Phytochemical Profile and Antioxidant Potential of Endophytic Fungi Isolated from the Stem Bark of <i>Oroxylum indicum</i> (L.) Kurz

Objectives This study investigated the antioxidant activity of three fungal endophyte extracts derived from the stem bark of Oroxylum indicum . Material and Methods The fungal endophytes were isolated using PDA media, and their phytochemical screening revealed the presence of alkaloids, phenolics, flavonoids, and tannins. Results Among the three fungal species— Simplicillium (S), Neopestalotiopsis (N), and Trametes (T), Neopestalotiopsis exhibited the highest antioxidant activity. This is the first report of these three endophytes being found in the stem bark of O. indicum . The methanolic extract of Neopestalotiopsis demonstrated strong antioxidant activity, with 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical and superoxide anion radical scavenging percentages of 30.35 ± 0.69 and 35.12 ± 0.32, respectively, at a concentration of 100 μg/mL. Furthermore, the extract showed significant total antioxidant activity, measuring 30.05 ± 0.78 Ascorbic Acid Equivalents. Neopestalotiopsis also had the highest total phenolic content (38.13 ± 0.52 gallic acid equivalents), and total flavonoid content (31.54 ± 0.17 quercetin equivalents) compared to the other two fungal isolates. Based on these results, the fungal endophyte, Neopestalotiopsis clavispora from O. indicum has the potential for development as an antioxidant agent. Conclusion Based on these results, the fungal endophyte, Neopestalotiopsis clavispora from O. indicum has the potential for development as an antioxidant agent.