Chemical profiling and cytotoxic activity of the endophytic fungus Epicoccum sorghinum isolated from Disynaphia filifolia.

Endophytic fungi are recognized as important sources of bioactive specialized metabolites. In this study, six compounds were isolated from cultures of endophytic fungus Epicoccum sorghinum (DF1) associated with Disynaphia filifolia, including a new aliphatic amide (1) identified as 2-hydroxy-N-(4’-oxohexan-2’-yl)-propanamide and other known compounds 2,3-dihydro-2-hydroxy-2,4-dimethyl-5-trans-propenylfuran-3-one (2), 2,3-dihydro-2-hydroxy-2,4-dimethyl-5-propylfuran-3-one (3), cyclo-L-Pro-L-Phe (4), cyclo-L-Pro-L-Tyr (5) and tetrahydroaltersolanol B (6). The structures were established by spectroscopic analysis and comparison with related compounds reported in the literature. The cytotoxic activities of the isolated compounds were evaluated against human prostate carcinoma (PC-3), cervical carcinoma (HeLa), and non-tumorigenic keratinocyte (HaCaT) cell lines. Among the tested compounds, cyclo-L-Pro-L-Phe showed the most pronounced cytotoxic effects against PC-3 and HeLa cells. The new amide derivative (1) exhibited weak activity toward PC-3 cells and no detectable activity against HeLa cells, while presenting low cytotoxicity toward HaCaT cells. The remaining compounds displayed weak to moderate cytotoxic activity, with PC-3 cells being the most sensitive overall. These findings contribute to the chemical characterization of metabolites produced by E. sorghinum, isolated for the first time from D. filifolia, and highlight its potential as a source of structurally diverse compounds with biological activity to be explored.