Phyto-and myco-chemical profiling, bioactivity, and in silico docking study of endophytic fungi and host-Setaria flavida.

Endophytic fungi are known to produce a wide array of bioactive compounds with significant pharmaceutical potential. This study focuses on exploring the antioxidant properties of endophytic fungi associated with Setaria flavida (Retz.) Veldkamp, in Karnataka, India. The fungi were isolated and characterized using morphological and internal transcribed spacer (ITS) sequence analyses. Five endophytic isolates were screened for antioxidant activity using spectrophotometric and electrochemical methods. The ethyl acetate extracts of Curvularia protuberata and methanolic extract of S. flavida showed strong antioxidant activity against DPPH, ABTS, H₂O₂, and nitric oxide radicals. Further, C. protuberata and S. flavida metabolites were characterized by Orbitrap High-Resolution Liquid Chromatography-Mass Spectrometer (OHR LC-MS). Molecular docking studies revealed compounds: (22E)-stigmasta-3,5,22-triene, andrographolide, gingerol, nobiletin, retusin, tangeritin, 1-benzoyl-4-(3,5-dibromobenzoyl) piperazine, 2-pyrazolin-5-ol, 5-tridecafluorohexyl-3-methyl-1-(3-pyridylcarbonyl), dexamethasone, griseofulvin, and S-benzyl-N[(benzyloxy)carbonyl] cysteinyltyrosine with potent antioxidant activity, inhibiting enzymes like xanthin oxidase (3NRZ) lipoxygenase (1N8Q) and myeloperoxidase (1DNU). The study suggests that these endophytic fungi and host grass could lead to the production of promising drugs in the pharmaceutical industry.