Neue pyron-derivate aus Helichrysum-arten

The investigation of five further Helichrysum species afforded in addition to known compounds nine α-pyrone derivatives all also being phloroglucinol derivatives. Furthermore, a new toxol derivative has been isolated. The structures were elucidated by extensive NMR studies and by some chemical transformations. The chemotaxonomic situation is discussed briefly.     

Neue ent-labdan-derivate aus Austroeupatorium chaparense

The aerial parts of A. chaparense afforded, in addition to known compounds, five new ent-labdane derivatives, while Campovassouria bupleurifolia contains mainly kaurene derivatives. The chemotaxonomic situation is briefly discussed.     

Neue flavone und phloroglucin-derivate aus Helichrysum herbaceum und Helichrysum chrysargyrum

The investigation of two further South African Helichrysum species afforded five new flavones and six new phloroglucinol derivatives. The structures were elucidated by spectroscopic methods and some chemical transformations. The chemotaxonomic situation is discussed briefly.     

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.     

Chromones and flavans from Marshallia obovata

An investigation of Marshallia obovata afforded, in addition to known thymol derivatives, one new ester. Furthermore six new chromone derivatives, all prenylated, were present together with the known spathelia chromene. The main constituent was a flavan already isolated from M. grandiflora but five new flavans were also isolated. Besides other widespread compounds a tetraester of inositol was isolated in minute amounts. All the structures were elucidated by spectroscopic methods or chemical transformations. Surprisingly, even the main 4-methoxyflavan could be split by periodic acid.     

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.     

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 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 ent-atisiren- und ent-kaurensäure-derivate aus Helianthus-arten

The investigation of four Helianthus species afforded, in addition to known compounds, four new atisirenic acid derivatives, a new ent-kaurenic acid derivative, three new labdane derivatives and an unknown C₁₅-acetylenic compound. The structures of the diterpenes were elucidated by intensive NMR studies and some chemical transformations. An unusual fragmentation in the mass spectra of the atisirenes is discussed briefly.     

Neue phloroglucin-derivate aus Helichrysum natalitium und Helichrysum bellum

Helichrysum natalitium afforded four new phloroglucinol derivatives, while from H. bellum two further compounds of this type have been isolated; H. platypterum yielded two known derivatives. The new structures were elucidated by spectroscopic methods and some chemical transformations. The chemotaxonomical situation is briefly discussed.     

Neue diterpene und acetylenverbindungen aus Nidorella-arten

The investigation of four species of the South African genus Nidorella afforded three new clerodane derivatives, nidorellalactone, isonidorella     

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 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 diterpene und neue dihydrochalkon-derivate sowie weitere inhaltsstoffe aus Helichrysum-arten

The investigation of 25 further Helichrysum species afforded in addition to known compounds a new diterpene, an oxo-geranyllinalol, a second one, most probably a cembrene derivative, and three dihydrochalkone derivatives. The distribution of the constituents in South African Helichrysum species is discussed briefly.     

Labdane and dehydronerolidol derivatives from Brickellia diffusa

An investigation of Brickellia diffusa afforded three new dehydronerolidol derivatives and five new labdane derivatives, all highly oxygenated. The structures were elucidated by spectroscopic methods and a few chemical transformations. The compounds isolated showed close relationships to those isolated from Brickellia sp.     

8-Oxo-α-selinen und neue scopoletin-derivate aus Conyza-arten

The investigation of three South African and a North American Conyza species afforded, in addition to known compounds, a new eudesmane ketone and five new scopoletin derivatives. The structures are elucidated by spectroscopic methods and by some chemical transformations. Two of the scopoletin enol ethers have very unusual structures. While most of the Conyza species investigated so far contain typical C₁₀-acetylenes, also present in related genera, there are some with different chemistry. The relationship of the genus to Aster and Erigeron, however, is clearly indicated.     

Types of sesquiterpenes from Artemisia douglasiana

Artemisia douglasiana afforded, in addition to known compounds, two new C₁₄-acetylenes, five longipinene derivatives, three nerolidol derivatives, a lactone and a ketone with a new carbon skeleton and lavendulol-2-methylbutyrate. The structures were elucidated by spectroscopic methods and some chemical transformations. The configurations of several oxo longipinene-7, 9-di- and 7, 8, 9-triesters isolated previously were corrected. The biogenesis of the new lactones is discussed briefly.     

Neue sesquiterpenlactone und andere inhaltsstoffe aus vertretern der Eupatorium-gruppe

The investigation of twelve further species of the Eupatorium complex affords four new germacrolides and seven guaianolides together with new thymol and p-hydroxyacetophenone derivatives. The structures of these compounds have been elucidated by spectroscopic methods. Chemotaxonomic aspects of these findings are briefly discussed.     

Cuauthemone sesquiterpenoids from Blumea alata

The investigation of five Blumea species afforded, in addition to known compounds, several cuauthemone derivatives, most of them being 7,11-epoxides, some thymol derivatives, an eremophilane epoxide and a himachalane diol. From Pterocaulon virgatum a further himachalane derivative was isolated. The structures were elucidated by spectroscopic methods and in part by partial synthesis.     

Neue labdan-derivate aus Carterothamnus anomalochaeta

The investigation of a Carterothamnus species afforded in addition to known euparine derivatives four new diterpenes, all being labdane derivatives. The structures are elucidated by ¹H-NMR-studies and by some chemical transformations. The chemotaxonomic situation is briefly discussed. The constituents of the Carterothamnus species show a distinct differentiation to those of the neighbouring groups; however, in addition they also indicate some relationships.