Immunologically active polysaccharides of eupatorium cannabinum and eupatorium perfoliatum

From the alkaline aqueous extract of the herbal part of Eupatorium cannabinum and Eupatorium perfoliatum two homogeneous polysaccharides (PI and PII) have been isolated by ethanol precipitation and fractionation on DEAE Sepharose CL-6B and Sephacryl S-400 columns. The structural elucidation was achieved mainly by permethylation, periodate oxidation, basic degradation, methanolysis and reduction experiments, and ¹³C NMR spectrometry. Both polysaocharides, identified as 4-O-methylglucuronoxylans, differ in their M,s (> 500 000 and 40 000) only. The polysaccharides show a phagocytosis enhancing effect as determined in three immunological test systems (carbon clearance, granulocyte- and chemiluminescence test).     

Further heliangolides and guaianolides from Eupatorium altissimum

The investigation of the aerial parts of Eupatorium altissimum from a collection in West Virginia gave three new guaianolides, six heliangolides and a costunolide all closely related to lactones isolated previously from the tribe Eupatorieae.     

Diterpenes from eupatorium turbinatum

The aerial parts of Eupatorium turbinatum afforded three diterpenes, a known clerodane derivative, an unusual abietane derivative and a friedolabdane, liliolide, β-farnesene and the flavonol pachypodol. The structures were elucidated by highfield NMR spectroscopy. The chemotaxonomy is discussed briefly.     

Dimeric guaianolides and other constituents from Gochnatia species

The roots of Gochnatia polymorpha afforded two new bisabolene derivatives and four dimeric guaianolides, two of them being isolated previously from G. paniculata. The aerial parts gave two further dimeric guaianolides. The aerial parts of G. hypoleuca afforded three new germacran-8,12-olides, a germacranolide acid and four additional dimeric guaianolides, which may be characteristic for this genus, while the presence of oxygenated germacranolides seems to be typical for the whole subtribe.     

Dimeric guaianolides from Artemisia sieversiana

The aerial parts of Artemisia sieversiana afforded in addition to known compounds five new guaianolides and four dimeric guaianolides, three of them closely related to absinthin and one derived from estafiatin as a monomer. The structures were elucidated by extensive NMR studies, which allowed the assignment of the 14 chiral centres. Artemisia frigida afforded several known compounds and one new guaianolide, 8-desoxy-cumambrin B, the most likely precursor of many guaianolides.     

An unusual dimeric guaianolide with antiprotozoal activity and further sesquiterpene lactones from Eupatoriumperfoliatum

The CH₂Cl₂ extract of aerial parts of Eupatorium perfoliatum L. exhibits antiprotozoal activity under in vitro conditions, especially against Plasmodium falciparum (IC₅₀ = 2.7 μg/ml). The search for active compounds yielded seven sesquiterpene lactones: Four structurally similar guaianolides, one dimeric guaianolide, and two germacranolides. The guaianolides differ in the degree of oxidation at C-14, ranging from a hydroxyl group up to a free carboxylic acid. The dimeric guaianolide, structurally closely related to the monomers, displays an unusual type of interguaianolide linkage between C-14 and C-4. Except for the germacranolide euperfolitin, all STLs described here were hitherto unknown. Furthermore, the flavonoid aglycones eupafolin, hispidulin, patuletin, and kaempferol were identified in the extract, which, except for kaempferol, have not been described as constituents of E. perfoliatum before. The dimeric guaianolide was shown to be the most active constituent against Plasmodium falciparum (IC₅₀ = 2.0 μM) and was less cytotoxic against rat skeletal myoblasts (IC₅₀ = 16.2 μM, selectivity index of about 8).     

Dehydrocostuslactone and plant growth activity of derived guaianolides

The stereostructures of two new guaianolides, isodehydrocostuslactone and isozaluzanin C, isolated previously from Saussurea lappa, have been confirmed by their correlation with dehydrocostuslactone. Twenty new derivatives have been synthesized from these guaianolides and these have been tested as plant growth regulators. The conjugated lactones which have an exocyclic methylene group at C-4 conjugated with a C-3 ketone, show distinct enhancement in their root-forming potential, as compared with their 3-deoxy derivatives. Of further significance is the fact that these ketones display maximum activity only at lower concentrations. Other compounds show the expected structure-biological activity relationships displayed in general by guaianolides. However, the presence of an epoxide at the C-3, C-4 position does not affect the biological activity, which is indeed the case when the epoxide group occupies the C-4, C-14 position in guaianolides. The major biological parameter studied was rooting in-stem cuttings of Phaseolus aureus.     

