Secondary Metabolites, including a New 5,6-Dihydropyran-2-One, Produced by the Fungus . Aphicidal Activity of the Main Metabolite, Sphaeropsidin A.

An undescribed 5,6-dihydropyran-2-one, namely diplopyrone C, was isolated and characterized from the cultures of an isolate of the fungus recovered from in Algeria. The structure and relative stereostructure of (5,6S,7,9,10)-5-hydroxy-6-(2-(3-methyloxiran-2-yl)vinyl)-5,6-dihydro-2H-pyran-2-one were assigned essentially based on NMR and MS data. Furthermore, ten known compounds were isolated and identified in the same cultures. The most abundant product, the tetracyclic pimarane diterpene sphaeropsidin A, was tested for insecticidal effects against the model sucking aphid, . Results showed a toxic dose-dependent oral activity of sphaeropsidin A, with an LC of 9.64 mM.