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Graphical abstract Highlights • Secondary metabolite profile of the endophytic fungus, Anteaglonium sp. FL0768, was found to be affected by culture conditions. • Incorporation of Cu2+ enhanced production of metabolites and drastically affected the polyketide biosynthetic pathway. • The histone acetyl transferase inhibitor, anacardic acid, slightly affected the metabolite profile. • The epigenetic modifiers, 5-azacytidine and suberoyl anilide hydroxamic acid had no effect on its secondary metabolite profile. Abstract In an attempt to explore the biosynthetic potential of endosymbiotic fungi, the secondary metabolite profiles of the endophytic fungus, Anteaglonium sp. FL0768, cultured under a variety of conditions were investigated. In potato dextrose broth (PDB) medium, Anteaglonium sp. FL0768 produced the heptaketides, herbaridine A (1), herbarin (2), 1-hydroxydehydroherbarin (3), scorpinone (4), and the methylated hexaketide 9 S ,11 R -(+)-ascosalitoxin (5). Incorporation of commonly used epigenetic modifiers, 5-azacytidine and suberoylanilide hydroxamic acid, into the PDB culture medium of this fungus had no effect on its secondary metabolite profile. However, the histone acetyl transferase inhibitor, anacardic acid, slightly affected the metabolite profile affording scorpinone (4) as the major metabolite together with 1-hydroxydehydroherbarin (3) and a different methylated hexaketide, ascochitine (6). Intriguingly, incorporaion of Cu2+ into the PDB medium enhanced production of metabolites and drastically affected the biosynthetic pathway resulting in the production of pentaketide dimers, palmarumycin CE 4 (7), palmarumycin CP 4 (8), and palmarumycin CP 1 (9), in addition to ascochitine (6). The structure of the new metabolite 7 was established with the help of spectroscopic data and by MnO 2 oxidation to the known pentaketide dimer, palmarumycin CP 3 (10). Biosynthetic pathways to some metabolites in Anteaglonium sp. FL0768 are presented and possible effects of AA and Cu2+ on these pathways are discussed. [ABSTRACT FROM AUTHOR]

Incorporation of the epigenetic modifier suberoylanilide hydroxamic acid (SAHA) into a potato dextrose broth culture of the endophytic fungus Aspergillus sp. AST0006 affected its polyketide biosynthetic pathway providing two new 3-(4-oxopyrano)-chromen-2-ones, aspyranochromenones A (1) and B (2), and the isocoumarin, (−)-6,7-dihydroxymellein (3). Eight additional metabolites (4 – 11) and two biotransformation products of SAHA (12 – 13) were also encountered. The planar structures and relative configurations of the new metabolites 1 – 2 were elucidated with the help of high-resolution mass, 1D and 2D NMR spectroscopic data and the absolute configurations of 1 – 3 were determined by comparison of experimental and calculated ECD data. Possible biosynthetic pathways to 1 and 2 are presented. Image 1 • The secondary metabolites of Aspergillus sp. AST0006 cultured with the epigenetic modifier SAHA were investigated. • Incorporation of SAHA enhanced production of metabolites and afforded new compounds aspyranochromenones A and B. • Aspyranochromenones A and B contain a new carbon skeleton, despite numerous metabolites are known from Aspergillus spp. [ABSTRACT FROM AUTHOR]