Phomapyrones from blackleg causing phytopathogenic fungi: isolation, structure determination, biosyntheses and biological activity

The isolation and structure determination of phomapyrones D-G, three 2-pyrones and a coumarin, from a group of isolates of the fungal pathogen Leptosphaeria maculans (Desm.) Ces. et de Not., asexual stage Phoma lingam (Tode ex Fr.) Desm, is reported. As well, phomenin B, infectopyrone, and polanrazines B and C were also obtained for the first time from these isolates. In addition, based on results of incorporations of 13C-labeled acetate and malonate, and deuterated methionine, a polyketide pathway is proposed for the biosyntheses of phomapyrones.