Diterpene carboxylic acids and a heliangolide from Helianthus angustifolius

Two diterpene carboxylic acids, one a new kaurenoid derivative and one the previously characterized labdane, ()-cis-ozic acid, as well as a     

A heliangolide from Chromolaena glaberrima

The investigation of Chromolaena glaberrima afforded, besides the known heliangolide chromolaenide, a new 4-dehydrochromolaenide. The structure of the new compound was elucidated by spectroscopic methods.     

Germacranolides,calbertolides A,B and C,from Calea berteriana

The isolation and structure elucidation of two germacranolides, calbertolides A and B, and a heliangolide, calbertolide C, from Calea berteriana are reported. The structures of the new compounds were established by spectroscopic methods.     

Eudesmanolides,trichomatolides B–E,and A heliangolide from Calea trichomata

Calea trichomata gave in addition to four known 1β-hydroxy-8β-tigloyloxy-11(13)-eudesmen-6α, 12-olide derivatives a new heliangolide, 3-deoxy     

Ent-kauranes and other constituents of three Helianthus species

Aerial parts of Helianthus debilis subsp. cucumerifolius, H. occidentalis and H. simulans afforded a variety of known and some unknown ent-kauranoic acids. H. occidentalis gave, in addition, ciliaric acid and a new biogenetically related atisane derivative occidentalic acid. H. simulans gave the heliangolide leptocarpin and the flavone hymenoxin in addition to ent-kauranes. Several of the diterpenoids from these species inhibited larval growth of the sunflower moth.     

Sesquiterpene lactones,geranylnerol and tremetone derivatives from Ageratina species

The investigation of two further Ageratina species afforded, in addition to known compounds, some new ones, a germacrolide, a heliangolide, a guaianolide, a geranylnerol derivative and a tremetone derivative.     

Further sesquiterpene lactones from Helianthus maximiliani

By using HPLC, a new melampolide, a known heliangolide and three known germacrolides were isolated as minor constituents from a north central Texas population of Helianthus maximiliani. In an earlier report, we identified the germacrolide desacetyleupaserrin as the principal sesquiterpene lactone from this population.     

Caryophyllene derivatives and a heliangolide from Lychnophora species

The investigation of three Lychnophora species afforded three new caryophyllenic acids and a new heliangolide closely related to 15-desoxygoyazensiolide. All three species contain lupeol, lupeyl acetate and eremanthine. The chemotaxonomic situation is discussed briefly.     

Fourteen heliangolides from Calea species

The investigation of two further Calea species afforded, in addition to known compounds, fourteen new heliangolides, most of them being 11,13-epoxides. One lactone is a new type, a heliangolide substituted with a monoterpene residue. Furthermore, a new chromene and a new dithienyl derivative were isolated. The structures were elucidated by spectroscopic methods. The chemotaxonomic situation is discussed briefly.