Neue acetylenverbindungen aus chrysothamnus parryl

The investigation of Chrysothamnus parryi afforded, in addition to known compounds, several new matricaria ester derivatives. The structures were elucidated by spectroscopic methods and some chemical transformations. Furthermore, a naphthol derivative was isolated. Chemotaxonomic aspects are 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.     

Weitere acetylenverbindungen aus Centaurea ruthenica

Reinvestigation of the polar fractions of the aerial parts of Centaurea ruthenica afforded, in addition to known compounds, more than 20 new ones, mostly in very small quantities, which in many cases could only partly be separated even after acetylation. The structures, however, could be elucidated by spectroscopic methods. Besides additional C₁₃-acetylenes, several new C₁₄- and C₁₀-acetylenes are present. The compounds isolated are of special interest in view of the proposed biosynthetic scheme of acetylenic compounds of this type.     

Neue sesquiterpene aus Verbesina occidentalis

The investigation of the aerial parts of V. occidentalis affords six new sesquiterpenes their structures being elucidated by spectroscopic methods. All compounds are derived from muurolene. V. enceloides contains simple compounds, only one being new, which is closely related to a diacetate from Amphiachyris amoenum.     

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 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.     

Neue sesquiterpene aus Artemisia koidzumii

The roots of A. koidzumii afforded, in addition to known compounds, a new sesquiterpene with an anomalous carbon skeleton, while the aerial parts yielded a new nerolidol and a new farnesol derivative. The structures were elucidated by spectroscopic methods and some chemical transformations.     

Neue sesquiterpene aus Liabum-arten

The reinvestigation of the roots of Liabum eggersii afforded, in addition to compounds reported before, several sesquiterpene hydrocarbons with unusual carbon skeletons and the first derivative of the propellane modhephene which itself is also present. The roots of L. floribundum contain a tricyclic sesquiterpene with three five-membered rings. This ketone most probably is a derivative of the sesquiterpene silphiperfolene. The structures of the new compounds were elucidated by extensive NMR studies and by some chemical transformations. Two further species only afforded known compounds. The chemotaxonomic situation 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.     

Neue elemanolide und guajanolide aus Zinnia-arten

The investigation of three Zinnia species afforded thirteen new elemanolides. Though these compounds could be separated only in part, the spectroscopic data clearly indicate the proposed structures. Furthermore, four new guaianolides were isolated. The chemotaxonomic situation is discussed briefly.     

Neue kauren-derivate und melampolide aus Smallanthus uvedalia

The investigation of Smallanthus uvedalia afforded, in addition to known compounds, seven new kaurene derivatives and four melampolides. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is 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 labdan-derivate aus Chrysothamnus nauseusus

The South American Chrysothamnus species afforded in addition to known compounds six new labdanetype acids, a bisabolene and a germacrene derivative as well as a new flavanone. The structures were elucidated by spectroscopic methods.