Sesquiterpene lactones from Schkuhria anthemoidea var. wislizenii

Elemanolide sesquiterpenes and eudesmane sesquiterpene glycosides from Centaurea hierapolitana

“…The 13 C NMR spectrum of 1 showed 19 signals. After subtraction of the four carbon resonances of the methacrylate units, the remaining 15 signals were attributable to a 1,3,11(13)-elematrien-12,6-olide sesquiterpene framework based on detailed examination of the 1 H and 13 C NMR spectra and previously reported spectroscopic data of related metabolites (Stewart and Mabry, 1985;Rustaiyan and Ganji, 1987;Cuenca et al, 1993;Karioti et al, 2002). The covalent connectivities of the elema-trien aglycon of 1 were established by analysis of the DQF-COSY, and HMQC spectra, which revealed the aforementioned skeleton (Fig.…”

New Melampolides from Schkuhria schkuhrioides

“…Species belonging to the genus Schkuhria are known sources of sesquiterpene lactones, − diterpenes, polyacetylenes, and other constituents. , Some species and their varieties are used in traditional medicine, , and different biological activities have been reported for some constituents. , Previous papers have reported a series of melampolides, , elemanolides, , and flavonoids from the aerial parts of S. schkuhrioides (Link & Otto) Thellung (Compositae). We have now characterized additional sesquiterpene lactones from this source, and the antimicrobial and cytotoxic activities of some melampolides were evaluated.…”

Sesquiterpene Lactones, Acyl Phenyl Propanoids and Other Constituents from Schkuhria pinnata var. wislizeni. Antioxidant Evaluation

“…Acetylation of the natural prod- The 1 H NMR data of 5 (see experimental) and 7 [29] were practically identical to those previously published for an acetyl elemanolide (8) and its desacetyl analogous (9) isolated from the species identified as S. anthemoidea var. wislizeni [24], indicating that these should be the same substances. However, the reported structures of elemanolides with a trans fused lactone closed at C-6 and an α-oriented hydroxyl at C(8) were not consistent with the spectroscopic analysis, particularly with the Samek's rule [25] and with the observed NOESY correlations (fig.…”

“…Spectroscopic discussion of 5 and its diacetyl derivative 6 allowed the structural correction of the sesquiterpene lactones 8 and 9 previously isolated from S. anthemoidea var. wislizeni [24]. Compounds 2, 10 and 11 are new.…”