UPLC-MS metabolite profiling and antioxidant efficacy of Neopestalotiopsisclavispora isolated from Oroxylum indicum (L.) Kurz Stem Bark

Abstract

Endophytic fungi represent a valuable source of bioactive compounds with diverse pharmacological properties. In this study, we explored the antioxidant potential of secondary metabolites produced by Neopestalotiopsis clavispora (N.clavispora), an endophytic fungus isolated from Oroxylum indicum Kurz stem bark. N.clavispora extract was subjected to UPLC-MS analysis to profile its bioactive components, and its antioxidant capacity was assessed using the DPPH (1,1-diphenyl-2-picrylhydrazyl) free radical scavenging assay. For in vivo evaluation, Swiss albino mice were administered with 100 mg/kg bodyweight dose of extract for five consecutive days, followed by exposure to 2 Gy of gamma radiation at a dose rate of 3.58 Gy/min. Subsequent measurements of superoxide dismutase (SOD) activity in liver homogenate were conducted to assess antioxidant enzyme response. The data obtained from UPLC-MS, showed, cimicifoetiside B (identified by UNIFI database matching; 44% relative abundance) as the predominant metabolite. N. clavispora extract showed moderate DPPH scavenging (IC₅₀ 82.86 μg/mL vs ascorbic acid 19.01 μg/mL). Molecular docking using cimicifoetiside B against the antioxidant enzyme Superoxide dismutase (SOD), revealing a docking score of −4.96 kcal/mol with 1 hydrogen bond. Molecular dynamics simulations confirmed the interaction with a binding energy of –12.36 ± 02.32 kcal/mol. Binding affinities and molecular interaction profiles indicated possible association with SOD. In vivo, N.clavispora extract at 100 mg/kg body weight/day yielded SOD activity of 1.98 ± 0.38 vs. radiation group 0.78 ± 0.13. These results suggest N.clavispora may have antioxidant related activity under the conditions tested, supporting further in vitro and in vivo studies.