Sesquiterpenes from three Senecio species

Three succulent Senecio species afforded, in addition to known compounds, two further bisabolene derivatives, a norsesquiterpene and a diol related to β-caryophyllene alcohol, which, however, has a different stereochemistry. Structures were elucidated by spectroscopic methods and some chemical transformations. The chemotaxonomic relevance of the results is discussed briefly.     

Eremophilene and germacrene derivatives from Senecio glanduloso-pilosus

Senecio glanduloso-pilosus afforded in addition to known compounds a new eremophilene deriva- tive and a hydroperoxide derived from germacrene D.     

New furanoeremophilanes from South African Senecio species

An investigation of South African Senecio species afforded in addition to previously known compounds three new furanoeremophilanes, six compounds derived from cacalol and a dihydroeuparin derivative. Structures were elucidated by spectroscopic methods and some chemical transformations. Chemotaxonomical aspects are discussed briefly.     

Two sesquiterpenes from Senecio species

The investigation of further Senecio species gave, in addition to known compounds, two new sesquiterpenes, an eremophilane and a eudesmane derivative.     

Germacrene derivatives and other sesquiterpenes from Senecio species and Lordhowea insularis

From Senecio galpinii six new highly oxygenated germacrene derivatives were isolated, while S. coronatus afforded in addition to known cacalol derivatives two new ones. This species also contained a rare tricyclic sesquiterpene angelate, so far only isolated from one species. From the aerial parts of S. pleistocephalus an angelate derived from cadinene was isolated, while Lordhowea insularis (Benth.) B. Nord. afforded farnesyl angelate, which was reported previously. The structures were elucidicated mainly by high field ¹H NMR spectroscopy.     

Sesquiterpenes from Kleinia species

The investigation of four Kleinia species afforded, in addition to known compounds, seven new germacrane and three oplopane derivatives, all highly oxygenated. This kind of sesquiterpene seems to be characteristic of the genus Kleinia and related succulent species, and its tentative grouping is discussed.     

Trixikingolides and germacrene derivatives from Trixis species

The investigation of two further Trixis species afforded five new sesquiterpenes related to trixikingolide, six new germacrene derivatives and a sesquiterpene derived from rotundene. Some further known compounds were isolated too, which in part may be of chemotaxonomic significance. The structures were elucidated by spectroscopic methods and a few chemical transformations. The relative position of the ester groups in eight of the new sesquiterpenoids however, could not be established with certainty as partial saponifications were not successful.     

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.     

Eremophilane derivatives from Senecio species

The investigation of two further Senecio species afforded two new furanoeremophilanes, four eremophilanolides and a new hydroxyeremophilane. The structures of two furanoeremophilane, isolated before, have been revised.     

New norsesquiterpenes from Senecio digitalifolius

The South African Senecio digitalifolius contain besides several known furanoeremophilanes three new norsesquiterpenes all related to bisabolene. The structures are elucidated by spectroscopic methods.     

New germacranolides from Isocarpha species

The investigation of two Isocarpha species has yielded eight new germacranolides most of them belonging to the heliangolides. In addition to known p-hydroxyacetophenone-derivatives, a new dihydroeuparine derivative was isolated. The chemotaxonomical aspects are discussed.     

Sesquiterpenes and norsesquiterpenes from Pechuel-Loeschea leibnitziae

The aerial parts of Pechuel-Loeschea leibnitziae afforded, in addition to thymohydroquinone dimethyl ether, sitosterol and stigmasterol, xerantholide and its probable precursor, the 11,13-dihydro derivative methyl pechueloate and two norsequiterpenes, probably formed by degradation of the corresponding sesquiterpene acid. Two eudesmane derivatives were also isolated. The chemotaxonomy of Pechuel-Loeschea is discussed briefly.     

Seven furanoeremophilanes from three Senecio species

The investigation of two further Senecio species and the re-investigation of S. inaequidens afforded, in addition to known compounds, seven new furanoeremophilane derivatives. Six of these are closely related to cacalol, a sesquiterpene type which predominates in the species investigated.     

Sandaracopimarene derivatives from Senecio subrubriflorus

Several new sandaracopimarene derivatives were isolated from Senecio subrubriflorus. A triphenyl acetate of shikimic acid and a 4, 7-oxide of bisabolene were also present. The structures were elucidated by high field ¹H NMR spectroscopy. The chemistry of this species differs considerably from that of other Senecio species.     

Sesquiterpenes,guaianolides and diterpenes from Stevia myriadenia

The investigation of Stevia myriadenia afforded in addition to known compounds a new clerodane and a labdane derivative, two guaianolides, a bisabolene and a germacrene derivative. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly.     

Ein neues germacren-derivat sowie ein diterpenmalonat aus Baccharis-arten

The investigation of the aerial part of B. scandens afforded a new ketone, a germacrene derivative. The aerial parts of B. tricuneata var. lineata yielded, in addition to known ent-clerodane derivatives, a malonate of a further diterpene of this type. The structures are elucidated by spectroscopic methods.     

Flavonoids of three local Senecio species

Two isorhamnetin glycosides and two sulphated derivatives are reported for the first time in the genus Senecio.     

Furanoeremophilanes from Senecio smithii

The investigation of Senecio smithii afforded 17 furanoeremophilanes, six of them being isolated for the first time. Furthermore, two new bisabolon