Gallic Acid-Rich Ephedra alata: Integrated Phytochemical Profiling, Aromatase Docking, and Optimized Extraction via...

This study investigated the phenolic composition and antioxidant potential of E. alata using an integrated approach combining phytochemical profiling, molecular docking, and Box-Behnken optimization of extraction conditions. Stem extracts were prepared by maceration, sonication, and ultrasound-assisted extraction using dichloromethane, acetone, ethyl acetate, methanol, and methanol/water. Solvent polarity markedly affected extraction efficiency, with methanol and aqueous methanol yielding the highest extraction rates (up to 26.11 ± 0.01%), total phenolics (58.09 ± 1.07 mg GAE/g DW), flavonoids (9.81 ± 0.11 mg CE/g DW), condensed tannins (635.23 ± 3.05 mg CE/g DW), antioxidant capacity (500.46 ± 55.10 mg AAE/g DW), and the lowest DPPH IC₅₀ (0.005 ± 0.001 mg/mL). RP-HPLC-PDA identified nine phenolic compounds, with gallic acid as the predominant constituent. Molecular docking of gallic acid against human aromatase (CYP19A1) revealed favorable binding (ΔG = -5.88 kcal/mol; Ki = 49.38 µM), supported by hydrogen bonding and hydrophobic interactions. Box-Behnken response surface analysis generated significant quadratic models (R² > 0.95), enabling optimization of extraction conditions for maximum phenolic recovery and antioxidant activity. These findings identify E. alata as a promising natural source of gallic acid and bioactive phenolic antioxidants.