Pseudonectrins A-D, heptaketides from an endophytic fungus Nectria pseudotrichia.

Four new heptaketides, pseudonectrins A-D (1-4), and four known compounds (5-8) were isolated from cultures of an endophytic fungus Nectria pseudotrichia. Their structures were elucidated primarily by NMR experiments. The absolute configurations of 1-3 and 4 were assigned by electronic circular dichroism calculations and the modified Mosher method, respectively. Compound 1-3 showed moderate cytotoxicity, with IC50 values of 11.6-41.2 µM.