A number of studies have suggested a link between hybridization and invasion. In this study, we experimentally test the potential for hybridization to influence invasion through a greenhouse common garden study. Diffuse knapweed (DK) (Centaurea diffusa Lam.) was introduced to North America with admixture from spotted knapweed (SK) (Centaurea stoebe subsp. stoebe L.). Comparisons between North A...

The content of biologically active substances and antioxidant activity in leaves inflorescences three species from the tribe Cynareae Asteraceae family: Centaurea cyanus,Centaurea macrocephala, Rhaponticum carthamoides, grown under conditions Central Siberian Botanical Garden introduction was studied. It determined that contain flavonols, catechins, tannins, carotenoids, pectin substances. high...

New naturally occurring nitrogenous compounds 1 and 2, along with a new dimeric lignan glucoside 3, have been isolated from the ethyl acetate soluble fraction of Centaurea iberica. Their structures have been elucidated through spectroscopic techniques. All the isolated compounds showed significant platelet aggregation inhibition.

The extract containing sesquiterpene lactones of Centaurea iberica (Asteraceae) isolated was separated and a steroidal compound, which is stigmast-1,5-dien-3beta-ol, was purified. The chemical structure was established based on spectroscopic data (UV, IR, MS, 1H NMR, 13C NMR). Both the extract and the compound showed significant antioxidant and antimicrobial activities.

Urophora merzisp. n. reared from flower heads of Centaurea behen Linnaeus is described from Iran. It is similar to Urophora campestris, Urophora sachalinensis, Urophora stylata, Urophora tsoii and Urophora vera in wing pattern with 3 well developed crossbands and indistinct subbasal crossband, differing in aculeus tip with two pairs of diminished preapical steps and different host plants.

Malacitanolide (2), a new eudesmanolide isolated from the aerial parts of Centaurea malacitana, was characterized spectroscopically. The synthesis of 2 from cnicin (1), via the epoxide 3, confirmed the structure and stereochemistry of malacitanolide, as well as its biogenetic relationship with 1. Cytotoxic activity values for 2 are significantly higher than for 1.

Two previously undescribed elemanolide esters, the 2-methylpropanoate and 2-methyl-2-propenoate of 11,13-dehydromelitensin, were isolated in the course of a bioassay-guided fractionation from the aerial parts of Centaurea chilensis Hook. et Arn., used traditionally to treat 'gout and rheumatism'. The mixture of both substances exhibits anti-inflammatory activity in the carrageenan-induced paw e...