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 C-13-labeled acetate and malonate, and deuterated methionine, a polyketide pathway is proposed for the biosyntheses of phomapyrones. (C) 2004 Elsevier Ltd. All rights reserved.