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...

Abundances and interactions among biological control insects and their effects on target invasive plants were monitored within the flower heads and roots of diffuse knapweed, Centaurea diffusa, and in spotted knapweed, Centaurea stoebe, along the Colorado Front Range. Flower weevils, (Larinus species) and root-feeders (Cyphocleonus achates and Sphenoptera jugoslavica) were released on knapweed ...

In a complex soil environment, competitive and environmental factors interact with individual traits to influence plant’s root growth patterns ability compete for resources. Here, we examine how of focal plant, Plantago lanceolata L., responds resource heterogeneity presence two neighbor species, Centaurea jacea L.and Poa pratensis L. A full factorial experiment tested the effects nutrient hete...