Three new melampolide sesquiterpenes,polymatin A,B and C,from Polymnia maculata Cav. var. maculata

Three new melampolide type sesquiterpene lactones were isolated from Polymnia maculata Cav. var. maculata. Their structures were determined by spectroscopic and chemical means. Based on the presently available chemical data, the chemotaxonomic position of Polymnia within the subtribe is discussed.     

New melampolide sesquiterpene lactones from Melampodium leucanthum

The isolation of five germacranolide sesquiterpene lactones from Melampodium leucanthum Torrey and Gray (Compositae-Heliantheae) is reported. The structures of three new melampolides, melampodin-A acetate, leucanthin-A and leucanthin-B, have been determined by spectral methods and chemical correlations.     

A melampolide and an eudesmanolide from Perymenium mendezii

The aerial parts of Perymenium mendezii var. verbesinioides, afforded two new lactones, the eudosmanolide desacetyl-β-cyclotulipinolide and the melampolide perymeniolide, whose structures were elucidated by chemical and spectroscopic methods.     

A glucoside of urospermal A

The aerial parts of Urospermum picroides afforded, in addition to urospermal A a p-hydroxylphenyl acetate of a glucoside of urospermal A.     

A melampolide from Melampodium heterophyllum

The sesquiterpene lactones melampodin and llβ,13-dihydromelampodin have been isolated from Melampodium heterophyllum.     

Punctatin: A new germacradienolide from Liatris punctata

The isolation and structure determination of punctatin (I), a new germacradienolide from Liatris punctata Hook., is reported. The flavone eupatilin was also found.     

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.     

Six new melampolides from Tetragonotheca helianthoides

Chemical analysis of Tetragonotheca helianthoides L. yielded six new melampolide-type sesquiterpene lactones, tetrahelins A–F. All new compounds have the same medium ring skeleton and differ by the ester moieties at C-8 and C-9. Tetrahelin A and B contain the side chain 2-methyl-2,3-diacetoxybutanoate and tetrahelin E 3-hydroxy-3-methylbutanoate. Both ester side chains have previously not been found in sesquiterpene lactones.     

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.     

A heliangolide from Calea lantanoides

An extract of Calea lantanoides which inhibits larval development of Strongyloides stercoralis and three species of hookworms gave the heliangolide 15-deoxybudlein A.     

A guaianolide from Guevaria sodiroi

A new guaianolide has been isolated from Guevaria sodiroi. It has been assigned the trivial name guevariolide and its structure elucidated.     

Glaucolide from Vernonia staehelinoides

Vernonia staehelinoides afforded a new glaucolide.