Diterpenes from Dictyota dichotoma

Two new and two known diterpenes were isolated from Dictyota dichotoma. The structures of the new diterpenes were elucidated from spectral and X-ra     

Diterpenes and tetranorditerpenes from Acritopappus species

The investigation of four Acritopappus species afforded twenty-three new diterpenes of the labdane or kolavane type and three tetranorditerpenes as well as two new benzofuran derivatives and a hydroxybicyclogermacrene. The structures were elucidated by spectroscopic methods and by some chemical transformations. Though the absolute configuration were not established in all cases, most probably all diterpenes were ent-labdanes or kolavanes (clerodanes). The chemotaxonomic importance of this investigation is discussed briefly.     

Weitere diterpene mit helifulvan-gerüst und andere inhaltsstoffe aus Helichrysum chionosphaerum

The aerial parts of Helichrysum chionosphaerum afforded, in addition to known compounds, a humulene alcohol, an abietane derivative, atisirenic acid and two further representatives of a new class of diterpenes. The structure of the basic acid, named helifulvanic acid, was elucidated by NMR studies and by X-ray analysis. The chemotaxonomic importance of these diterpenes is discussed briefly.     

Flavones and diterpenes of Pamburus missionis (rutaceae)

A new flavone and two diterpenes have been isolated from the extracts of Pamburus missionis. The flavone was identified as an isopentylated apigenin derivative on the basis of spectroscopic studies on it and its diacetate. One of the diterpenes has been identified as daniellic acid and the second as a closely related butenolide.     

Germacranolides and diterpenes from Viguiera species

The investigation of six Viguiera species afforded in addition to known compounds two new diterpenes, the 9,11-dehydro derivatives of trachylobanic and stachenic acid, two new heliangolides closely related to viguiestenin, and the acetate of falcarinol. 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.     

Diterpenes from Stevia monardaefolia

An investigation of Stevia monardaefolia resulted in the isolation of two new labdane type diterpenes, 6α-angeloyloxy nidorellol and 6α-angeloy     

Sesquiterpenlactone und polyine aus der gattung Arctotis

The South African genus Arctotis contains two polyynes sometimes together with diterpenes and sesquiterpene lactones, four of which are new. The structures have been elucidated by spectroscopic methods.     

Millerenolides,sesquiterpene lactones from Milleria quinqueflora

The aerial parts of Milleria quinqueflora afforded 17 new germacranolides (five melampolides and 12 millerenolides), two ent-pimarene and two ent-kaurene derivatives as well as two alicyclic diterpenes and a galactoside. The structures were elucidated by NMR spectroscopy. The chemotaxonomic situation is discussed.     

Diterpenes from Baccharis species

The investigation of ten Baccharis species afforded in addition to known compounds eight new diterpenes, four ent-labdanes, three kaurenes and a clerodane derivative. Furthermore, two new p-hydroxyacetophenones, a flavone, 3′-methoxyxanthomicrol and two matricaria ester derivatives were isolated. The structures were elucidated by spectroscopic methods and a few chemical transformations. The chemotaxonomic situation of the large genus is discussed briefly.     

Beyerene derivatives and other terpenoids from Stevia aristata

The aerial parts of Stevia aristata afforded in addition to known compounds two new germacranolides, a melampolide, a 4Z-melampolide and two beyerene derivatives. From the roots a new dihydrolongipinene derivative was isolated while the aerial parts of Stevia andina gave the E/Z-isomers of austroinulin and 6-desoxyaustroinulin. The absolute configuration of these typical diterpenes is discussed.     

Five labdane derivatives from Koanophyllon conglobatum

A re-investigation of the aerial parts of Koanophyllon conglobatum afforded six new diterpenes, five labdanes and one seco-labdane, as well as two hydroperoxides which may be artefacts.     