Pseudoguaianolides carabrone derivatives from Loxothysanus sinuatus

The aerial parts of Loxothysanus sinuatus afforded in addition to known compounds nine new pseudoguaianolides, three guaianolides and five carabrone derivatives. The structures were elucidated by spectroscopic methods. The chemotaxonomy is discussed briefly. The configurations of two guaianolides were corrected.     

Further guaianolides and 5-alkylcoumarins from gutenbergia and bothriocline species

From Gutenbergia marginata ten new guaianolides were isolated. Two guaianolides isolated previously from Erlangea inyangana are identical with two further lactones and their structures have been revised. From Bothriocline ripensis ethulia coumarin and two further 5-alkylcoumarin derivatives, one being a chromone, were isolated, while B. longipes and B. eupatorioides gave nine 5-alkylcoumarins and two related compounds. The structures were elucidated by highfield NMR techniques and a few chemical transformations.     

A new guaianolide glucoside from aerial parts of Lactuca aculeata

From aerial parts of Lactuca aculeata one new and ten known sesquiterpene lactone aglycones and glycosides were isolated, including four lactucin-type guaianolides, six costus lactone-type guaianolides and one melampolide-type germacranolide. The structure of the new compound was determined as 11β-hydroxycrepidiaside B by high resolution mass spectrometry and 1D- and 2D-NMR spectroscopy.     

Guaianolides from Acroptilon repens

Two new guaianolides have been isolated from the aerial parts of Acroptilon repens.     

Guaianolides from Liatris squarrosa

The isolation of three new guaianolides related to spicatin from Liatris squarrosa is reported.     

Two guaianolides from calea solidaginea

The isolation and structure elucidation of two new guaianolides, solidaginolides A(1) and B(5), from Calea solidaginea are reported. The structures of the new compounds were established by spectroscopic methods.     

New germacranolides,guaianolides and rearranged Guaianolides from Lasiolaena santosii

The aerial parts of L. santosii afforded three new diterpenes, a phenylpropanol, three eudesmane derivatives, three germacranolides, seventeen guaianolides and four rearranged guaianolides of a, so far, unknown type. Furthermore, several known compounds were isolated. The structures of the new compounds, the separations of which caused difficulties, were elucidated by spectroscopic methods and by some chemical transformations. The chemotaxonomic situation is discussed briefly.     

Guaianolides from Saussurea affinis

Cynaropicrin, 11βH-11,13-dihydrodesacylcynaropicrin, aguerins A and B, isoamberboin and the new guaianolides saussureolide and 11βH-11,13-dihydrodesacylcynaropicrin 8-β-d-glucoside were isolated from Saussurea affinis.     

Four guaianolides and other constituents from three kaunia species*

The investigation of three species of the new genus Kaunia afforded four new guaianolides and four thymol derivatives. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly.     

Neue sesquiterpenlactone und andere inhaltsstoffe aus vertretern der Eupatorium-gruppe

The investigation of twelve further species of the Eupatorium complex affords four new germacrolides and seven guaianolides together with new thymol and p-hydroxyacetophenone derivatives. The structures of these compounds have been elucidated by spectroscopic methods. Chemotaxonomic aspects of these findings are briefly discussed.     

Guaianolides from Calea subcordata

Chemical analysis of Calea subcordata yielded three new guaianolides, 8-epi-isobutyrylrupicolin A, 8-epi-isobutyrylrupicolin B and subcordatolide A, which represent the first guaianolide-type sesquiterpene lactones reported in the genus Calea. The structures of the new compounds were established by chemical and spectroscopic methods.     

Guaianolides and homoditerpenes from Lasiolaena morii

The investigation of Lasiolaena morii afforded in addition to known compounds four new guaianolides, three diterpenes derived from geranyl nerol in