Pseudonectrins A–D, heptaketides from an endophytic fungus Nectria pseudotrichia†
Abstract
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.