Macrocyclic trichothecenes in Baccharis coridifolia plants and endophytes and Baccharis artemisioides plants.

Toxic disease in livestock caused by the shrubs Baccharis coridifolia and Baccharis artemisioides is very common in Argentina. The toxicity of Argentinian and Brazilian B. coridifolia plants and of Argentinian B. artemisioides was investigated. The toxicogenic capacity of 15 endothyte isolates of Ceratopicnidium baccharidicola from B. coridifolia was determined. Roridins and verrucarins were analyzed by thin-layer chromatography using a modified Jarvis method. One-hundred per cent of Argentinian B. coridifolia plants were positive for roridins (RA and RE) and verrucarins (VA and VJ), 16.2% for RD and 2.7% for RH. All of the Brazilian B. coridifolia plants were positive only for roridins. In B. artemisioides plants, RA, RE and RD were present in higher concentrations than VA and VJ, and all of them were more concentrated than in B. coridifolia. One-third of the endophyte isolates were toxicogenic for the same roridins and verrucarins, but in very low concentrations. This is the first report of macrocyclic trichothecenes in B. artemisioides, and a new report of B. coridifolia macrocyclic trichothecenes in Argentina.