Phytochemical and bioactive insights into endophytic fungi from Wrightia tinctoria with emphasis on Xylaria rohrensis metabolites potential.

Endophytic fungi represent a prolific reservoir of bioactive compounds with potential therapeutic and biotechnological applications. In this study, nine endophytic fungi were isolated from healthy plant parts of the medicinal plant Wrightia tinctoria and evaluated for their phytochemical profiles, antioxidant properties, and antibacterial activities. Among them, Xylaria rohrensis consistently exhibited the strongest bioactivity, with high levels of phenolic and flavonoid contents, correlating with strong antioxidant activity and growth inhibition of both Gram-positive and Gram-negative bacteria. Based on these results, X. rohrensis was selected for further chemical characterization. Fourier-transform infrared (FTIR) spectroscopy revealed prominent absorption bands corresponding to hydroxyl, carbonyl, and aromatic functional groups, confirming the presence of phenolic and flavonoid compounds. Gas chromatography-mass spectrometry (GC-MS) analysis identified a diverse array of secondary metabolites, including phenolic derivatives, sterols, and fatty acids, several of which are known for their antioxidant and antimicrobial properties. To our knowledge, this is the first detailed report describing the metabolite composition and biological potential of X. rohrensis as an endophyte. Multivariate analyses, including principal component analysis (PCA) and correlation studies, demonstrated clear associations between metabolite abundance and biological activity. These findings highlight X. rohrensis as a promising source of novel natural products and expand our understanding of the functional roles of endophytic fungi in medicinal plants.