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

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.