Chemical and biological characterisation of sapinopyridione, a phytotoxic 3,3,6-trisubstituted-2,4-pyridione produced by Sphaeropsis sapinea, a toxigenic pathogen of native and exotic conifers, and its derivatives
A phytotoxic trisubstituted 2,4-pyridione, named sapinopyridione, was isolated from the culturefiltrates of Sphaeropsis sapinea, a fungal pathogen of conifers occurring world-wide. Three strains were isolated from two cypress species. Strain D-55 isolated from Cupressus sempervirens resulted high producer of sapinopyridione (12.3 mg l(-1)), whereas strain D-54 isolated from the same cypress species