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 labdan- und pimaren-derivate aus Palafoxia rosea

The investigation ofPalafoxia rosea afforded in addition to known compounds five new labdane derivatives and five pimarene derivatives. The structures are elucidated by spectroscopic methods and some chemical transformations. The chemotaxonomic situation of the genus is discussed briefly.     

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 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 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 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.     

Neuartige cumarin-derivative aus Ethulia conyzoides

The aereal parts of Ethulia conyzoides contain two new coumarins which are related to those of Erlangea and Bothriocline. They are, however, condensed with a terpene. The structures have been elucidated by spectroscopic methods.     

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 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.     

Coumarins from Pterocaulon balansae and P. lanatum

Analysis of the petrol-diethyl ether extracts of Pterocaulon balansae and P. lanatum aerial parts afforded, besides puberulin, scopoletin-[2′     

New sesquiterpenes from Senecio oxyodontus

The South African plant, Senecio oxyodontus, contained in addition to known compounds several new sesquiterpenes, which were all of the bisabolene type. The structures were elucidated by spectroscopic methods and some chemical transformations. The constituents were closely related to those from one other South African Senecio species and in contrast to most Senecio species which contain very different structural types, mainly of the furanoeremophilanes type.     

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 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.     

Labdane derivatives and flavones from Gutierrezia dracunculoides

An investigation of the aerial parts of Gutierrezia dracunculoides afforded, in addition to known compounds, three new labdane derivatives, all related to lambertianic acid, 17-hydroxy- and 17-acetoxylambertianic acid and 7α- hydroxylambertianic acid, two esterified and three highly oxygenated flavones, 5,7,4′-trihydroxy-3,3′-dimethoxy- flavone-4′-O- [2-methylbutyrate] and isovalerate, 3′,5′-dihydroxy-3,5,6,7,8,4′-hexamethoxyflavone, 5,3′,5′-trihydroxy- 3,6,7,8,4′-pentamethoxyflavone and 5,7,3′,5′-tetrahydroxy-3,6,8,4′-tetramethoxyflavone. The structures were elucidated by spectroscopic methods and a few chemical transformations.     

New sesquiterpenoids of Bombax malabaricum

Hemigossypol-6-methyl ether, reported to be present in the root bark of Bombax malabaricum, has been shown to be isohemigossypol-1-methyl ether. Isohemigossypol-1,2-dimethyl ether, 8-formyl-7-hydroxy-5-isopropyl-2-methoxy-3-methyl-1,4-naphthaquinone, 7-hydroxycadalene and an unidentified phenolic compound have also been isolated. Long range couplings in the ¹H NMR spectrum of isohemigossypol-1-methyl ether have been established by decoupling experiments.     

Neue sesquiterpenlactone und nerolidol-derivate aus Ursinia-arten

The aerial parts of U. anethoides afforded, in addition to new nerolidol derivatives, a new germacranolide. The structure could only be elucidated by formation of the corresponding pyrazoline derivative and by comparison of the ¹H NMR data with those of similar pyrazolines. The aerial parts of U. alpina also contain a new nerolidol derivative and, in addition to the known 9β-hydroxycostunolide, a new eudesmanolide. The roots of all species contain furanosesquiterpenes, which are also present in related genera.     

Neue sesqui- und diterpene aus Bedfordia salicina

An Australian member of the tribe Senecioneae, Bedfordia salicina, contains besides known compounds new dimeric eremophilenolides, new kolevane derivatives, a kaurenic acid and several further sesquiterpenes, most of them related to xanthatine. The structures are elucidated mainly by spectroscopic methods and by some chemical transformations. The chemotaxonomic aspects of these findings are discussed briefly.     

Neue diterpene aus Gnaphalium-arten

The investigation of Gnaphalium undulatum afforded two new labdane derivatives, one having a new carbon skeleton, and a new flavonol. Furthermore, an unknown diterpene lactose is present; its structure, however, could not be elucidated. The only American species investigated contains the trans-isomer of the precursor of the acetylenic chloroenol ether, which is widespread in Gnaphalium and in related genera. 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.     

Neue germacren-derivate aus Senecio-arten

From the succulent Senecio species, S. cylindricus, eight new germacrene derivatives were isolated, while S. erosus afforded two new furanoeremophilones. Six further species only contain known compounds. The chemotaxonomic importance of these findings are briefly discussed.