Neue geranyl-cumarin-derivate und weitere inhaltsstoffe aus der tribus mutisieae

The investigation of further species of the tribe Mutisieae afforded in addition to already known compounds a new sesquiterpene derived from bisabolene, a new chromene, two benzofurans and two geranyl derivatives of typical coumarins. The chemotaxonomic importance of these compounds 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.     

Cis-Kolaveninsäure und weitere inhaltsstoffe aus vertretern der tribus eupatorieae

The investigation of further species of the tribe Eupatorieae afforded in addition to already known compounds two new diterpenic acids, three euparine derivatives, two chromenes and two guaianolides closely related to known structures. The results show again the complexity of the tribe; however, some chemotaxonomic lines are visible.     

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.     

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.     

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 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 sesquiterpene und norditerpene aus vertretern der gattung Libanothamnus

The aerial parts of L. granatesianus afforded in addition to known compounds two nor- ent-kaurenes, while those of L. occultus yielded in addition to several diterpenes, two new dialdehydes derived from silinene. The chemotaxonomic situation is discussed briefly.     

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 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 melampolide und cis,cis-germacranolide aus vertretern der subtribus melampodiinae

The investigation of four South American species of the tribe Heliantheae afforded in addition to known compounds 14 new sesquiterpene lactones, mostly belonging to the melampolides, but four being further examples of cis,cis-germacranolides. The stereochemistry is established by intensive ¹H-NMR studies and some chemical transformations. Some of the new lactones were only obtainable as inseparable mixtures of 2-methylbutyric and isovaleric esters. Furthermore a new acetylenic aldehyde was isolated. The chemotaxonomic situation is discussed especially with regard to the position of the genus Smallanthus.     

Neue germacranolide aus Calea urticifolia

The investigation of Calea urticifolia afforded eight new germacranolides. While five are heliangolides, three are of a new type and have some unusual structural features. The structures are elucidated by extensive ¹H-NMR studies and some chemical transformations. In addition, a new isoeugenol and an unusual phloroglucinol derivative were isolated; the structure of the latter could only be established after some chemical transformations. Other Calea species contain typical C₁₇ acetylenes only, also present in other species of the subtribe Galinsoginae. So far, the results on Calea indicate that the genus is chemically heterogenous.     

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.     

Ein neues clerodan-derivat sowie weitere inhaltsstoffe aus der gattung Macowania ag

The roots of M. corymbosa afford three new benzofuran derivatives very closely related to leysseralangelicate isolated from the related genus Leyssera. The aerial parts of M. glandulosa contain, besides labdanolic acid, a new cis-clerodane derivative, its structure being elucidated by spectroscopic methods and by chemical reactions. The roots of a further Macowania species closely related to M. hamata afford a new ester related to m-thymol.