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.

摘要: Abstract A phytotoxic trisubstituted 2,4-pyridione, named sapinopyridione, was isolated from the culture filtrates of Sphaeropsis sapinea , a fungal pathogen conifers occurring world-wide. Three strains were two cypress species. Strain D-55 Cupressus sempervirens resulted high producer sapinopyridione (12.3 mg l −1 ), whereas strain D-54 same species low (1.1 mg l ); D-50 C. macrocarpa intermediate (5.4 mg l ). Sapinopyridione characterised by spectroscopic and chemical methods, as 6-methyl-2-(2-methyl-1-oxobutyl)-1-oxa-5-azaspiro[2.5]oct-6-ene-4,8-dione. The structure supported preparation three key derivatives, whose antimycotic activities also tested on host plants Seiridium species, virulent agents canker disease. Some structure–activity relationships identified for both phytoxicity antifungal activities. These appear related to presence pyridione oxiran rings. Also carbonyl group side chain seems play role into impart activity.