The Structure and Chemistry of Sesquiterpene Lactones from Polymnia maculata

Sesquiterpene lactone containing Mexican Indian medicinal plants and pure sesquiterpene lactones as potent inhibitors of transcription factor NF‐κB

“…1A) and were active down to an concentration of 25 |xg/ml (data not shown). Since it is known that these three Compositae are rich in sesquiterpene lactones (SL) [14][15][16] it seemed likely that this group of compounds is responsible for the observed inhibitory effects. The lactone ring carrying an exomethylene group forms a reactive Michael-system which is a nucleophilic target, e.g., for cystein [15].…”

Melampolides from Smallanthus macroscyphus

“…0.2 ppm. Lactones 2c and 2d were new 8-hydroxy-9-acylated analogs of 8-acylated-9-hydroxy 2b (longipilin, Seaman and Fischer, 1978) from Melampodium longipilum as again shown by a change in the chemical shifts of H-8 and H-9 (Table 1) with H-8 experiencing the expected upfield shift of ca. 1 ppm and H-9 a downfield shift of 0.8 ppm.…”

“…In his treatment of the genus Polymnia within subtribe Melampodiinae of the Heliantheae Wells (1965) treated P. macroscyphus as a synonym of P. connatus Spreng., a view which was adopted by H. who included only P. connatus in his reestablishment of the genus Smallanthus as S. connatus (Spreng.) H. Robinson (for an addition to the genus see Turner, 1988). However the synonymy has not been recognized by Argentine taxonomists who distinguish between these two species which occur in overlapping areas of southeastern South America (Cabrera, 1978;Zardini, 1991;Grau and Rea, 1997).…”

“…However the synonymy has not been recognized by Argentine taxonomists who distinguish between these two species which occur in overlapping areas of southeastern South America (Cabrera, 1978;Zardini, 1991;Grau and Rea, 1997). Articles have appeared on the chemistry of nine Smallanthus species, frequently under the old Polymnia label (Herz andBhat, 1970, 1973;Bohlmann and Zdero, 1977;Bohlmann et al, 1979;LeVan and Fischer, 1979;Bohlmann et al, 1980;Bohlmann et al, 1980;Bohlmann et al, 1980;Bohlmann et al, 1985;Malcolm and Fischer, 1987;Dominguez et al, 1988;Castro et al, 1989;Kakuta et al, 1992;Inoue et al, 1995). Characteristic constituents are sesquiterpene lactones of the melampolide type, such as 1b and 2a with kauranes being isolated mainly from the roots, but there are no reports on the chemistry of either S. connatus or S. macroscyphus.…”

“…macroscyphus represents a slight departure from previously studied Smallanthus species in that it contains a relatively large proportion of the previously unknown class of 8-hydroxy-9-acylmelampolides but otherwise fits the chemical profile of the genus overall. In a recent study of the molecular phylogenetics of the Espeletia complex of Melampodiinae Rauscher (Rauscher, 2002), having examined 13 out of Wells' (Wells, 1965) and 20 Smallanthus species recognized four lineages or clades, one of which consisted of S. connatus, S. fruticosus and S. siegesbeckius. From a chemical point of view, at least, there seems to be somewhat less of an overlap between S. fruticosus (Bohlmann and Zdero, 1977;Bohlmann et al, 1980) andS.…”