Labdane derivatives from Planaltoa lychnophoroides

The investigation of a representative of the small Brazilian genus Planaltoa afforded, in addition to known compounds, a new toxol derivative and two ent-labdane derivatives, closely related to austrofolin. The structures were elucidated by high field ¹H NMR spectroscopy. The chemotaxonomic situation is discussed briefly.     

A labdane derivative from Chromolaena collina and a p-hydroxyacetophenone derivative. From Stomatanthes corumbensis

A new labdane derivative, 7α-acetoxy-trans-communic acid was isolated from Chromolaena collina. Extraction of Stomatanthes corumbensis yielded a new p-hydroxyacetophenone derivative which was identified as 4-methoxy-3- [3′-methyl-4′-angeloyloxy-but-2-en- 1′-yl ]-acetophenone.     

A further geranylnerol derivative from Helianthopsis species

The investigation of three species of the new genus Helianthopsis gave in all cases furoheliangolides, as well as kaurenic, tricholobanic and beyerenic acids. Furthermore, a new geranylnerol derivative was isolated from H. bishopii. The chemotaxonomy is discussed briefly.     

A caryophyllene derivative from Fleischmannia pycnocephaloides

A new caryophyllene derivative, 15-acetoxy-5,6-dihydro-6,7-dehydrocaryophyllen-5-one, has been isolated from the roots of Fleischmannia pycnocephaloides. Other Fleischmannia sp. yielded previously known compounds.     

6-Hydroxytoxol esters and a seco-dammarane derivative from Abrotanella forsterioides

Abrotanella forsterioides afrorded euparin, 6-hydroxytremetone and three 6-hydroxytoxol esters, one of them not being isolated previously. Furthermore a seco-triterpene was isolated. The tribal position of the genus Abrotanella in the Compositae is still an unsolved problem. Morphological investigations suggest that this genus should be transferred from the tribe Anthemideae to the Senecioneae [1,2]. So far two species have been studied chemically; one atforded ent-kaurane derivatives, while both contained euparin and hydroxytremetone [3].     

2,2-Dimethylchromenes from Eupatorium aschembornianum

Two new chromenes, eupatoriochromene B and C, and a new benzofuran derivative were isolated from the petrol-soluble fractions of the leaves and flowers of Eupatorium aschembornianum.     

Three cadinene derivatives and a prostaglandin-like acid from Chromolaena species

An investigation of the aerial parts of Chromolaena chasleae afforded a prostaglandin-like acid, whose structure followed from the ¹H NMR spectral data and from the reaction with periodate, which afforded a hemiacetal. From a new Chromolaena species, three novel cadinene derivatives were isolated, which were closely related to those isolated previously from this genus.     

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.     

Cadina-4,11-diene from Viguiera oblongifolia

Viguiera oblongifolia afforded two known furanoheliangolides and a new cadinane derivative whose structure was established by spectroscopic methods. From V. lanceolata 17,18-dihydrobudlein A was isolated.     

Kingidiol,a kolavane derivative from Baccharis kingii

The aerial parts of Baccharis kingii afforded quercetin 3,3′-dimethyl ether and a new diterpene closely related to hautriwaic acid. Structure and     

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.     

A kolavane derivative from Liatris scariosa

A new kolavane derivative, 18-acetoxy-kolav-3-en-15-oic acid, has been isolated from Liatris scariosa.