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 Pleotrichocladium opacum , 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 ( 8 , 9 , 12 , 15 - 18 , 20, 21 ), along with 15 known ones ( 1 - 7 , 10, 11 , 14 , 19 , 22 - 25 ). Compounds 1 - 9 were detected in fungal extracts from JSA liquid fermentation, compounds 10 - 12 were isolated from a solid rice medium, whereas compounds 14 and 15 were isolated from a solid wheat medium. Addition of 5-azacytidine to the solid rice medium caused the accumulation of compounds 16 - 18 , whereas adding N -acetyl-d-glucosamine triggered the production of two additional metabolites, 19 and 20 . Finally, cocultivation of the fungus Pleotrichocladium opacum with Echinocatena sp. in a solid PDA medium led to the production of five additional natural products, 21 - 25 . 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- J -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.