Anthraquinones from some Drechslera species and Bipolaris sorokiniana

The red pigments exudated from Drechslera teres, D. graminea, D. tritici-repentis, D. phlei, D. dictyoides, D. avenae and Bipolaris sorokiniana , were extracted and isolated by means of thin-layer chromatography and/or high-performance liquid chromatography. Chemical characterization was made by spot-tests, uv-vis spectrophotometry and 1 H-nuclear magnetic resonance spectroscopy. The red pigment produced by the five first-mentioned Drechslera species was identified as the anthraquinone catenarin while that form D. avenae and B. sorokinana consisted of two other anthraquinones — cynodontin and helminthosporin. Catenarin was totally inhibitory against the Gram-positive bacterium Bacillus subtilis but not the Gram-negative bacterium Erwinia carotovora . However, catenarin could also partly inhibit the mycelium of D. teres itself.