genera, the taxonomic situation of the subtribe Senecioninae is discussed in connection with the proposed new classification. The chemical data are in good agreement with this new arrangement.