Longipinanes and a germacranolide carboxylic acid from Stevia potrerensis

The herb Stevia potrerensis afforded five longipinene derivatives, three of them new, and a new germacranolide carboxylic acid.     

Annuithrin,a new biologically active germacranolide from Helianthus annuus

Investigations on growth inhibition in Helianthus annuus led to the isolation of a new sesquiterpene lactone, a germacranolide with an α-methylene-γ-lactone moiety. The structure of this new germacranolide, annuithrin, was elucidated by spectroscopic methods. Its biological activity has been proven by growth inhibition in straight growth tests, antibacterial tests and inhibition of DNA-/RNA-synthesis in cells of the ascitic form of Ehrlich carcinoma.     

A germacranolide and a longipinene derivative from Eupatoriadelphus purpureus

The roots of Eupatoriadelphus purpureus contain tridecapentaynene, β-pinene and five p-hydroxyaecetophenone derivatives. By contrast, the aerial parts have germacrene D, lupeol and its isomers, coumarin, a new sesquiterpene tiglate and a new germacranolide.     

Four guaianolides,a eudesmanolide and a germacranolide from Ursinia saxatilis

An investigation of Ursinia saxatilis afforded in addition to known compounds a new eudesmanolide derived from ursialpinolide, a germacranolide rel     

Germacranolides from Piptolepis Ericoides and Vanillosmopsis species

The aerial parts of Piptolepis ericoides afforded in addition to known compounds two new germacranolides, a zexbrevanolide and piptolepolide, tentatively characterized as a germacranolide with a trans-disubstituted double bond. From the aerial parts of two Vanillosmopis species in addition to goyazensolide, a new isomer with an exocyclic double bond was isolated.     

Viguilenin,a germacranolide from Viguiera linearis

The new germacranolide, viguilenin, was isolated from Viguiera linearis and its structure was established by chemical and spectroscopic means.     

Maculatin: An isomer of uvedalin epoxide from Polymnia maculata

The isolation of a new germacranolide, maculatin IIc or IId, from Polymnia maculata Cav. is reported.     

Germacranolides from Piptolepis leptospermoides

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

A new sesquiterpene lactone from Elephantopus scaber

A methanolic extract of the plant Elephantopus scaber was found to contain lupeol, stigmasterol and a new germacranolide dilactone 11,13-dihydrodeoxyelephantopin.     

15-Acetoxycostunolide from Magnolia sieboldii

A new germacranolide isolated from M. sieboldii was shown to be 15-acetoxycostunolide by spectroscopic and chemical methods. ¹H NMR spin decoupling and NOE experiments in the presence of a lanthanide shift reagent were used for structure elucidation.     

Some sesqui- and diterpenes from the tribe eupatorieae

The aerial parts of Trichogonia salviaefolia afforded a new ent-kaurenic acid derivative and a germacranolide which, most likely, is the precursor of the trichosalviolides. The aerial parts of Liatris spicata gave 1α-hydroxybacchotricuneatin A and a guaianolide, which may be the precursor of spicatin. From Brickellia vernicosa some further dehydronerolidol derivatives were isolated.     

Three sesquiterpene lactones from Helianthus niveus subsp. canescens and H. argophyllus

Further investigation of the minor terpenoids in Helianthus niveus subsp. canescens and H. argophyllus afforded two known 12,8-fused sesquiterpene lactones, 3-acetylchamissonin and simsiolide as well as one new germacranolide, argophyllin C. Identification and structure elucidation of these lactones by ¹H NMR and chemical transformations are described.     

Three furanoheliangolides from Calea villosa

Calea villosa afforded three new sesquiterpene lactones, two furanoheliangolides and an epoxy- germacranolide, as well as several known compounds. The structures were elucidated by spectroscopic methods.     

Mariolin,a germacranolide from Anacyclus radiatus

A new sesquiterpene lactone, the germacranolide mariolin, was isolated from the aerial part of Anacyclus radiatus along with several known compounds. The structure of mariolin was determined by spectroscopic methods.     

Novanin: A germacranolide from Artemisia nova

A new germacranolide, novanin (I), has been isolated from Artemisia nova and its structure determined. The compound is also present in small amount in A. tripartite Rydb. ssp. rupicola Beetle.     

Marginatin,a new germacranolide from Vernonia species

A new germacranolide, marginatin, has been isolated from three species of Vernonia from the central United States, V. marginata, V. fasciculata and V. arkansana, and its structure has been determined.     

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.     

Three biologically active heliangolides from Helianthus annuus

Growth inhibiting substances in Helianthus annuus have been investigated. From the ethanolic extract a new germacranolide with an α-methylene-γ-lactone moiety, the heliangolide niveusin B and its ethoxy derivative were isolated and their structures elucidated by spectroscopic methods. The biological activity of each was determined by inhibition in Avena coleoptile tests and antimicrobial tests.     

Sesquiterpene lactones from Brachylaena species

The investigation of two Brachylaena species afforded in addition to known sesquiterpene lactones and other constituents five new lactones, a germacranolide, a guaianolide and three eudesmanolides. The structures were elucidated by spectroscopic methods. The chemotaxonomy of this complex genus is discussed.     

Neue sesquiterpenlactone und nerolidol-derivate aus Ursinia-arten

The aerial parts of U. anethoides afforded, in addition to new nerolidol derivatives, a new germacranolide. The structure could only be elucidated by formation of the corresponding pyrazoline derivative and by comparison of the ¹H NMR data with those of similar pyrazolines. The aerial parts of U. alpina also contain a new nerolidol derivative and, in addition to the known 9β-hydroxycostunolide, a new eudesmanolide. The roots of all species contain furanosesquiterpenes, which are also present in related genera.