Search

The aerial parts of Mikania alvimii afforded in addition to known compounds seven new ent-labdane derivatives and a 15-nor compound. The struct

The aerial parts of Rutidosis murchisonii afforded several new ent -labdanes, a bisnorditerpene and two α-curcumene derivatives. The structures were elucidated by high field 1 H NMR spectroscopy and a few chemical transformations. The absolute configuration of the diterpenes was established by CD and by the Horeau method. The chemotaxonomic aspects are discussed briefly.

The aerial parts of Ageratina anisochroma gave several thymol derivatives including five new ones, a hydroxypiperitol glucoside, some substituted benzyl benzoates and several germacranolides related to provincialin. From A. ligustrina similar germacranolides, an oplopanone derivative and a further geranyl nerol derivatives were isolated. The structures were elucidated by high field NMR techniques. UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Química

A B S T R A C T Chromosome numbers are presented for 76 species belonging to 35 genera of Compositae from Colombia. Thirty-nine species and three genera, Espeletia (x = 19), Steiractinia (x = 14), and Vasquezia (x = 19), are reported for the first time. New base numbers or chromosome series are recorded in Baccharis (B. nitida, n = 25), Calea (C. caracasana, n = 24), and Liabum (L. megacephalum, n = 10).

The extract of the aerial parts of Ixiolaena leptolepis yielded, in addition to widespread compounds, manool, and four new labdane derivatives, three azulenes and a fitrocurcumene derivative. The structures were elucidated by high field 1H NMR techniques.

Proteopsis argentea (tribe Vernonieae) afforded in addition to known compounds three new sesquiterpene lactones, closely related to those isolated from Eremanthus species, indicating a close relationship between these genera.

The aerial parts of Syncretocarpus sericeus afforded in addition to known compounds a new heliangolide. The chemistry supports the placement of thi

From the new monotypic genus Goyazianthus several kolavenol derivatives were isolated. Their structures were elucidated by spectroscopic methods.

Perymenium featherstonei afforded, in addition to the known ent-kaurene derivative 4α, 15-dihydroencelin, two closely related epimeric acids.

The investigation of Fitchia speciosa afforded, in addition to known compounds, three new sesquiterpene lactones, iso-β-costal, two p -hydroxyacetophenone derivatives and an isoeugenol derivative. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation in this complicated genus is discussed.

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 1 H NMR spectroscopy. The chemotaxonomic situation is discussed briefly.

The polar parts of Campovassouria bupleurifolia afforded in addition to several known sesquiterpene lactones a further β-lactone and a germacranolide acid.

The investigation of AUSTROLIABUM CANDIDUM afforded, in addition to several known sesquiterpene lactones, four new ones, including three germacranolides with an ether bridge, as well as an unusual glucoside. The structures were elucidated by spectroscopic methods.

A reinvestigation of the aerial parts of Heterotheca latifolia afforded four new cadinene derivatives.

The investigation of the aerial parts of Mikania cynanchifolia afforded, in addition to miscandenin, five new sesquiterpene lactones, miscandenin-1,2-epoxide, an isomiscandenin and three further dilactones related to mikanolide. The structures of these new compounds were elucidated by high field 1 H NMR spectroscopy. The biogenetic relationships of the sesquiterpene lactones are briefly discussed.

Piptolepis leptospermoides afforded, in addition to known compounds, a new eremanthanolide and a germacranolide closely related to piptolepolide.

The investigation of one representative of the genus Morithamnus afforded, in addition to several known compounds, a new ent -labdane derivative, a new hydroxy- ent -kauranol and three tremetone derivatives. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly.

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.

The aerial parts of Werneria stuebelii afforded in addition to β-cedrene and bicyclogermacrene eight derivatives of methyl p -coumarate, all being formed by prenylation. The structures were elucidated by their molecular formulae and their 1 H NMR spectra. The chemotaxonomy of the Andean genus Werneria is discussed briefly.

The investigation of three Peruvian Coreopsis species afforded, in addition to compounds isolated previously from this genus, two new tetraynenes and five sesquiterpenes all related to perezone, including a tricyclic ketone with a cedrane skeleton closely related to pipitzol. The structure were elucidated by spectroscopic methods.

The aerial parts of Calotis dentex afforded two known C 10 -acetylenic esters and a new compound, Z -dehydromatricarianol acetate, while those of C. multicaulis gave Centaur X 3 and two new esters, the angelate of E -dehydromatricarianol and the very unusual 5-acetoxy-8 Z -deca-1,8-dien-3,6-diyne. The aerial parts of C. erinacea afforded, in addition to several known acetylenes, three new esters of dehydromatricarianol while the roots gave, in addition to matricariaester and dehydromatricariaester, two unusual C 17 -ketones. The structures were elucidated by spectroscopic methods. The chemotaxonomy is discussed briefly.

The roots of Calea harleyi afforded four germacranolides closely related to chapliatrin and two derivatives of p -hydroxyacetophenone related to the acyloxycalefoliones.

The aerial parts of Austrobrickellia patens afforded five new labdane derivatives. In addition a caryophyllenic acid and several known compounds were isolated.

The aerial parts of Aristeguietia buddleaefolia afforded, in addition to known compounds, three new diterpenes, all being 12, 13-E-abienol derivatives. A further diterpene turned out to be jhanidiol-18- O -acetate, isolated earlier from an Ageratina species. Furthermore two derivatives of hydroxy dihydroconiferyl alcohol are present. The structures were elucidated by spectroscopic methods and by some chemical transformations.

A re-investigation of Chromolaena morii afforded seven further prostaglandin-like fatty acids.

Ageratina ixiocladon afforded several p -hydroxyacetophenone derivatives and diterpenes including six new ent -clerodanes. Two further species, which are also placed in the subgenus Ageratina , gave p -hydroxyacetophenone derivatives which seem to be characteristic for this group. The structure were elucidated by high field 1 H NMR techniques.

A new guaianolide, 11 β,13-dihydroeremanthine, together with a caryophyllene derivative and pentacyclic triterpenes, has been isolated from Lychnophora species.

Examination of Kingianthus paradoxus yielded kingiolide, a new pseudoguaianolide, and 20-hydroxygeranylnerol.

The aerial parts of Acanthospermum australe afforded two new sesquiterpene lactones, an acid and a cis,cis-germacranolide, as well as three diterpene lactones of a new type, most probably formed by intermolecular nucleophilic attack of the carboxyl group of an acid epoxide derived from geranylgeraniol. The structures were proposed on the basis of spectroscopic studies.

In addition to known compounds several highly oxygenated guaianolides and eudesmanolides, derived from 1β-hydroxyarbusculin A, were isolated from the aerial parts of Bishopanthus soliceps , a member of a new genus of the tribe Liabeae.

The reinvestigation of the roots and aerial parts of Ageratina riparia afforded ten new chromenes, their structures being determined by spectral data and chemical transfomrations.

Mikania purpurascens afforded in addition to known compounds a 5,10-epoxygermacranolide, while M. arrojadoi gave only known ent -kaurene derivatives.

A reinvestigation of the aerial parts of Conocliniopsis prasiifolia afforded two furoheliangolides, conoprasiolide-9- O ,5′- O -diacetate and