UV-mediated antibiotic activity of some compositae species

Roots, leaves, and flowers of 80 species of Compositae were tested for phototoxic activity against Candida albicans. Many genera showed activity, especially in the roots. No active genera were found in the tribe Cichorieae. Phototoxic compounds were isolated from Chrysanthemum leucanthemum florets and Cirsium arvense roots. Chemotaxonomic evidence plus preliminary chemical data suggests that the compounds are polyacetylenic in nature. Unlike other phototoxic compounds, these are inactive against human skin.