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.     

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     

A new melampolide from Sigesbeckia orientalis

Isolation and structure determination of orientalide, a new melampolide closely related to the acanthospermals, from Sigesbeckia orientalis is reported.     

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.     

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.     

A carotane derivative and a eudesmanolide from Inula crithmoides*

The aerial parts of Inula crithmoides afforded a new carotane derivative and a eudesmanolide, inucrithmolide. The most probable structures were elucidated by the spectroscopic data and by some chemical transformations.     

A melampolide from Melampodium heterophyllum

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

New germacranolides from Inula heterolepis

The aerial parts of Inula heterolepis afforded two new germacranolides and a new eudesmanolide, all closely related to haageanolide, which was also isolated.     

11,13-Dehydroeriolin,schkuhrioidin and schkuhriolid,germacranolides from Schkuhria species

The isolation is reported of the new germacrolide, 11,13-dehydroeriolin, the new melampolide schkuhrioidin and schkuhriolide from Schkuhria schkuhrioides. 11,13-Dehydroeriolin is also a constituent of S. virgata. The structure and stereochemistry of the new compounds were established on chemical and spectroscopic grounds.     

Heliangolides from Helianthus maximiliani

The isolation is reported of tifruticin, acetyltifruticin, deoxytifruticin, acetyldeoxytifruticin, an orizabin analog and three heliangolides from Helianthus maximiliani.     

Terpenoids and a flavan-3-ol from viguiera quinqueradiata

The isolation is reported of the new natural products from Viguiera quinqueradiata, acetylleptocarpin and (2R,3S-4′-hydroxy-3′,5,7-tri-O-methyl-flavan-3-ol. The diterpenes 15α-angeloyloxy-ent-kaur-16-en-19-oic acid, 15α-tigloyloxy-ent-kaur-16-en-19-oic acid and the sesquiterpene lactones leptocarpin and budlein A were also found.     

An isomer of xanthanol from Xanthium orientale

The aerial parts of Xanthium orientale afforded an isomer of xanthanol.     

Elemanolides from Zinnia peruviana

Zinnia peruviana from Honduras afforded two new acetal-type elemanolides as well as a mixture consisting primarily of zinaflorin III.     

Tetraludins D to N,eleven new melampolides from Tetragonotheca ludoviciana

Eleven new melampolides, tetraludins D-N, were isolated from aerial parts of Tetragonotheca ludoviciana. Tetraludins D and E, F and G, J and K, and L and M represented epimeric pairs which differed only at one chiral centre of the five-carbon ester side chain at C-8. In benzene-d₆, the ¹H NMR spectra of the diastereomeric pairs of melampolides exhibited well-separated signals in particular for the absorptions due to the ester side chains that differed in chirality.     

Germacranolides from Melampodium americanum and Melampodium pilosum

Chemical analysis of Melampodium americanum yielded, besides the known melampodinin A, four new melampolides, melampodinin B, melampodinin C, 9-des     

Ent-kauranes and 10α-methyl-eudesman-8αh,12-olides from wedelia calycina and wedelia hispida

The aerial parts of Wedelia hispida furnished small amounts of three new 10α-methyl-eudesman-8α,12-olides as well as some known ent-kauranes. Wedelia calycina yielded various ent-kaurane derivatives, several of them new.