The widespread occurrence of functionalized cycloheptane and ring-fused cycloheptane ring systems in numerous classes of natural products has made them the synthetic targets of many investigators. 2 Despite recent advances in hydroasulene syntheses, 3 there are almost no general and direct approaches to ring-fused cycloheptadienes which would also allow for incorporation of numerous labile func...

Knowing the conformational properties of 1(10),4-cyclodecadiene gamma-lactones is important because of the biogenetic and evolutionary implications on the different groups of sesquiterpene lactones. Despite their importance, there are no physicochemical data on the conformational dynamic and the potential energy surface associated with the conformational changes of the cyclodecadiene ring. Fisc...

Biorefinery applications are receiving growing interest due to climatic and waste disposal issues and lack of petroleum resources. Jerusalem artichoke (Helianthus tuberosus L.) is suitable for biorefinery applications due to high biomass production and limited cultivation requirements. This paper focuses on the potential of Jerusalem artichoke as a biorefinery crop and the most viable products ...

Chemical investigation of the Bulgarian species Tanacetum. parthenium, T. millefolium, T. achilleifolium, T. corymbosum and T. macrophyllum afforded in addition to 24 known sesquiterpene lactones a new 12, 8-eudesmanolide 22. Besides, four known highly oxigenated terpenoids and a new keto-diol 30 of the rare iphionane skeleton were also isolated. The structures were elucidated on the basis of t...

In the search for new sources of sesquiterpene lactones, six Centaurea species have been analyzed. The activity against the fungus Cunninghamella echinulata of (+)-cnicin (1) and (+)-salonitenolide (2), isolated from the Centaurea plants, as well as that of (+)-costunolide (3), (-)-dehydrocostuslactone (4), (-)-lychnopholide (5) and (-)-eremantholide C (6), has been evaluated. Compounds 3 and 4...

Structures of three new sesquiterpene lactones 1-3, isolated from the pericarps of Illicium merrillianum, have been assigned as 14-O-benzoylfloridanolide, 2,10-epoxy-3-dehydroxypseudoanisatin and 7-O-methylpseudomajucin on the basis of spectroscopic data and chemical transformation. The structure of 2, having an ether linkage between C-2 and C-10, has been confirmed by X-ray crystallographic an...

Aerial parts of Inula montana were investigated for its sesquiterpenoid composition. Five sesquiterpene lactones, isoinuviscolide, gaillardin, 1beta-hydroxy-3beta-acetoxy-eudesm-4(15), 11(13)-dien-12-8beta-olide, pulchellin-C and pulchellin-E were identified for the first time in this plant. One of them, 1beta-hydroxy-3beta-acetoxy-eudesm-4(15),11(13)-dien-1 2-8beta-olide, is a novel natural pr...

The aerial parts of A. chrysocoma and A. coarctata afforded 22 and 9 sesquiterpene lactones, respectively. All the compounds described are new for the studied species. The lactones 5, 6 and 12 are new for the genus Achillea.

Phytochemical study on the ethanol extract of the aerial parts of Carpesium abrotanoides led to the isolation of two new sesquiterpene lactones, carabrolactone A (1) and carabrolactone B (2). Their structures were elucidated on the basis of extensive spectroscopic analysis.

Investigation of the ethanol extract of the whole plant of Ainsliaea yunnanensis led to the isolation of four new dimeric sesquiterpene lactones, ainsliadimer F-I (1-4), together with seven known dimeric sesquiterpene lactones (5-11) and ten sesquiterpenes (12-21). Their structures were elucidated by spectroscopic methods. The relative stereochemistry of ainsliadimer F was further confirmed by ...