New metabolites produced by endophyte Clonostachys rosea B5 − 2

The endophytic fungus, Clonostachys rosea B5-2 was isolated from mangrove plants and subjected to the one strain many compounds (OSMAC) methodology. By this approach, it was found that modification of the culture media enhanced the production of secondary metabolites by C. rosea B5-2. The apple juice supplemented solid rice media led to significant changes in the secondary metabolism of the fungus, C. rosea B5-2, and induced the production of four new compounds, (-)-dihydrovertinolide (2), and clonostach acids A (3), B (4), and C (5) together with the known compound, (-)-vertinolide (1). The new compound (-)-dihydrovertinolide (2) exhibited phytotoxicity against lettuce seedlings at a concentration of 50 mg L−1.