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.     

Ent-norlabdane triols from Austroeupatorium inulaefolium

Two new ent-norlabdane triols were isolated from the above-ground parts of Austroeupatorium inulaefolium.     

Ent-labdane derivatives from gutierrezia grandis

Two new diterpenes, 3α-angeloyloxy-18-hydroxy-13-furyl-ent-labda-8(17)-ene and 3α-hydroxy-18-angeloyloxy- 13-furyl-ent-labda-8(17)-ene and an only recently reported third diterpene, 3α, 18-dihydroxy-13-furyl-ent-labda-8(17)-ene, were isolated from the leaves of Gutierrezia grandis. Their structures were determined by mass spectral, IR, ¹H NMR and ¹³C NMR data was well as chemical evidence.     

Ent-pimaranes, ent-kauranes,Heliangolides and other Constituents of three Helianthus species

Aerial parts of Helianthus strumosus gave the C-2′ epimer of the heliangolide 2′,3′-dihydrobudlein A as well as the flavones nevadensin, hyme     

Neo-clerodane diterpenoids from Baccharis incarum

A new neo-clerodane diterpenoid was isolated from the aerial parts of Baccharis incarum together with the previously known diterpenoids bacchalineol and barticulidiol.     

Gutierrezial and further diterpenes from Gutierrezia sarothrae

The aerial parts of Gutierrezia sarothrae afforded in addition to polyalthic acid, daniellic acid and nivenolide, 14 new diterpenes, most of them closely related to polyalthic acid. One of these compounds has a new carbon skeleton. The structures were elucidated by spectroscopic methods and by some chemical transformations.     

Diterpenes from Heteropappus altaicus

The aerial parts of Heteropappus altaicus afforded, in addition to more widespread compounds and known clerodane derivatives, three new ones and a seco-clerodane acid. Furthermore, a neryl geraniol derivative was present. The structures were elucidated by spectroscopic methods. The stereochemistry was solved by NOE difference spectroscopy and by the Horeau method.     

Clerodane and labdane diterpenoids from Baccharis species

The investigation of eight Baccharis species afforded, in addition to known compounds, five new clerodanes, three labdane derivatives and a nor-diterpene as well as one hydroperoxide derived from 4α-hydroxygermacra-1(10), 5-diene. The structures were elucidated by spectroscopic methods. The structures of esters isolated previously from B. cassinaefolia have to be revised. Chemotaxonomic aspects are discussed briefly.     

Ent-kauranes and trachylobanes from Helianthus radula

The aerial parts of Helianthus radula afforded a variety of known ent-kauranoic acids as well as two new substances, 11-oxotrachyloban-19-oic a     

Ent-kauranes and other constituents of three Helianthus species

Aerial parts of Helianthus debilis subsp. cucumerifolius, H. occidentalis and H. simulans afforded a variety of known and some unknown ent-kauranoic acids. H. occidentalis gave, in addition, ciliaric acid and a new biogenetically related atisane derivative occidentalic acid. H. simulans gave the heliangolide leptocarpin and the flavone hymenoxin in addition to ent-kauranes. Several of the diterpenoids from these species inhibited larval growth of the sunflower moth.     

Sesquiterpene lactones and diterpenes from Mikania periplocifolia

The aerial parts of two collections of Mikania periplocifolia gave, in addition to mikanolide, miscandenin and several other known sesquiterpene dilactones related to them, the new dilactones 3β-hydroxy-11βH,13-dihydroisabelin, 11βH,13-dihydrodeoxymikanolide and mikaperiplocolide and three new geranylnerol derivatives.     

Homogeranyl nerol derivatives and a melampolide from Smallanthus glabratus

The investigation of the aerial parts of Smallanthus glabratus from two locations afforded the same known compounds but some additional new compounds which were not present in both collections. From the first location typical melampolides, one of them not isolated previously, and two homoditerpenes were isolated. The material from the second location gave four closely related homoditerpenes and two geranyl nerol derivatives from which the homoditerpenes were derived. The structures were elucidated by high field ¹H NMR spectroscopy. Chemotaxonomic aspects are discussed briefly.     

Ent-labdanes from Mikania alvimii

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

Viscidic acid A and B,two ent-labdane derivatives from Chrysothamnus viscidiflorus

The chemical investigation of Chrysothamnus viscidiflorus afforded, in addition to known bisabolene derivatives, elemicin and p-hydroxyacetophenone, two new diterpene acids. Their structures were determined, by spectroscopic methods and some chemical transformations, as ent-labd-8(17),13E-dien-15-ol-18-oic acid (viscidic acid A) and ent-labd-8(17),13E-dien-15-acetoxy-18-oic acid (visidic acid B).     

Ent-labdane-type diterpene glucosides from leaves of Rubus chingii

Previously, a sweet steviol bisglucoside named rubusoside was isolated from leaves of a Chinese Rubus spp. which was tentatively assigned as R. chingii. From leaves of Japanese Rubus chingii (Japanese name Gosho-Ichigo) which are not sweet, five ent-labdane-type diterpene glucosides named goshonosidies F1-5 were isolated instead of rubusoside and their structures were elucidated. The name ‘R. suavissimus’ has been proposed for the Chinese plant.     

Diterpenes and sesquiterpene lactones from Mikania congesta

The chloroform extract of the aerial parts of Mikania congesta, afforded four new geranylnerol derivatives, new analogs of deoxyelephantopin, a new melampolide and several known compounds. Structures were elucidated by spectroscopic methods and chemical transformations.     

Diterpenes from the roots of Salvia canariensis

The new diterpenes, deoxocarnosol 12-methyl ether, salvicanol and 6α-hydroxydemethylcryptojaponol, and the known ones, sugiol and demethylcryptojaponol, have been isolated from the bark of the roots of Salvia canariensis.     

Polyacetylenes from Chrysanthemum leucanthemum

Fifteen acetylenic compounds have been isolated and characterized from the flower heads of Chrysanthemum leucanthemum L. Five of these acetylenes have not previously been published as naturally occurring compounds. These are: 1,7(c)-hexadecadien-10,12,14-triyne; 1,8(c)-heptadecadien-11,13,15-triyne; 4(c)-tridecen-7,9,11-triyn-l-ol; 1,8(t)-hexadecadien-10,12,14-triyn-(6·7)-oxirane; and [3(t),5(t)-tridecadien-7,9,11-triyn-l-yl]-3-methyl-2-butenoate. The first three compounds are interesting since they are important intermediates in previously postulated biogenetic pathways. Ten acetylenes have been identified from the roots of the same plant, all of these having different structures from those of the flower heads. One of the acetylenes, [3(t), 5(t)-tridecadien-7,9,11-triyn-l-yl]-3-methylbutyrate, from the roots has never been reported as a naturally occurring compound.