OSMAC Approach and Cocultivation for the Induction of Secondary Metabolism of the Fungus Pleotrichocladium opacum .

The application of an OSMAC (One Strain-Many Compounds) approach on the fungus , isolated from a soil sample collected on the coast of Asturias (Spain), using different culture media, chemical elicitors, and cocultivation techniques resulted in the isolation and identification of nine new compounds (, , , -, ), along with 15 known ones (-, , , , -). Compounds - were detected in fungal extracts from JSA liquid fermentation, compounds - were isolated from a solid rice medium, whereas compounds and were isolated from a solid wheat medium. Addition of 5-azacytidine to the solid rice medium caused the accumulation of compounds -, whereas adding -acetyl-d-glucosamine triggered the production of two additional metabolites, and . Finally, cocultivation of the fungus with sp. in a solid PDA medium led to the production of five additional natural products, -. The structures of the new compounds were elucidated by HRESIMS and 1D and 2D NMR as well as by comparison with literature data. DP4+ and mix--DP4 computational methods were applied to determine the relative configurations of the novel compounds, and in some cases, the absolute configurations were assigned by a comparison of the optical rotations with those of related natural products.