Chemical Profiling and Redox-Target Mapping of Antioxidant Fractions from Sphagneticola trilobata: An Integrated...

Background/Objectives: Sphagneticola trilobata is a phytochemically rich medicinal plant, yet its antioxidant-active fractions and redox-related mechanisms remain incompletely characterized. This study combined metabolite profiling, antioxidant screening, network pharmacology, pharmacokineticprediction, and molecular docking to characterize active flower and leaf fractions and prioritize antioxidant-related targets. Methods: Petroleum ether, methylene chloride, and ethyl acetate fractions of S. trilobata flowers and leaves were analyzed by ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS). The predominant metabolite was isolated and spectroscopically characterized. Antioxidant activity was assessed using 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) and ferric reducing antioxidant power (FRAP). Metabolites from the most active fractions were investigated by target prediction, protein-protein interaction (PPI) analysis, enrichment analysis, SwissADME, and docking. Results: UPLC-ESI-MS/MS tentatively identified 59, 18, and 16 metabolites in the petroleum ether, methylene chloride, and ethyl acetate fractions, respectively, including diterpenes, phenolic acids, flavonoids, fatty acids, triterpenes, and coumarin-related metabolites. Butein was isolated as the predominant metabolite from the ethyl acetate flower fraction, which showed the strongest antioxidant activity, with IC₅₀ values of 5.85 ± 0.14 µg/mL in ABTS and 9.11 ± 0.75 µg/mL in FRAP, followed by the ethyl acetate leaf fraction. Network analysis identified 61 and 82 antioxidant-relevant targets for the flower and leaf ethyl acetate fractions, respectively, with enrichment in inflammation-, apoptosis-, transcription-, hypoxia-, lipid stress-, and kinase-related pathways. Docking suggested fraction-specific compatibility with EGFR/PTGS2/STAT3 for flower metabolites and AKT1/PTGS2 for leaf metabolites. Conclusions: S. trilobata ethyl acetate fractions, particularly the flower fraction, represent promising antioxidant sources with experimentally supported activity and computationally prioritized redox-related hypotheses requiring further validation.