NMR-based metabolic profiling and antioxidant activity of Eleutherine bulbosa bulb ethanol extract

The metabolite profile of the ethanol extract from Eleutherine bulbosa was assessed using the 1D NMR approach amalgamated with 2D NMR. E. bulbosa, an indigenous plant found in Indonesia, possesses considerable promise as a raw material for medicinal products. We examined the antioxidant capacity of the E. bulbosa extract using DPPH and ABTS methods. The antioxidant evaluation demonstrated that the ethanol extract exhibits strong antioxidant properties. Furthermore, we have successfully identified thirteen metabolites in the ethanol extract without separation. These metabolites include eleutherol A, eleutherol B, eleutherol C, eleuthione B, eleuthione C, hongconin, karwinaphthol, isoeleuthoside C, quinic acid, chlorogenic acid, isoeleutherin, cyanidin-3-o-β-glucopyranoside, and kadsuric acid. Metabolite Cyanidin-3-o-β-glucopyranoside (4.89 mM ± 0.02) was the highest metabolite contained in this extract. This result showed that NMR methods could detect and measure metabolites in the E. bulbosa ethanol extract without requiring separation.