Ineupatorolide-like sesquiterpene lactones from Dittrichia viscosa

Dittrichia viscosa afforded, in addition to known compounds, minute amounts of nine sesquiterpene lactones, all closely related to ineupatorolide B     

Minor sesquiterpene lactones of Helianthus pumilus

The isolation of four known and two new germacradienolides and one known heliangolide from Helianthus pumilus, in addition to the previously report     

Ant-repellent sesquiterpene lactones from Eupatorium quadrangularae

The chloroform extract from the leaves of Eupatorium quadrangularae has been systematically fractionated by following biological activity in a bioassay which measures repellency to the leafcutter ant Atta cephalotes (Formicidae, Attini). Several sesquiterpene lactones were isolated, two of which showed significant ant-repellency.     

Seven sesquiterpene lactones from Ferreyanthus species

The investigation of two Ferreyanthus species afforded seven germacranolides which have not been isolated previously. Two derivatives of linalol were also present. The structures were elucidated by spectroscopic methods. Chemotaxonomic relationships are briefly discussed.     

Glaucolide-like sesquiterpene lactones from Cotula cinerea

The aerial parts of Cotula cinerea gave, in addition to widespread compounds, a characteristic diacetylenic spiroketal enolether and several sesquiterpene lactones, three of them being glaucolide-like lactones. The structures were elucidated by highfield ¹H NMR spectroscopy.     

Two sesquiterpene lactones from Trichogonia gardneri

The structures and stereochemistries of two sesquiterpene lactones from Trichogonia gardneri were established as (6R,7S,8S,9S,IOR)-4E-9,10-dihydroxy-8-tigloxygermacr-4-en-6,12-olide) and (5R*,6R*,7S*,8S*,9R*)-14-acetoxy-3-chloro-9-hydroxy-2-oxo-8-tigloxyguia-1(10),3-dien-6,12-of olide by a combination of NMR spectrometry and X-ray diffraction. The results show that the structures of several sesquiterpene lactones which were isolated previously from related species require revision.     

Two sesquiterpene lactones from artemisia species

Two new sesquiterpene lactones, himeyoshin and montanone, were isolated from Artemisia feddei and A. montana, respectively and identified by chemical and spectral data as1α,2α-epoxy-3-oxo-5,6-dihydroalantolactone and 1,10-dihydro-11,13-dehydromatricarin.     

Two sesquiterpene and three diterpene lactones from Acanthospermum australe

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.     

New types of sesquiterpene lactones and other constituents from Trichogonia species

The investigation of five Trichogonia species afforded seven new furanoheliangolides, three dilactones of a new type, four pairs of epimeric rearra     

New germacrolide- and heliangolide-type sesquiterpene lactones from Melampodium linearilobum

Chemical analysis of Melampodium linearilobum yielded, besides coumarin, seven germacrolide-type sesquiterpene lactones, linearilobin A to G and two heliangolides, linearilobin H and I. All new sesquiterpene lactones are oxygenated at C-14 and C-15 and differ by the number and types of ester moieties at C-8, C-14 and C-15. M. linearilobum represents the first species within the genus known to produce germacrolides and heliangolides instead of the more common melampolides.     

Three bourbonenolides and other sesquiterpene lactones from two vernonia species

A re-investigation of V. arkansana afforded several new sesquiterpene lactones, three bourbonenolides, obviously closely related to those isolated from this plant previously, a glaucolide and a methoxy derivative most probably formed by fragmentation of the corresponding bourbonenolide. From V. profuga in addition to known lactones a new guaianolide was isolated. The biogenetic relationships of the Vernonia sesquiterpene lactones are discussed briefly.     

Pseudoguaianolides and other sesquiterpene lactones from Gaillardia species

The aerial parts of two Gaillardia species afforded in addition to known sesquiterpene lactones 23 new pseudoguaianolides, two dugaldiolide derivatives and two seco-neopulchellin derivatives. The structures were elucidated by spectroscopic methods. Biogenetic relationships are discussed briefly.     

Modified eudesmanolides and other sesquiterpene lactones from Wunderlichia mirabilis and Actinoseris polymorpha

Re-investigation of Wunderlichia mirabilis afforded three new modified eudesmanolides of the same type isolated previously from an Onoseris species, and minute amounts of a germacranolide for which a structure only could be proposed. Actinoseris polymorpha also contained a new germacranolide, the angetate of desacetyllaurenobiolide. Structures were elucidated by spectroscopic methods and by some chemical transformations. The significance of these findings is discussed briefly.     

Further sesquiterpene lactones from Calea and Viguiera species

The aerial parts of Calea clematidea gave three new germacranolides, those of Viguiera procumbens two orizabin derivatives and those of V. linearis dihydrobudlein A. In addition to these lactones, several known ones were isolated.     

Oxepane diterpenoids sesquiterpene lactones from ‘zoapatle’ (montanoa tomentosa), a mexican plant with oxytocic activity

Investigation of the ‘tea’ prepared from the leaves of ‘zoapatle’ (Montanoa tomentosa), resulted in the isolation of the known biologically active oxepane diterpenoids zoapatanol and montanol, the known sesquiterpene lactones zoapatanolide A, C and D as well as two new biologically active oxepane diterpenoids and a new sesquiterpene lactone. The structures of the new compounds were established by spectroscopic methods.     

New germacranolides and other sesquiterpene lactones from Dicoma species

Two subspecies of Dicoma anomala afforded, in addition to known compounds, an eudesmanolide, a guaianolide and four germacranolides, the latter being closely related 8, 12-lactones. D. schinzii gave three new germacranolides and D. zeyheri a pair of isomeric acetylenic compounds. The structures were elucidated by highfield ¹H NMR spectroscopy. The chemotaxonomic situation of this genus is discussed briefly.     

New sesquiterpene lactones from Artemisia herba alba

The structures of herbolides A, B and C, new sesquiterpene lactones isolated from Artermisia herba alba, were determined by chemical and spectroscopic methods.     

Sesquiterpene lactones from Ambrosia maritima (Damssissa)

Six sesquiterpene lactones were isolated from the aerial parts of Ambrosia maritima. Four pseudoguaianolides were isolated for the first time in addition to parthenin and neoambrosin.     

Two sesquiterpene lactones of Calea ternifolia var. Calyculata

Chemical analysis of Calea ternifolia var. calyculata yielded the known sesquiterpene lactone calein A, as well as two new modified heliangolid