Phytochemical profiling, antioxidant activity, and allelopathic potential of Jatropha podagrica Hook. leaf extract and fractions

Jatropha podagrica Hook. is a promising source of bioactive compounds with potential applications in agriculture and medicine. This study investigated the phytochemical composition, antioxidant activity, and allelopathic potential of methanolic crude extract and solvent fractions from J. podagrica leaves. Dried leaf powder was extracted with methanol and sequentially fractioned into hexane, ethyl acetate, and aqueous fractions.. Among the frations, the ethyl acetate fraction exhibited the highest TPC (41.79 mg GAE/g dry weight) and the strongest antioxidant activity, showing the lowest IC 50 values in both DPPH and ABTS assays. Pearson’s correlation analysis revealed strong negative correlations between TPC and DPPH IC 50 (r = − 0.909) and between TPC and ABTS IC 50 (r = − 0.965), indicating that phenolic compounds substantially may contribute to antioxidant activity. In allelopathic bioassays, the ethyl acetate fraction showed the strongest inhibitory effects on root and shoot growth of both test species, with particularly pronounced activity against E. crus-galli . GC–MS analysis tentatively identified 60 compounds belonging to various chemical classes, including phenolics, coumarins, ketones, esters, alcohols, and other secondary metabolites that may contribute to the observed bioactivities. Overall, the results suggest that phenolic-rich fractions of J. podagrica possess considerable antioxidant and allelopathic activity and may represent promising sources of natural bioactive compounds for agricultural and pharmaceutical applications.