Diterpene glycosides and other constituents from argentinian baccharis species

The investigation of the aerial parts of nine Baccharis species from Argentina gave 37 new compounds, seven ent-clerodanes, 13 ent-labdanes, two friedolabdanes, a nor-labdane ketone, seven coumaric acid derivatives, two umbelliferone derivatives, a flavanone, three sesquiterpenes including a nor-furanocadinene and a propiophenone derivative. Ten of the diterpenes were glycosides. The structures and the configurations were determined by highfield NMR spectroscopy and some chemical transformations. The absolute configurations of the diterpenes were proposed following observed Cotton-effects and in one case by using the Horeau-method together with ¹H NMR determination of the configuration of the main phenylbutyrate obtained. The chemotaxonomy is discussed.     

Deltoidin A and B,two new germacrolides from Eupatorium deltoideum

Investigation of E. deltoideum provided two new germacrolide-type sesquiterpene lactones, deltoidin A and B, besides the known guaianolide ligustrin, and diterpenes and triterpenes.     

Phytane and neoclerodane diterpenes from the aerial parts of Inula nervosa Wall.

Three new aliphatic diterpenes (1–3), together with three known neoclerodane-type diterpenes (4–6) were isolated from the aerial parts of Inula nervosa Wall. The structures of 1-3 were elucidated on the basis of 1D and 2D spectroscopic analysis. Additionally, phytane-type and neoclerodane-type diterpenes have not been reported in any species of the genus Inula yet. The phytane-type and neoclerodane-type diterpenes obtained from I. nervosa Wall. suggest this plant maybe have remote genetic relations with other Inula species.     

New diterpenes from Chamaecyparis pisifera

Three new diterpenes, pisiferin, 15-hydroxyferruginol, and O-methyl pisiferic acid have been isolated and the presence of 12-hydroxyabieta-8,11,13-trien-20-al has been confirmed in studies of the leaves of Chamaecyparis pisifera. The structure of pisiferin, a phenolic diterpene with a new carbon skeleton, has been determined by chemical degradation. The presence of diterpenes of the ferruginol type in the leaves of four varieties of C. pisifera has been examined.     

Diterpenoids from Baccharis tola

Erythroxylol-A, oleanolic acid, erythroxylol-A oxide, scopolatine, 4-hydroxy-3-methoxyacetophenone and two new diterpenes, ent-beyer-14-en-18-ol and 19-hydroxy-13-epimanoyl oxide, were isolated from B. tola.     

New germacranolides and other constituents from Trichogoniopsis morii

Trichogoniopsis morii afforded, in addition to known compounds, a new toxol derivative, two diterpenes, a labdane and an ent-kaurane derivative, an eudesmanolide and five germacranolides, a furanoheliangolide and four 1-oxo-germacranolides. The structures were elucidated by spectroscopic methods and a few chemical transformations. The chemotaxonomy of the genus Trichogoniopsis is discussed briefly.     

Terpenoids from the seed of chamaecyparis pisifera: the structures of six diterpenoids

Six new diterpenes, 12-hydroxy-20-nor-abieta-1(10),2,8,11,13-pentaene, pisiferanol (10S,12-dihydroxy-9(10 → 20)-abeo-abieta-8,11,13-triene), pisiferadinol (20S-hydroxypisiferanol), 12-deoxypisiferanol, 1β-hydroxyisopisiferin (1R,12-dihydroxy-9(10 → 2O)abeo-abieta-8,10(20),11,13-tetraene), and the dimethylamine salt of O-methylpisiferic acid were isolated from the seed of Chamaecyparis pisifera. The structures of these diterpenes were established by spectral and chemical methods. In addition, 15 mono-, four sesqui- and nine diterpenes were identified.     

Labdane derivatives from hemizonia species

The investigation of three Hemizonia species afforded in addition to known compounds seven new labdane derivatives, all derived from labd-13-en-15-ol. The absolute configuration of these diterpenes was determined by degradation of the triol by periodate cleavage, which afforded a known norditerpene ketone. From H. fitchii two new chromene esters and the cis-isomer of a known coumarate were isolated. H. congesta afforded in addition to labdane derivatives a hydroxycubebol.